earthing and Lightning Protection Technical Specification
Logo Cliente / Customer logo CP / PC BO1001 BO1000 BO1002 Proyecto / Project: Termoeléctrica del Sur, Warnes & Entre
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Logo Cliente / Customer logo
CP / PC
BO1001 BO1000 BO1002 Proyecto / Project:
Termoeléctrica del Sur, Warnes & Entre Ríos Código contenido / Contents Code
Responsable / Responsible Party
00BAU DCC Doc. Class. Code.
EEC102
Suministrador / Supplier
TSK Index/ Rev
Código de Documento Siemens / Siemens Document Number:
Version
-
-
BO1001-00BAU-EEC102-448220640
Número de página Page Number
Código de documento Suministrador / Supplier Document Number
000570-00-ELC-ET-0012
Format
1/88
Título del documento / Document Title:
A4
Unid
Earthing and Lightning Protection Technical Specification Manejo / Handling
448220640
Restricted
Export Control Classification
AL:
ECCN:
N
N
Cambios / Changes:
-
2016-07-18
J.J.R.
P.G.G.
P.G.G.
First Issue
Rev.
Date Fecha
Prepared by Realizado
Reviewed by Revisado
Approved by Aprobado
Remarks Comentarios
© This document must not be copied or disclosed to third parties without TSK consent.
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
2/88
TABLE OF CONTENTS: 1
2
3
INTRODUCTION ..................................................................................................6 1.1
GENERAL PROJECT DESCRIPTION .................................................................................... 6
1.2
PURPOSE ................................................................................................................................ 6
1.3
CONFIDENTIALITY ................................................................................................................. 6
1.4
RESPONSIBILITIES AND ALTERNATIVES .......................................................................... 6
SCOPE OF SUPPLY............................................................................................7 2.1
GENERAL CONSIDERATIONS .............................................................................................. 7
2.2
EQUIPMENT AND COMPONENTS ........................................................................................ 8
2.3
SERVICES ............................................................................................................................... 8
2.4
SPARE PARTS ........................................................................................................................ 8
2.5
SPECIAL TOOLS, CONSUMABLES, LUBRICANTS AND MAINTENANCE ........................ 9
2.6
LABELLING ............................................................................................................................. 9
2.7
EQUIPMENT AND SERVICES TO BE SUPPLIED BY THIRD PARTIES ............................ 10
2.8
BATTERY LIMITS ................................................................................................................. 10
2.9
DEVIATIONS FROM THE SPECIFICATION ........................................................................ 10
CODES, STANDARDS AND REFERENCE DOCUMENTATION ......................11 3.1
GENERAL CONSIDERATIONS ............................................................................................ 11
3.2
COMPLIANCE WITH THE REGULATIONS ......................................................................... 12
3.3
APPLICABLE STANDARDS................................................................................................. 12
3.4
REFERENCE DRAWINGS, SPECIFICATIONS AND DOCUMENTS .................................. 13
3.5
OTHER CONSIDERATIONS ................................................................................................. 14
4
SITE DATA.........................................................................................................15
5
LIGHTNING PROTECTION ...............................................................................16 5.1
DEFINITIONS ........................................................................................................................ 16
Project: Bolivia Combined Cycles Power Plants
Projectcode
Document Title:
BO1001 BO1000 BO1002 Logo Originator
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
3/88
5.1.1
General ........................................................................................................................... 16
5.1.2
Lightning Protection Zone (LPZ) .................................................................................... 16
5.1.3
Lightning Protection Level (LPL), ................................................................................... 17
5.2
EXTERNAL LIGHTNING PROTECTION .............................................................................. 19
5.2.1
General ........................................................................................................................... 19
5.2.2
Rolling Sphere Method ................................................................................................... 19
5.2.3
Protection Angle Method ................................................................................................ 19
5.2.4
Other Methods................................................................................................................ 19
5.2.5
Lightning Protection of Building/Structure ...................................................................... 20
5.2.5.1
General ....................................................................................................................... 20
5.2.5.2
Minimum Design Requirements for Materials ............................................................ 20
5.2.5.3
Air Terminals .............................................................................................................. 20
5.2.5.4
Down Conductors ....................................................................................................... 21
5.2.5.5
Cross Conductors ...................................................................................................... 21
5.2.6
Metal Enclosed Power Control Centre (PCC) ................................................................ 22
5.2.7
Outdoor Cable Routes ................................................................................................... 22
5.3
5.2.7.1
General ....................................................................................................................... 22
5.2.7.2
Reinforced in-situ Concrete Cable Ducts ................................................................... 22
5.2.7.3
Shielded Buried Cable Conduits ................................................................................ 22
5.2.7.4
Cable Conduits Below Reinforced Foundations ........................................................ 23
5.2.7.5
Unshielded Buried Cable Conduits ............................................................................ 23
5.2.7.6
Other Cable Ducts ...................................................................................................... 23
5.2.7.7
Earth Buried Cables ................................................................................................... 23
5.2.7.8
Outdoor Cable Routes above Ground ....................................................................... 23
INTERNAL LIGHTNING PROTECTION ............................................................................... 24
Project: Bolivia Combined Cycles Power Plants
Projectcode
Document Title:
BO1001 BO1000 BO1002 Logo Originator
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
6
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
4/88
5.3.1
General ........................................................................................................................... 24
5.3.2
Equipotential Bonding .................................................................................................... 24
5.3.3
Surge Protection Devices (SPD) .................................................................................... 25
EARTHING .........................................................................................................26 6.1
GENERAL .............................................................................................................................. 26
6.2
OUTDOOR EARTHING SYSTEM ......................................................................................... 26
6.2.1
General ........................................................................................................................... 26
6.2.2
Meshed Buried Earth Electrodes (BEE) ......................................................................... 26
6.2.3
Buried Earth Ring Electrode (BERE) ............................................................................. 27
6.2.4
Foundation Earth Electrode (FEE) ................................................................................. 27
6.2.5
Outdoor Earthing Terminal ............................................................................................. 27
6.3
7
Prep. By
INDOOR EARTHING SYSTEM ............................................................................................. 27
6.3.1
General ........................................................................................................................... 27
6.3.2
Main Earthing Conductors .............................................................................................. 28
6.3.3
Earthing Conductors ...................................................................................................... 28
6.3.4
Additional Potential Grading Conductors ....................................................................... 28
6.3.5
Steel Columns and Metal Base-frames ......................................................................... 28
6.3.6
Indoor Earthing Terminal ................................................................................................ 28
MEASURES AGAINST ELECTROMAGNETIC INTERFERENCES ..................30 7.1
GENERAL .............................................................................................................................. 30
7.2
ELECTRICAL AND ELECTRONIC DEVICES ...................................................................... 30
7.3
OUTDOOR LAID CABLES.................................................................................................... 30
7.3.1
General ........................................................................................................................... 30
7.3.2
Instrumentation and Control (I&C) Cables ..................................................................... 31
7.3.3
Power Cables ................................................................................................................. 32
7.4
I&C POWER SUPPLY REFERENCE CONDUCTOR (M)..................................................... 34
Project: Bolivia Combined Cycles Power Plants
Projectcode
Document Title:
BO1001 BO1000 BO1002 Logo Originator
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
8
9
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
5/88
7.5
SEPARATION OF CABLES .................................................................................................. 34
7.6
SEPARATION DISTANCE BETWEEN CABLE ROUTES AND LPS................................... 34
INSPECTIONS AND TESTS ..............................................................................36 8.1
INSPECTIONS ....................................................................................................................... 36
8.2
CERTIFICATES ..................................................................................................................... 36
QUALITY REQUIREMENTS ..............................................................................37 9.1
QUALITY CONTROL PLAN .................................................................................................. 37
9.2
INFORMATION TO BE PROVIDED WITH THE OFFER ...................................................... 38
9.3
INFORMATION AFTER THE CONTRACT ........................................................................... 38
9.4
INSPECTION AND TEST PLAN (ITP) .................................................................................. 40
10 PROJECT CONTROL AND DOCUMENTATION ..............................................41 10.1
GENERAL REQUIREMENTS................................................................................................ 41
10.2
DOCUMENTATION REQUIREMENTS ................................................................................. 41
10.3
DOCUMENTS TO BE PROVIDED WITH THE OFFER ........................................................ 43
10.4
DOCUMENTS TO BE PROVIDED AFTER ORDER ACCEPTANCE ................................... 44
10.5
FINAL DOSSIERS ................................................................................................................. 44
10.5.1
Documents to be included in the technical dossier ........................................................ 45
10.5.2
Documents to be included in the manufacturing dossier ............................................... 45
10.5.3
Documents to be included in the erection dossiers ....................................................... 46
10.5.4
Documents to be included in the commissioning dossier .............................................. 47
ATTACHMENT A ......................................................................................................49 ATTACHMENT B ......................................................................................................53 ATTACHMENT C ......................................................................................................56
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
6/88
1 INTRODUCTION 1.1 GENERAL PROJECT DESCRIPTION The Consortium formed by Siemens and TSK has been selected to execute, under EPC modality, three (3) Thermoelectric Power Plants in Bolivia: -
Termoeléctrica de Warnes, that will be located near Warnes (Santa Cruz), and will consist on Two (2) blocks of Combined Cycle Power Plants on 2x1 configuration + Two (2) blocks of Steam Tailing Power Plants on 2x1 configuration, all of them based on a Wet Cooling Technology.
-
Termoeléctrica del Sur, that will be located near Yaguacua (Yacuiba), and will consist on Two (2) blocks of Combined Cycle Power Plants on 2x1 configuration + Two (2) blocks of Steam Tailing Power Plants on 2x1 configuration, all of them based on a Dry Cooling Technology.
-
Termoeléctrica de Entre Ríos, that will be located near Entre Ríos (Cochabamba), and will consist on Three (3) blocks of Combined Cycle Power Plants on 2x1 configuration, all of them based on a Wet Cooling Technology.
1.2 PURPOSE The purpose of this document is to specify the requirements for the design, manufacturing, cleaning, painting, shop testing, delivery, transport including insurance, erection supervision, commissioning and start up supervision of the earthing and lightning protection systems.
1.3 CONFIDENTIALITY Any document exchanged, whether in digital format or on paper, (including this specification) shall be kept in strict confidentiality. It is strictly forbidden to extract or reproduce any part of said documents.
1.4 RESPONSIBILITIES AND ALTERNATIVES VENDOR shall be responsible not only for fulfilment of the requirements specified herein, but also for the design, adequate selection of materials, appropriate manufacture, erection, commissioning and tests for a safe and reliable operation in accordance with the legally applicable codes, standards and requirements at European, Bolivian, regional and local level, as well as with the specifications and associated documentation.
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
7/88
2 SCOPE OF SUPPLY 2.1 GENERAL CONSIDERATIONS The complete supply of the equipment within the battery limits defined in the project is required. The scope shall include the execution and supply by the VENDOR of all the work, materials or services in general, including those not expressly indicated in the text but necessary for the proper operation of the facility’s equipment and systems. The VENDOR shall supply all components or services required for the satisfactory operation of the facility, without any additional cost for the Buyer. The VENDOR shall take care that the scope of supply includes all the components necessary for a proper and safe operation. The equipment supplied shall be designed taking into account the access points in order to facilitate the inspection, cleaning, maintenance and repair activities. These accesses must be included in the supply. All the items of equipment shall be new and shall incorporate state-of-the-art technology in its area that has been duly tested in similar uses (no prototypes shall be accepted). The Supply shall comply with the terms and conditions figuring in this Technical Specification relating to operational requirements, design and construction criteria, guarantees and delivery times. All the requirements or recommendations commonly established for the design, material selection, manufacture, inspections, tests, preparation for shipment and commissioning of this type of equipment and facilities shall be observed in accordance with good practice and are included in the VENDOR’s scope. The VENDOR shall have adequate technical assistance and maintenance services. The Tender shall include and quote all the works, materials and services in general that are not expressly mentioned in the text, but that are necessary for the proper operation of the facility. In case of contradiction among the various requirements included in this technical specification (and annexes), the other contractual technical specification and/or the applicable standards or regulations, the one to be applied is the most restrictive one, the one which gives better performance or benefit to the Purchaser. In any case, the Purchaser reserves the right to decide which of the different requirements are to be fulfilled. In case of contradiction, only the purchaser by a written statement is able to decide which is the compulsory requirement to be finally applied. The supply shall follow the local region and Bolivian laws, regulations or instructions by the authorities whenever deemed to do so, specially those related to Health, Safety and Environment. When there is not any explicit Directive the Codes and Standards listed in the Technical Specification shall be applied. The Contractor shall provide any document or certification requested by the authorities related to these requirements. Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
8/88
The Supplier shall be responsible for the complete design, procurement of materials and equipment, manufacturing, inspection and factory testing, cleaning, coating, packing protection for shipment, transport to site and unloading of earthing and lightning systems as detailed in this technical specification. The Supplier shall also be responsible for submitting to the Purchaser the information, data, calculations, risk analysis, drawings, procedures, certificates and other documents, as may be required by this specification, the applicable codes and standards and other reference documents specified herein. Should the Supplier wish to subcontract any of the work covered by this specification, it is his responsibility to ensure that his subcontractors are made fully aware of the relevant requirements of this specification.
2.2 EQUIPMENT AND COMPONENTS The scope of supply shall include all the equipment necessary for earthing and lightning protection systems of the power plants of the projects of Warnes, Del Sur and Entre Ríos.
2.3 SERVICES •
Packing, shipping and transport, in accordance with the requirements in the purchasing conditions.
•
Performance of the tests in Chapter 8 herein.
•
Supply of the documentation listed in Chapter 10 of this specification.
•
Transportation to site (quoted as optional).
2.4 SPARE PARTS The VENDOR shall provide a list of recommended spares and fittings for all the equipment and auxiliary devices supplied. The list shall include the part name, and specify its kind and main characteristics, replacement frequency, delivery time, quantities and price. This recommendation shall be coherent with the instructions given in the Supply Operation and Maintenance Manual. The spares recommended and subsequently quoted by the VENDOR in the contract, after approval by the Buyer, shall cover the following: •
Spares for start-up and commissioning up to the final acceptance test.
•
Spares for one (1) year operation.
•
Spares for five (5) years operation (optional scope). The period of validity of the spares quoted for five (5) years operation shall be established in the contract of supply.
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
9/88
After contract, spare parts list for operation shall be submitted by Vendor according to a specific template to be provided by the Buyer. The materials to be used during the erection, testing and commissioning activities up to the acceptance test shall not be considered as spares and shall be supplied with the main items of equipment as part of the contract. If during said period it were necessary to use any component included in the Buyer’s stock of spares, said components shall be considered to be lent by the VENDOR with no additional cost. The spares shall be marked and packaged so that they are protected against damage, deformation, loss, etc. during transport and storage. The VENDOR shall indicate the storage requirements of the spares, if any. The delivery time for spare parts shall be agreed upon so that the first set of spares reaches the Purchaser Plant before equipment tests are commenced.
2.5 SPECIAL TOOLS, CONSUMABLES, LUBRICANTS AND MAINTENANCE If necessary, the VENDOR shall provide a list identifying all the special tools required for the operation and maintenance of the equipment and auxiliary devices supplied in accordance with the Supply Operation and Maintenance Manual. The VENDOR shall specify if special hoisting devices are required for the assembly or disassembly of parts of the equipment supplied. The VENDOR shall identify and include in its costs the special tools required for the erection of the equipment and auxiliary devices supplied, as well as those that could be used for operation and maintenance activities. All the tools accepted to be supplied under the contract shall be referenced taking into consideration its use in the application of the Supply Operation and Maintenance Manual. After contract, special tools, consumables, lubricants and maintenance measures list shall be submitted by Vendor according to a specific template to be provided by the Buyer.
2.6 LABELLING All the components included in the scope of supply, marked with KKS classifications, shall be supplied by the VENDOR with provisional KKS labels made of plastic or similar. Additionally, permanent labels according to the technical specification BO1001-20111-AEC102-447981252 shall be supplied by the VENDOR separately for final installation by the purchaser. Permanent labels shall be in Spanish.
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
10/88
2.7 EQUIPMENT AND SERVICES TO BE SUPPLIED BY THIRD PARTIES The following equipment and services shall be supplied by third parties and, therefore, are not included in the scope of supply of this specification: •
Water and/or electricity consumed on site during the erection, commissioning and testing activities.
•
Civil works and foundations.
•
Assembly, erection and commissioning.
•
External wiring.
2.8 BATTERY LIMITS The supply will only include the equipment necessary for earthing and lightning protection systems.
2.9 DEVIATIONS FROM THE SPECIFICATION In accordance with the provisions figuring in Section 1.4, the VENDOR may propose deviations to the Technical Specification. Such deviations shall be expressly identified, justified and accepted in writing by the Buyer.
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
11/88
3 CODES, STANDARDS AND REFERENCE DOCUMENTATION 3.1 GENERAL CONSIDERATIONS The VENDOR shall comply with the requirements figuring in the codes and standards mentioned in this Specification, as well as with all those figuring in the rest of the contractual documents. Should there be any discrepancy between this Technical Specification and the codes or standards listed, the most stringent criterion shall always prevail. The standards, codes, calculation basis and procedures and, generally, the technical criteria to be applied to the project and execution of the supply shall be approved by the Buyer. No modification shall be made to the technical conditions approved by the Buyer without its prior written authorization. The approval by the Buyer shall not exempt the VENDOR from its responsibilities. The Supply shall comply with said codes, standards, specifications and documentation (always in their latest and valid editions and addenda, unless otherwise specified). The VENDOR shall be responsible for complying with all the requirements figuring in the Bolivian regulations and legislation, in the National and Local Codes and in any other applicable document during the life of the contract. Should there be any discrepancy between the requirements figuring in the various documents, the following order of prevalence shall apply: •
Legal requirements
•
Technical specification
•
Datasheets
•
Documents attached to the Technical Specification
•
Codes and documents referenced in the Technical Specification
•
Other applicable codes and standards
The VENDOR shall be responsible to ensure that any conflict between documents that could compromise the purchase order be settled and agreed in writing with the Buyer before starting the manufacture or construction of the parts affected. The VENDOR could be requested to attend a meeting with the Buyer for design review and coordination purposes before the start of the manufacturing process. Should this request or any other document, code, standard, etc., mentioned establish various requirements that make reference to the same concept, the most stringent one shall apply. Project: Bolivia Combined Cycles Power Plants
Projectcode
Document Title:
BO1001 BO1000 BO1002 Logo Originator
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
12/88
Should the VENDOR detect any such conflict, it shall inform the Buyer within a maximum of 5 working days.
3.2 COMPLIANCE WITH THE REGULATIONS All the equipment and components supplied, and all the works performed, shall comply with all Bolivian regulations, laws and requirements that apply to the Owner (including any future modification to the regulations), laws and requirements during the period of the Purchase contract. The VENDOR or its subcontractors shall fully comply with the applicable Regulations and/or local, regional, national (Bolivia) and international requirements. The Supplier shall supply the official documentation required to obtain all the permits up to the commissioning phase. Special attention shall also be paid to: -
Bolivian electrical regulations related to low voltage, high voltage and complementary technical instruction
-
Bolivian and local laws on Health and Safety in the Workplace.
3.3 APPLICABLE STANDARDS As a general rule, the latest versions of the industrial standards shall be followed. They shall be applied provided that they do not contradict legally binding local regulations. Nevertheless, they can be replaced by other equivalent international standards of recognized prestige. In this case, the VENDOR shall inform the Buyer and the latter reserves the right to include said additional requirements. The design, materials, manufacture, construction, tests, cleaning, coating, packaging, etc. of all equipment and components included in the scope of this document shall comply with the applicable standards, published by the standardization associations listed below. Should there be any discrepancy between the standards; the most stringent criterion shall always be applied. •
IEC 62305-1 Protection against lightning - Part 1: General principles.
•
IEC 62305-2 Protection against lightning - Part 2: Risk management.
•
IEC 62305-3 Protection against lightning - Part 3: Physical damage to structures and life hazard.
•
IEC 62305-4 Protection against lightning - Part 4: Electrical and electronic systems within structures.
•
IEEE Standard 80-2013 – IEEE Guide for Safety in AC Substation Grounding.
•
IEC 61000 Electromagnetic compatibility (EMC).
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
13/88
•
EN 13601 Copper and copper alloys - Copper rod, bar and wire for general electrical purposes.
•
UNE 21186 Protection against lightning: Surge arresters using early streamer emission air terminals.
•
NFC 17102 Protection against lightning: Early streamer emission lightning protection systems.
The last edition of the standard in force on the date that the request for tender is received shall apply. Should there be any discrepancy between the standards and this specification, or between sections of this specification, the VENDOR shall inform the Buyer in order to settle it. Should there be any conflict, it shall be reported and the most stringent criterion selected, unless otherwise expressly indicated by the Buyer. The VENDOR shall be responsible to be well informed about the codes and standards referenced above. Should any change or modification to the equipment be required in order to comply with the standards, it shall be to the account of the VENDOR.
3.4 REFERENCE DRAWINGS, SPECIFICATIONS AND DOCUMENTS The following documents shall be considered by the VENDOR in the proposal: •
BO1000-11630-MQZ104-447999745 General Plant Data of Warnes.
•
BO1001-11630-MQZ104-447999738 General Plant Data of Del Sur.
•
BO1002-11630-MQZ104-447999752 General Plant Data of Entre Ríos.
•
BO1001-11620-AEC102-447981238 KKS Identification System Application Guide.
•
BO1001-20111-AEC102-447981252 Labelling Technical Specification
•
BO1001-11630-EEC102-448220541 Electrical Design Criteria.
•
BO1001-00BAU-ETC104-448220695 Typical Details of Earthing Grid.
•
BO1000-00BAU-EEZ105-448223382 General Earthing Calculation Report of Warnes.
•
BO1000-00BAU-ELH106-448223399 Underground Earthing Grid Arrangement of Warnes.
•
BO1000-00BAU-ELU102-448223405 Lightning Protection General Arrangement of Warnes.
•
BO1001-00BAU-EEZ105-448220916 General Earthing Calculation Report of Del Sur.
•
BO1001-00BAU-ELH106-448221067 Underground Earthing Grid Arrangement of Del Sur.
•
BO1001-00BAU-ELU102-448221098 Lightning Protection General Arrangement of Del Sur.
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
14/88
•
BO1002-00BAU-EEZ105-448223412 General Earthing Calculation Report of Entre Ríos.
•
BO1002-00BAU-ELH106-448223429 Underground Earthing Grid Arrangement of Entre Ríos.
•
BO1002-00BAU-ELU102-448223436 Lightning Protection General Arrangement of Entre Ríos.
3.5 OTHER CONSIDERATIONS The following criteria shall be considered for this project: •
Language: English. Additionally O&M Manual and training courses shall also be submitted in Spanish. Equipment nameplates and labels shall be in Spanish. Other documents that may be required in Spanish language shall be specified by Buyer before contract awarding.
•
Engineering Units: International System of Units (SI)
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
15/88
4 SITE DATA The specific data of these three (3) Thermoelectric Power Plants in Bolivia, such as design temperatures, seismic data, wind conditions, etc, are defined in the following documents: -
Del Sur: “BO1001-11630-MQZ104-447999738_General Plant Data”
-
Warnes: “BO1000-11630-MQZ104-447999745_General Plant Data”
-
Entre Ríos: “BO1002-11630-MQZ104-447999752_General Plant Data”
These three (3) documents are attached to the Purchase Request.
Project: Bolivia Combined Cycles Power Plants
Projectcode
Document Title:
BO1001 BO1000 BO1002 Logo Originator
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
16/88
5 LIGHTNING PROTECTION 5.1 DEFINITIONS 5.1.1
General
Every building/structure and area is assigned to a certain Lightning Protection Level (LPL) and Lightning Protection Zone (LPZ). Each LPL and LPZ has individual civil requirements for lightning protection and shielding. At the interface point between different LPZ’s, additional measures are to be taken to prevent interferences.
5.1.2
Lightning Protection Zone (LPZ)
Lightning protection zone (LPZ) is a zone which classifies the degree of danger from either induction effects or electromagnetic fields both caused by a lightning strike to the plant. Assigning a LPZ to the various buildings/structures and areas within the power plant area represents a risk assessment of lightning strikes. The main goal is to avoid damages to equipment and to achieve a reliable operation of all systems. Further information describing the lightning protection zones is stated in relevant standards as indicated in section 3.3. •
Lightning Protection Zone 0A (LPZ 0A). In this zone, direct lightning strikes are possible. Full and partial lightning currents and electromagnetic fields occur. There is no protection against direct lightning strikes.
•
Lightning Protection Zone 0B (LPZ 0B). In this zone, partial lightning currents and full electromagnetic fields occur. There is protection against direct lightning strikes.
•
Lightning Protection Zone 1 (LPZ 1). In this zone, lightning currents are reduced due to the lightning current distribution. Zone 1 is within buildings/structures protected against direct lightning strikes. The electromagnetic field is reduced by the electromagnetic shielding of the building/structure. The LPZ 1 shielding effects in buildings are ensured normally by the combination of a dense-meshed foundation earthing grid, a conductively interconnected wall-cladding and a roof realized by metal sheets or at least equipped with a dense-meshed air-termination system. Similar shielding effects could also be achieved by a dense-meshed interconnection of the reinforcement-structures of concrete buildings. LPZ 1 for cable routes with shielding effects can be generated: o
by closed continuous reinforced cable ducts
o
by duct banks encased with reinforcement steel mats
o
by open-air cable support system being metal-enclosed
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o
by open-air cable support system if cable troughs with cover are used
o
by shielded cables
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A preliminary list of LPZ for buildings/structures and areas of power plant is outlined below: Building GT enclosed structure ST enclosed structure Boiler Trasformer yard Electrical module Control building Water treatment plant building Warehouse building Air cooler condenser Emergency diesel module Black Start diesel module Cable trench Pipe rack and cable bridge Reinforced in-situ cable-ducts Underground cable ducts without continuous reinforcement Underground cable duct banks, shielded Cable trays with cover Protected outdoor areas Unprotected outdoor areas Note 1 ≡ In the case of new control building.
LPZ 1 1 1/0B 0B 1 1 (Note 1) 1 1 1 1 1 1 0B 1 0B 1 1 0B 0A
The final LPZ for buildings/structures and areas shall be obtained from the lightning calculations. The list of LPZ applicable to the projects shall be included in the lightning calculation document of each project (see section 3.4). In case that the civil requirements for LPZ 1 cannot be provided for the complete building, the measures described in chapter 7.3.2 have to be taken into account for I&C cabling as a minimum requirement. Beside the shielding measures described in this specification, e.g. metal cladding or reinforced concrete building, there are other special shielding measures to achieve LPZ 1 for a building or single building-sections. These special measures are to be defined and specified related to the requirement of project.
5.1.3
Lightning Protection Level (LPL),
The LPL (I to IV) determines the technical parameters (peak currents impulse charge, time parameters, steepness) in relation to occurrence probabilities of natural lightning strikes to be considered. LPL I considers lightning strikes with the highest parameters, LPL IV those with the lowest ones.
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The LPL’s results in certain requirements on the lightning protection system, which are summarized in so called protection classes, whereas class I represents the highest requirement and class IV the lowest one. The table below show the relationship between LPL, radius of rolling sphere, mesh width, distance between down/cross conductor and lightning current levels of external lightning protection system and foundation earthing systems. LPL
Radius of rolling sphere
Required maximum mesh width
I II III IV
20 m 30 m 45 m 60 m
5x5m 10 x 10 m 15 x 15 m 20 x 20 m
Required max distance between down/cross conductor 10 m 10 m 15 m 20 m
Maximum lightning current
Minimum lightning current
200 kA 150 kA 100 kA 100 kA
3 kA 5 kA 10 kA 16 kA
This table is a summary of several tables included in IEC 62305. A preliminary list of LPL for buildings/structures and areas of power plant is outlined below: Building GT enclosed structure ST enclosed structure Boiler Trasformer yard Electrical module Control building Water treatment plant building Warehouse building Air cooler condenser Emergency diesel module Black Start diesel module Cable trench Pipe rack and cable bridge Reinforced in-situ cable-ducts Underground cable ducts without continuous reinforcement Underground cable duct banks, shielded Note 1 ≡ In the case of new control building.
LPL II II III III II I (Note 1) III III III II II III III III III III
The final LPL for buildings/structures and areas shall be calculated. The list of LPL applicable to the projects shall be included in the lightning calculation document of each project (see section 3.4). The purpose of a lightning protection system (LPS) is to protect buildings from direct lightning strikes which can cause damage resulting in different types of losses. Four classes of LPS (I, II, III and IV) are defined in IEC 62305-1 based on the corresponding LPL. The performance of each class of LPS is given in IEC 62305-2. Project: Bolivia Combined Cycles Power Plants
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The LPS consists of external and internal LPS. The function of the external system is to intercept lightning strikes, to safely conduct and distribute lightning current to earth. The function of the internal systems is to prevent dangerous sparking inside the structure as this can cause extensive damage and fires. This is achieved by establishing equipotential bonding or maintaining a “separation distance” or in other words a sufficient electrical isolation between the components of the LPS and other electrically conductive elements.
5.2 EXTERNAL LIGHTNING PROTECTION 5.2.1
General
Assessment of lightning protection area can be carried out either by application of the Rolling Sphere Method or Protection Angle Method or other methods accepted by current standards.
5.2.2
Rolling Sphere Method
By use of the Rolling Sphere Method a sphere is virtually rolled around the buildings/structures. The area below the contact points of sphere to buildings and earth is protected against direct lightning strikes. The unprotected areas could be struck directly by lightning. The unprotected areas belonging to the buildings or structures need appropriate protection measures to ensure they comply with its assigned LPL. This method is described in the IEC 62305-3.
5.2.3
Protection Angle Method
By use of the Protection Angle Method the protected area is defined via the parameters of diagram according to figure A.1 of IEC 62305-3. Within the crown circle the area is protected against direct lightning strikes. The unprotected areas could be struck directly by lightning. The unprotected areas belonging to the buildings or structures need appropriate protection measures to ensure they comply with its assigned LPL. This method is described in the IEC 62305-3.
5.2.4
Other Methods
There are other methods to define the protected area against direct lightning strike, e.g. methods applied on outdoor air insulated switchyards or overhead lines. The general principle of these special methods is mainly derived from the Rolling Sphere Method.
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5.2.5 5.2.5.1
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Lightning Protection of Building/Structure General
The external lightning protection system of building/structure consists of air terminals, down conductors and cross conductors. The system is connected to the foundation earthing system in order to form a “Faraday Cage” around the complete building or structure to be protected. Metal frames and other metal structures integrated in the outer walls need to be connected to the lightning protection system. The minimum mesh width of the external lightning protection system is defined according to table of section 5.1.3. In order to achieve additional shielding effects and to reduce required separation distances the reinforcement must be conductively connected to the outer lightning protection system. 5.2.5.2
Minimum Design Requirements for Materials
The material for lightning conductors shall be steel, aluminium or copper. Depending on the use of material, the specified minimum cross section or thickness of material has to be applied according to IEC 62305, below there is a table with a summary of the standard data. Metal conductor material
Cross section of air terminal (mm2)
Cross section of down/cross conductor (mm2)
Thickness of metal sheet for cladding (mm)
Copper Aluminium Steel
50 70 50
50 70 50
0.5 0.65 0.5
5.2.5.3
Cross section/diameter of foundation or outdoor earth electrode or MEC (mm2/mm) 95/-/80/10
Cross section of equipotencial conductors (mm2) 16
Air Terminals
An air terminal network has to be installed on the roof. The maximum mesh width shall correspond with the LPL determined for the building/structure as per table of section 5.1.3. The following “natural” air terminals can be used if the minimum design requirements according to table of paragraph 5.2.5.2 are fulfilled: •
Steel beams of steel skeleton structure.
•
Metal cladding of roof.
It must be ensured that all connections of the “natural” air terminals are carried out by welding, clamping or screwing in order to provide a continuous conductive electrical connection. The connections must provide at least the minimum cross sections according to table of paragraph 5.2.5.2. Project: Bolivia Combined Cycles Power Plants
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Where necessary the mesh width shall be reduced significantly or amended further by other appropriate measures especially in building areas contenting sensitive electronic equipment in order to ensure significant shielding measures. The air terminations could be early streamer emission (ESE) air terminals. The installation of the Lightning Protection System using ESE air terminals must follow the relevant standards (NFC 17102, UNE 21186 or similar). 5.2.5.4
Down Conductors
The air terminals on the roof have to be interconnected by down conductors to the foundation earthing system or/and outdoor earthing system. Down conductors shall safely conduct the lightning current to earth. The number of and distance between down conductors depends on the defined LPL of the building and its associated mesh width as per table of section 5.1.3. The following “natural” down conductors can be used if the minimum design requirements according to table of section 5.2.5.2 are fulfilled: •
Steel columns of steel skeleton structure.
•
Metal cladding of wall.
•
Reinforcement bars in concrete columns with external connection links.
It must be ensured that all connections of the “natural” down conductors are carried out by welding, clamping or screwing in order to provide continuous conductivity. Where necessary the distance between down conductors shall be reduced significantly and/or amended further by other appropriate measures especially in building areas contenting sensitive electronic equipment in order to ensure significant shielding measures. The down conductors must be installed vertically in a straight line so that they represent the shortest most direct connection to earth. The required separation distance between down conductors and doors or windows or pipes shall be maintained. This separation shall be calculated in accordance with section 6.3 of IEC 62305-3. The earth entry rods or connectors which interconnect the down conductors to the ring earth electrode BERE must be protected against corrosion above and below the surface of the earth. 5.2.5.5
Cross Conductors
Horizontal conductors cross-connected with down conductors are required to provide the mesh width according to table of section 5.1.3 on the outer building walls. “Natural” cross-conductors can be used as specified under the item Down Conductors.
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5.2.6
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Metal Enclosed Power Control Centre (PCC)
The metal enclosed power control centre is a completely shielded metal enclosure and serves as a “Faraday Cage”. The enclosure is to be connected to the earthing system. This type of PCC is able to withstand direct lightning strikes and provides best possible shielding effects against electromagnetic fields.
5.2.7 5.2.7.1
Outdoor Cable Routes General
Outdoor cable routes provide different degrees of shielding against electromagnetic fields depending on their design and location. Distances between different voltages levels shall be executed as laid down in paragraph 7.5. The distances are valid for all cable routes. 5.2.7.2
Reinforced in-situ Concrete Cable Ducts
Ducts made of reinforced in-situ concrete shall have a continuously connected reinforcement. All expansion joints have to be bridged around the whole circumference of the duct. The reinforcement shall be connected to the earthing system of the buildings at the interface points at least in all 4 corners. Depending on the dimension of the reinforced in-situ concrete cable duct, the amount of foundation earth electrodes (FEE) has to be adapted. The distance between FEE shall be approx. 10m. At least in all 4 corners a FEE shall be applied as a minimum. The reinforcement of the in-situ concrete duct has to be connected to the FEE at distances of 2-3 m by twisted tying wires or clamping. The above measures described provide LPZ1. 5.2.7.3
Shielded Buried Cable Conduits
In order to provide a LPZ 1 screening effect for cable routes, buried plastic (PVC) conduits have to be encased by metal structures. Reinforcement mats with a maximum mesh width of 15cm x 15cm are a sufficient measure. The mats have to be overlapping and to be interconnected by twisted tie wires. At terminations to building structures, cable pulling pits or cable channels, conductive connections have to be provided. A bare stranded copper conductor (minimum cross section according to table of paragraph 5.2.5.2) has to be laid above the buried cable conduits in order to provide protection against direct lightning strikes to the cables or cable conduits. The conductor is laid approx. 0.6 m deep in earth. A protective angle of approx. 90° is applied. If necessary, several bare stranded copper conductors have to be installed for wider cable arrangements. The protection conductor has to be interconnected with the outdoor earthing system at crossings.
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5.2.7.4
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Cable Conduits Below Reinforced Foundations
Short PVC-conduits running completely below expanded, continuous foundations in close vicinity to high metal structures ensuring maximum dissipation of lightning currents (as for example applied between the Power control centre and the turbine hall) are assumed to be shielded sufficiently by the reinforcement and foundation earth electrodes embedded in the foundation plate. The lateral coverage of the foundation plate shall be at least 1.5m related to the outer cable conduits. The above measures described provide LPZ1. 5.2.7.5
Unshielded Buried Cable Conduits
A bare stranded copper conductor (minimum cross section according to table of paragraph 5.2.5.2) has to be laid above buried cable conduits or directly buried cables in order to provide protection against the direct lightning strikes to the cables only. The conductor is laid approx. 0.6 m deep in earth. A protective angle of approx. 90° is applied. If necessary, several bare stranded copper conductors have to be installed for wider cable arrangements. The protection conductor has to be interconnected with the outdoor earthing system at crossings. The above protection of buried cables provide LPZ 0B only. In case cables cannot be laid in a shielded environment they have to be treated as stated in section 7.3 at their transition to other LPZ’s. 5.2.7.6
Other Cable Ducts
Cable ducts without continuously connected reinforcement are typically made of •
pre-manufactured concrete elements (with or without reinforcement)
•
masoned elements
Such ducts provide LPZ 0B, the same LPZ as for buried cable conduits. Significant shielding effects (LPZ 1) for cables can be achieved by application of closed-metal covered cable trays or use of shielded cables, terminated to the earthing system at least at both ends. 5.2.7.7
Earth Buried Cables
Direct buried LV-cables apply only in exceptional cases for equipment, which is not directly relevant for the operation of the power plant or having significant safety relevance (lamp posts, camera system). Measures against lightning strikes shall follow the descriptions as stated in section 7.3. 5.2.7.8
Outdoor Cable Routes above Ground
Such cable routes are typically like: Project: Bolivia Combined Cycles Power Plants
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•
Cable trays or conduits
•
Sleeper ways (outdoor cable runs by means of trays)
•
Cable trays or conduits on pipe bridges
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In general such routes provide the same LPZ as the ambient area, which they are routed in. The cable route itself can provide a continuously enclosed shielding and therefore a LPZ 1 if at least one of the following requirements are fulfilled: •
Made of continuous metal conduit or metal cable trough with metal cover
•
Application of metal conduits or cable troughs connected to the earthing system at least at both ends.
•
Cable route consisting of a system of cable trays is encased by grid-like metal structures connected to the earthing system at least at both ends
•
Intermediate termination of the cable route to potential grading system
•
Use of shielded cables
5.3 INTERNAL LIGHTNING PROTECTION 5.3.1
General
The correct application of the external lightning protection measures will prevent high lightning currents from penetrating the buildings where the same could cause electro-magnetic interferences. However in order to provide maximum protection for the electric and especially electronic equipment, additional measures are taken into account inside the buildings. These measures are summarized in the following sub-sections. Special attention is to be given to all interface points between different LPZs.
5.3.2
Equipotential Bonding
The equipotential bonding system is the comprehensive term for all measures of external and internal lightning protection and the earthing system which are all interconnected and which all electric or I&C-components as well as other conductive parts and components are directly or indirectly terminated to. Thus a so called Common Bonding Network (CBN) is formed avoiding or at least reducing undesired potential differences. At the interface point between LPZ 0 and LPZ 1 all penetrating metal components have to be terminated to the equipotential bonding system. By this external lightning currents are prevented to enter the building due to direct conducting to earth.
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The following components are to be bonded at the entering point: •
Metal pipes without isolation barrier, e.g. gas, water, etc.
•
Metal ducts, e.g. exhaust ducts, HVAC ducts
•
Metal cable trays/risers and metal cable conduits
•
Cable shields
In case of buried, insulated pipes with cathodic protection the earthing connection has to be made by means of suitable isolating spark gaps.
5.3.3
Surge Protection Devices (SPD)
Due to the very high necessary efforts for design, installation as well as testing and maintenance the number of surge protection device shall be kept to a minimum. SPD’s shall be used only, when the required protection aims cannot be achieved by others measures such as avoiding transitions of LPZ’s by realisation of shielded cable routes (shielded duct banks or cable ducts) or application of shielded cables. The treatment of I&C cable is described under chapter 7.3.2. The treatment of LV-cables is described under chapter 7.3.3.
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6 EARTHING 6.1 GENERAL In the following section the basic earthing concept is explained. The earth electrodes shall be manufactured from pure and high conductivity hard drawn copper according to EN 13601.
6.2 OUTDOOR EARTHING SYSTEM 6.2.1
General
The outdoor earthing system comprises a power plant area wide meshed network (which is limited by the boundary fence of power plant) of buried earth electrodes (BEE), which are multiply interconnected and bonded to: •
buried earth ring electrodes around buildings (BERE)
•
foundation earth electrodes (FEE)
•
external lightning protection systems (via interconnection to BERE)
•
indoor earthing systems (component earthing via MEC or EC)
•
distant buildings or structures which need to be integrated into the power plant earthing and lightning protection measures
6.2.2
Meshed Buried Earth Electrodes (BEE)
The BEE is made of bare stranded copper conductor (minimum cross section according to table of paragraph 5.2.5.2) and shall have a mesh width of approx. 20 m x 20 m up to 40 m x 40 m. The BEE shall be laid in earth at a depth of approx. 0.6 m. Peripheral isolated buildings with electrical and electronic systems belonging to the power plant shall be connected to this earth grid. Special care has to be taken in case of interconnection of earthing systems of existing and new power plant units or buildings in order to avoid electrolytic corrosion problems. A reduced mesh size has to be considered in the direct vicinity of buildings and structures in order to ensure an optimized distribution of currents caused by lightning strikes.
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Herewith a maximum mesh-width of 10m and a mesh-length of 30m shall be realized whereas foundation earth electrodes and ring earth electrodes of neighboring buildings can be considered as substitutes for single meshes. The BEE of each plant shall be designed according to IEEE 80-2013.
6.2.3
Buried Earth Ring Electrode (BERE)
A ring earth electrode made of bare stranded copper conductor (minimum cross section according to table of paragraph 5.2.5.2) shall be laid in earth at a depth of approx. 0.6 m and at a distance of approx. 1 m around every building. The buildings down conductors have to be interconnected to the BERE. The earth entry connections must be protected according section 5.2.5.4. The distances of down conductor and interconnections are defined in table of section 5.1.3 according to the relevant LPL of the building. Due to the risk of corrosion additional anticorrosion measures should be taken. Material, configuration and minimum dimensions of the earth electrodes shall be according to table 7 of IEC62305-3.
6.2.4
Foundation Earth Electrode (FEE)
The foundation earth electrode (FEE) is formed by a mesh of solid round or solid flat steel bars. The necessary cross section of the FEE shall be selected according to table of paragraph 5.2.5.2. Secure interconnections of steel bars are carried out by welding or clamping. The required mesh width is defined in table of section 5.1.3 according to the relevant LPL of the building. The reinforcement of foundation has to be connected to the FEE at distances of approx. 2 - 3 m by twisted tying wires or clamping. Expansion joints in the base plate of structure have to be conductively bridged with the selected cross section of table of section 5.2.6.
6.2.5
Outdoor Earthing Terminal
Outdoor earthing terminals are used to interconnect the FEE with BERE, BEE, down and cross conductors. The amount of outdoor earthing terminals shall comply with the minimum number of down conductors as specified in table of section 5.1.3.
6.3 INDOOR EARTHING SYSTEM 6.3.1
General
The indoor earthing system includes all earthing measures inside buildings, which prevent dangerous potentials on touchable metallic surfaces. Additionally, the indoor earthing system is an integral part of the EMC measures. Project: Bolivia Combined Cycles Power Plants
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The indoor earthing system consists of main earthing conductors (MEC), the earthing conductors (EC), additional potential grading conductors and all metallic parts conductively connected forming the Common Bonding Network (CBN).
6.3.2
Main Earthing Conductors
The MEC consist of bare stranded copper conductors (minimum cross section according to table of section 5.2.5.2). They run throughout the building and provide definite earth potential connection points. Each MEC is to be connected to the outdoor earthing system in minimum at two different locations. Intermediate terminations to steel parts connected to the foundation and or outdoor earthing system improves the function of the MEC significantly.
6.3.3
Earthing Conductors
The EC is a link conductor connected to the MEC made of bare stranded copper. The EC provides definite earthing connections to metal components and equipment. The EC may alternatively be connected to earth potential at BEE or BERE terminal points. Protective earth conductor (PE) or protective earth and neutral conductor (PEN) in power cables serve as the EC.
6.3.4
Additional Potential Grading Conductors
In order to avoid potential differences between metal parts potential grading conductors are installed. Such conductors shall have at least 16mm² copper fulfilling the requirements as a conductor for lightning protection bonding.
6.3.5
Steel Columns and Metal Base-frames
Steel columns and metal frames shall have as minimum one visible connection to the earthing system. The type of construction shall ensure electrical continuity. Embedded base-frames for I&C and electrical cubicles shall be directly connected to the foundation earthing system or to the floor reinforcement. At least two interconnections at opposite sides have to be applied per baseframe structure.
6.3.6
Indoor Earthing Terminal
Indoor earthing terminals are used to interconnect the FEE with BERE, MEC or EC. They shall be provided at least in each corner of building or structure or room containing equipment to be earthed. The distance between
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each indoor earthing terminal shall not exceed 15m (also in vertical direction in case of structures with more floors e.g. boiler). Attention has to be paid, that such earthing terminals are realized in all locations, where electrical or I&Cequipment are arranged and required to be terminated to the earthing system by shortest possible connections.
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7 MEASURES AGAINST ELECTROMAGNETIC INTERFERENCES 7.1 GENERAL Electromagnetic fields as they are caused especially by switching actions or strong lightning strikes could disturb the operation of the plant by maloperations or other faulty signals or even damage electrical and electronic devices. Such effects could be caused by: •
Conducted and induced surges transmitted to equipment via connected cables
•
Effects of radiated electromagnetic fields directly into the devices itself
Protection measures to minimize the risks of such effects have to be envisaged.
7.2 ELECTRICAL AND ELECTRONIC DEVICES Electrical and electronic devices have to be protected against direct lightning strikes (arrangement in LPZ0B). Preferably electronic devices shall be arranged in buildings or structures with appropriate shielding effects (buildings with continuously connected metal roofs and wall claddings). In general all devices have to be selected in terms of their interference resistivity related to the LPZ (0B or 1) they are arranged in. The following measures are part of the overall electromagnetic compatibility (EMC) measures of the power plant.
7.3 OUTDOOR LAID CABLES 7.3.1
General
For LPZ definitions refer to chapter 5.1.2. Cable routes shall be planned in such a way, that cables are laid in areas not less than LPZ 0B in order exclude direct lightning strikes. In order to avoid transition of different LPZ’s cable routes shall be designed to ensure significant shielding effects. For measures to achieve LPZ 1 for cable laying in outdoor areas, see chapter 5.2.7. In any case the overall design of cable routes shall be done in such a way, that partial lightning currents running along the cable routes are as low as possible. This can be achieved by for example:
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a dense meshed grid of buried earth conductors around buildings being subject to lightning strikes for best current dissipation
•
an earthing system (foundation- and buried-earthing system) ensuring best possible conduction of lightning currents to earth
•
a dense meshed earthing grid for best-possible compensation of potential differences
•
connection of other conductive service lines to the potential grading systems at the entrance to buildings or structures
•
separated LP-posts for directed conduction of lightning currents
However, certain measures for the following cables have to be realized:
7.3.2
Instrumentation and Control (I&C) Cables
The term I&C cable refers to the following cable types with maximum operation voltage U < 60V: •
I&C cables
•
Communication cables (telephone, fire detection, CCTV, LAN, etc.)
•
Control cables
I&C-cables including the devices they are terminated to are endangered by the following instances: •
Direct strikes to cables causing thermal damages
•
Galvanic (direct) coupling effects leading to overvoltages
•
Inductive coupling effects causing overvoltages
•
Malfunctions caused by coupling effects
In order to avoid these effects a number of measures are determined in the power plant: •
Cable routes are preferably planned in such a way, that all I&C-cables are laid in areas providing LPZ 1.
•
Cable routes are planned in such a way, that all I&C-cables are laid in areas not less than LPZ 0B
•
I&C-cables are generally shielded
•
I&C-cables laid at least partly in LPZ 0B are equipped with an additional copper braid shield (> 80% covering). In case of I&C cables are laid entirely within the LPZ 1 a foil shield is sufficient
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Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
•
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P.G.G.
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32/88
In case I&C-cables, which cannot be equipped with braided shield and run through LPZ 0B areas SPD must be installed
•
The foil screen has to be connected to earth within the terminated equipment at both ends (e.g. via shielding bus of cubicle or direct connection to the earthed enclosure)
•
The braided shield has to be connected at least twice to earth, the connection by appropriate brackets shall encompass the shield circumference as much as possible
•
The braided shield has to be connected to earth close to the entrance to a higher LPZ, the connection by appropriate brackets shall encompass the shield circumference as much as possible
•
Cables carrying significant partial lightning currents must be laid on separated cable routes
•
If the cable shield cannot be bonded at the sensor, e.g. the sensor has a plastic enclosure, the cable shield shall be only bonded at the next terminal point close by, usually in the sub-distribution board. Alternatively the sensor can be equipped with EMC-cable-glands with terminal for earthing purposes.
•
Shields of intrinsically safe cables have to be earthed at least once. Shields of intrinsically safe cables shall be connected to earth in the non Ex-zone only. In the Ex-zone these shields remain unearthed. IEC 60079-14, chapters 12.2.2 and 9.6.3 have to be followed.
Power supply cables with operating voltage U< 60 V are laid in LPZ 1-environment and do not need a shield.
7.3.3
Power Cables
The term power cable represents the following cable types with operating voltage U ≥ 60V: •
AC and DC low voltage cables
•
Control cables
•
Medium voltage cables
•
High voltage cables
LV-power- and control-cables including the devices they are terminated to are endangered by the following instances caused by lightning strikes: •
Direct strikes to cables causing thermal damages
•
Galvanic (direct) coupling effects
•
Inductive coupling effects
Project: Bolivia Combined Cycles Power Plants
Projectcode
Document Title:
BO1001 BO1000 BO1002 Logo Originator
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
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P.G.G.
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These effects could cause unpermitted high overvoltage, which could lead to damages to cables, terminated equipment and sparking endangering equipment and personnel in explosive areas. In order to avoid these effects a number of measures are determined in the power plant: •
Interconnection of several LPZ of one type Cable routes are preferably realized in such a way, that all Power-cables are laid over there whole lengths in areas providing LPZ 1 so that there are no transitions of Lightning Protection Zones:
•
If Power-cables cannot be laid in LPZ 1 area entirely the following measures shall apply: o
Shielded cables Power cables, which cross LPZ 0B and enter LPZ 1 shall be equipped with a copper shield or by means of steel wire armouring. The shield of power cable has to be bonded to the earthing system in close vicinity of the interface point to the higher LPZ or directly to the shielding equipment located in 0B-area. The bonding connection shall encompass the shield circumference as much as possible. Sufficient shield or conductor cross section for equipotential bonding along cable route has to be ensured (in total 16 mm2 copper equivalent).
o
Application of Surge protection devices Alternatively the cable can be equipped with SPD’s at the interface point to the higher LPZ 1 terminal point or directly in the electrical or electronic device the cable is terminated to.
•
Equipment and/or cables in zone 0A Electrical and I&C equipment have generally to be located in 0B-areas. However, in case of systems or equipment not being directly relevant for the undisturbed operation of the power plant or having not significant safety relevance (lamp posts, camera system) exceptions are permitted. In case, that power cables are crossing LPZ 0A and enter LPZ 1 the same shall be shielded with a copper shield or by means of steel wire armouring. Sufficient shield or conductor cross section for equipotential bonding along cable route has to be ensured (in total 25 mm2 copper equivalent). The shield of power cables has to be bonded to the earthing system in close vicinity of the interface point to the higher LPZ as well as the equipment the cable is connected to. Beside that SPD’s have to be installed in the system source (e.g. lighting distribution boards) near zone transfer.
Project: Bolivia Combined Cycles Power Plants
Projectcode
Document Title:
BO1001 BO1000 BO1002 Logo Originator
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
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7.4 I&C POWER SUPPLY REFERENCE CONDUCTOR (M) The reference conductor of 24V DC power supply shall be solidly earthed at the in-feed side of I&C cubicles by a direct and shortest as possible connection to the cubicle’s base-frame. The reference conductors must not be earthed at the power supply side, e.g. in DC/DC converters. The cubicle base-frames must be connected to the earthing system.
7.5 SEPARATION OF CABLES All cables are assigned to levels according to their operating voltage: Level 1 2 3 4
Description Control and I&C cables Low voltage power and control cables Not used Medium voltage cables
Maximum Operating Voltage U < 60 V 60 V ≤ U ≤ 1 kV U > 1 kV
The level 1 will be installed the upper one and the level 4 will be the lower one. The minimum vertical separation distance between levels of cable trays will be 200 mm from top to bottom. The minimum separation distances for cable conduit arrangements will be 250mm between centers of the conduits. The given minimum separation distances are applicable for direct buried cables as well as for individual cable arrangements. The separation distances can be reduced if the parallel cable routes of different levels are short. The following table defines reduced separation distances in relation to the parallel run of cables. Reduction of minimum distances between cables of different voltage levels Parallel cable run: Voltage levels: Minimum distance: 0…5m Level 1 and level 2 0 0…5m Level 1 and level 4 0 5 … 20 m Level 1 and level 2 ≥ 0.1 m 5 … 20 m Level 1 and level 4 ≥ 0.25 m
7.6 SEPARATION DISTANCE BETWEEN CABLE ROUTES AND LPS In general, the minimum separation distances of cables to air terminals, down conductors and cross conductors shall be considered:
Project: Bolivia Combined Cycles Power Plants
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Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Building height h < 20 m h > 20 m
Separation distance to the down conductors at the walls LPL I/II LPL III 40 cm 20 cm 60 cm 40 cm
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Separation distance to the air terminals LPL I/II LPL III 60 cm 40 cm 80 cm 60 cm
If the following building components are used as natural parts of the lightning protection system separation distances do not need to be considered inside buildings/structures: •
Conductively interconnected metal claddings
•
Embedded, bonded steel bars, which the reinforcement is terminated to
Project: Bolivia Combined Cycles Power Plants
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BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
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BO1001-00BAU-EEC102-448220640
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8 INSPECTIONS AND TESTS 8.1 INSPECTIONS All the stages of design, material procurement, manufacture, construction, trials and tests, transport, etc. included in this specification shall be subject to inspection by the Buyer or by its representatives. The Buyer shall have the right to visit the Supplier’s premises in order to verify compliance with the requirements figuring in this specification, and mainly in the documents required by the specification but not requested for approval.
8.2 CERTIFICATES Certificates of each equipment supplied must be sent.
Project: Bolivia Combined Cycles Power Plants
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Document Title:
Earthing and Lightning Protection Technical Specification
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9 QUALITY REQUIREMENTS The product covered by this specification shall comply with the requirements figuring in said specification and with those imposed by the operating conditions. Furthermore, it shall also comply with international best practice of recognized prestige. For this purpose, the VENDOR shall apply and document a quality system certified as per ISO 9001. The scope of this system shall cover all the products, systems and services connected with the contract and, consequently, the VENDOR shall be responsible of its application throughout the chain of subcontractors. Furthermore, the VENDOR shall prepare and deliver an Inspection Points Program for the Supply, a Manufacture and Quality Procedure and a Final Quality Control Report. Purchaser reserves the right to verify and assess the application of the quality system defined, including that of its subcontractors, at any time during the life of the contract. This right extends to the final customer and their authorized representatives. Should there be any deviation in the application of the quality system that entails any doubt or evidence regarding product quality, the Purchaser reserves the right to carry out verifications or tests additional to those initially scheduled either at the VENDOR’s premises or at those of its subcontractors. Acceptance by the Purchaser of any document or activity associated with the product does not exempt the VENDOR from its obligation to supply and install a product fully compliant with the specification and the service conditions and requirements.
9.1 QUALITY CONTROL PLAN Within a period not exceeding three (3) weeks from the NTP, the Contractor shall submit to the Purchaser, the Quality Control Plan which is applicable to the equipment manufacture. This program shall include the detailed testings and their schedule. Purchaser's inspectors and/or representatives shall verify the progress of the work by means of visits to Contractor's premises. They shall verify that work is on schedule and that material and/or equipment is being manufactured in accordance with the technical specifications, codes, standards and procedures detailed on the purchase order and attachments thereto. After contract award, the detailed list of tests must form the basis of an inspection test program from which Purchaser will select tests to be witnessed by Purchaser's representatives. Tests must be recorded by issuing tests certificates stating all significant test parameters. Test certificates are to be dispatched promptly to Purchaser after test completion. Project: Bolivia Combined Cycles Power Plants
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BO1001 BO1000 BO1002 Logo Originator
Earthing and Lightning Protection Technical Specification
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Witness and approval of tests by Purchaser's representatives will not relieve Contractor of any contractual liabilities or responsibilities.
9.2 INFORMATION TO BE PROVIDED WITH THE OFFER The VENDOR shall include the following information in its offer: •
ISO 9001 certificate of its quality system
•
List of procedures of its quality system
•
Design review plan
•
Procedure for handling design changes and Buyer’s participation
•
Procedure for handling non conformities and Buyer’s participation
•
Validation status of the product parts, components and equipment. Plans and provisions for those that have not been validated as suitable for this specification and for the operation and service requirements.
•
Standard quality plan. Typical quality plan for this product. It shall have the usual format of the inspection and test plans and include all the product equipment. It shall identify its parts, components and the whole equipment.
•
Any provision for third party inspections must be included.
9.3 INFORMATION AFTER THE CONTRACT The documentation mentioned in point 10 shall be submitted for approval. Regarding the quality documentation, the following actions, documentation and clarifications shall be included: •
Design review plan The Buyer shall decide on its participation in the plan.
•
Design changes All major changes to documents already approved in the design reviews and to those issued for manufacture/construction shall be subject to the approval of Buyer and shall not be processed without its approval. Minor changes shall be reported at the time of their approval by the VENDOR. -
Major changes: changes that may affect contractual requirements or that may significantly affect the form, function, interface with other equipment or structures, or the integrity of same.
Project: Bolivia Combined Cycles Power Plants
Projectcode
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BO1001 BO1000 BO1002 Logo Originator
Earthing and Lightning Protection Technical Specification
Document Number
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Minor changes: those that are not classified as major changes.
Non conformities The list of non conformities of the VENDOR and their subcontractors shall be monthly submitted to the Buyer. All the proposals to settle major non conformities shall be subject to the approval of Buyer. No settlement shall be applied until it has been approved by the Buyer. The definition of major non conformities is as defined in the previous point for design changes.
•
Product validation The VENDOR shall demonstrate that all main, auxiliary and control equipment is qualified for operation under the requirements and service conditions figuring in this specification. Means such as type qualification, design verification and/or review, validation tests and experience shall be used at the VENDOR’s discretion.
•
Quality control plan The quality control plan shall include all the activities necessary to ensure correct processing of the product. This plan shall have at least the format of an inspection points program (PPI) in order to be accepted. This plan shall be submitted to Buyer for approval. It shall cover all product elements, i.e. parts, components, equipment (including standardized elements), and the overall product up to the level required to include everything that affects its operation and life. The plan shall contain all processing stages, from material procurement up to testing. The plan shall include all the activities, operations and verifications carried out during product processing. The plan shall identify the following: sequence of operations, applicable procedures, participants and their control activity (from the raw material subcontractor up to the VENDOR), type of verification/inspection, sampling system, when applicable, and type of records to be issued. Whenever a Notified Body or third party participates in the activities, this shall be specified in the plan. The Buyer shall include in this quality control plan both its inspection points and those of the final customer. The VENDOR shall give advance notice to the Buyer of the date when the inspections are going to be performed.
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
•
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Product documentation The documentation to be delivered during the contract has been defined in point 10. Trial and test certificates and reports for materials and equipment, process and welder’s qualification, NDTs and tests shall be as per type 3.1 of EN 10204. Lower-level certificates shall only be applied to standardized minor parts.
9.4 INSPECTION AND TEST PLAN (ITP) The Supplier shall submit to the approval of the Purchaser an Inspection and Test Plan that explicitly and correlatively develops each and every one of the phases of the procurement, manufacture and testing, and preparation for shipment. The inspection plan to be carried out by the supplier shall be indicated. For each point the Supplier shall indicate the internal procedure that is applicable. He shall also indicate whether a report or protocol will be generated for each point, or whether other associated documentation will be provided (quality certificates, reception reports, etc.). The Purchaser shall select the points on this programme which they or their representatives shall witness. During the inspection visits, the Purchaser reserves the right to review applicable documentation that has not been presented for his approval (reception procedures, manufacturing procedures, etc.). The Inspection and Test Plan (ITP) shall comprise a minimum of the following sections in which the following information shall be given: •
Materials inspection. Main materials and components: inspection upon reception of materials to be used in manufacture, with indication of those that will require quality certificates.
•
Inspection of manufacturing. List of the main in-process inspection points.
•
Examinations and tests. A list of all the tests indicated in this specification, with reference to each associated procedure that specifies the acceptance criteria for the test in question.
•
Protection, cleaning, painting, labelling and delivery. Final documentation. A statement of the monitoring or inspection of these activities setting out the procedures to be applied and including a revision point for the final documentation dossier and an issue point for the Delivery Note.
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
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10 PROJECT CONTROL AND DOCUMENTATION 10.1 GENERAL REQUIREMENTS The three (3) Thermoelectric Power Plants follow an identification system based on the KKS code (power plants coding system) issued by an expert committee from VGB. Every item (equipment, instruments, lines, cables, valves, etc.) shall be identified in accordance with the application guide of the KKS identification system for the project. All the identification codes of the components to be supplied shall be identified by the VENDOR in accordance with the criteria defined in the KKS system application guide: BO1001-11620-AEC102-447981238 APPLICATION GUIDE OF THE KKS IDENTIFICATION SYSTEM, and shall be submitted to BUYER for comments. The Contractor shall submit monthly reports of the activities carried out during that period. These reports shall identify any deviation from the project schedule. They shall include a planning of the activities to be carried out in the following period and an action plan to avoid deviations and settle pending items. Meetings may be held at the VENDOR’s premises in order to confirm the quality and progress of the project. These meetings shall analyze design development, material preparation, manufacture, procedures, tests, etc. The date and place of these meetings shall be included in the project contractual schedule; nevertheless, the Buyer reserves the right to hold additional meetings giving advance notice to the VENDOR. The acceptance or approval by the Buyer of any VENDOR’s document, process or report shall not release the VENDOR from its contractual obligations.
10.2 DOCUMENTATION REQUIREMENTS If the documents listed are not submitted to the Buyer it shall be considered that the scope of supply has not been fulfilled. All the documentation between the VENDOR and the Buyer shall be exchanged by means of a software tool that operates in a safe web environment managed by the Buyer. Not fulfilling this requirement shall be considered as a non compliance of the scope of supply. The coding, format and management of project documentation shall be carried out in accordance with the guides and procedures to be provided by the Buyer after the award. VENDOR shall submit specific documentation package per each plant.
Project: Bolivia Combined Cycles Power Plants
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Document Title:
Earthing and Lightning Protection Technical Specification
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All the documentation, manuals, diagrams, training courses, etc., shall be written in English. At least O&M Manuals and training courses shall be also submitted in Spanish. Other documents that may be required in Spanish language shall be specified by Buyer before contract awarding The documents shall be prepared in MS-Office 2000 or compatible program. The drawings and diagrams shall be made in AUTOCAD format. When preparing the documents, they shall be printed in Acrobat .pdf format, version 7 or better. By defect, the documentation shall be exchanged in a “.pdf” format of sufficient density, unless in those cases when the executable file is requested. Nevertheless, after the project documentation has been approved, including the as-built documentation, all the documentation generated by the VENDOR shall be provided in executable format. Furthermore, once approved, two (2) sets of the final dossiers shall be provided on paper and organized into folders for each one of the three (3) Power Plants, in accordance with the requirements specified by the Buyer in the corresponding procedure. Also a CD with an electronic copy shall be provided for each Power Plant. Both printed copies as well as the CDs shall be sent by the VENDOR to Bolivia. Specific shipping addresses will be provided by Buyer after contract award. The format and folding of drawings and/or documents shall comply with DIN standards. The smallest allowable format for drawings and diagrams shall be A3 (A4 for documents) as per UNE 1027. All the documents shall be prepared using the formats supplied to the winning bidder at the kick-off meeting. These documents shall contain at least the identification of the project, date and revision number, document change control table, reference or applicable documents and signatures of the author and the approver. The International System of Units shall be used, except in the case of units corresponding to pipe size and diameter, which shall comply with ANSI/ASME. The approval by Buyer of drawings or other document revisions by the VENDOR shall not release the latter from its obligation to comply with all the requirements figuring in the Purchase Order. After receiving a drawing or other document, the VENDOR shall identify the revision by means of a digit in the corresponding box and specify the reason for the request for modification. All the changes in documents and drawings shall be clearly marked up in subsequent revisions. The VENDOR shall not be allowed to make changes in previously approved drawings or other documents unless expressly authorized in writing by the Buyer. The Buyer shall have two (2) working weeks to return to the VENDOR the first edition with comments of the drawings or documents. Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
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VENDOR shall have a maximum of two (2) working weeks to return to the Buyer the revised documents or drawings according to Buyer’s comments, except those duly justified and agreed between Buyer and VENDOR within these two (2) weeks. VENDOR shall submit a new revision of the documents/drawings until Buyer’s acceptance.
10.3 DOCUMENTS TO BE PROVIDED WITH THE OFFER In addition to the quality documents required in point 9.2, the bidder shall also include in its offer a detailed description of the installation proposed. This shall include the following: •
Equipment description and characteristics.
•
List of components.
•
Alternatives that it may deem of interest.
•
List of service, material and equipment subcontractors.
•
Information necessary to understand the operation of the equipment.
•
Exceptions to the specifications with detailed justification.
•
List of references.
•
Completed datasheets.
•
Layout drawing showing general arrangement of the complete scope of supply.
•
General dimension drawing.
•
Cross-sectional drawing with bill of materials.
•
List of electrical consumers showing installed and consumed power.
•
Single-line diagrams.
•
General layout of boards and junction boxes.
•
Description of the control and wiring system.
•
Safety level (operation and redundancy).
•
Auxiliary services requirements.
•
Guarantees.
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
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Design standards and list of tests that the VENDOR plans to carry out on each of the items of equipment included in the supply, indicating the standards followed for the tests.
•
Time schedule including at least the following milestones: delivery of documentation, manufacture, shop erection and tests, transport, testing and commissioning.
•
Complete list of recommended spares, auxiliary items and test equipment quoted. This list shall include unit prices and clearly separate the spares foreseen for the commissioning period and those recommended for two years’ operation.
•
List of accessories and special tools.
•
General quality control plan including Inspection Points Program (IPP).
•
List of deviations and/or exclusions. It shall be understood that everything not explicitly included in this list shall be performed in accordance with this specification.
•
Equipment type test certificates.
10.4 DOCUMENTS TO BE PROVIDED AFTER ORDER ACCEPTANCE The VENDOR shall submit the documents listed in Attachment A, according to the dates stated in that document. These documents shall include all the information necessary for project interfaces, input data, contract followup and operation and maintenance. The specific project document list will be provided after acceptance of the Purchase Order has been given and no later than the defined dates. Any changes to the documents shall be controlled during the development of the project. Changes may originate from design modifications, non-conformance, as-built deviation, etc. All changes approved by the Purchaser shall be incorporated in order to maintain all project documents updated. The final edition of all documents in the "as built" edition shall be incorporated into a Final Dossier. The Final Dossiers shall be submitted by the VENDOR. Each group of documents of the final Dossiers will be identified by a first divider sheet including a section number and pagination. Dividers will have the section numbers at different levels to facilitate location.
10.5 FINAL DOSSIERS Specific procedure for the elaboration of the final dossier shall be submitted by the Buyer. A preliminary distribution, to be confirmed by the Buyer after contract award, shall be the following.
Project: Bolivia Combined Cycles Power Plants
Projectcode
Document Title:
BO1001 BO1000 BO1002 Logo Originator
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
10.5.1 Documents to be included in the technical dossier 1
List of documents
2
List of assemblies forming the equipment (piping, valves, filters, etc.)
3
Equipment technical characteristics (risk analysis, calculations…)
4
Mechanical diagrams (P&IDs, Isometrics…)
5
Electrical diagrams (single-line diagrams…)
6
Instrumentation diagrams (functional diagrams, signal database…)
7
Bill of materials (if not included on the drawings) and other lists
8
Technical specifications or reports
9
Material purchase specifications
10
Datasheets
11
Mechanical drawings
12
Civil works and structural drawings
13
Electrical drawings
14
Instrumentation drawings
15
Manufacture, paint, packaging and shipping procedures
16
Functional descriptions of the various systems
17
Operation, conservation and maintenance manuals
10.5.2 Documents to be included in the manufacturing dossier 1
Declaration of Conformity (against the Purchase Order)
2
CE Declaration of Conformity
3
List of Non Conformities and Non Conformity report (closed)
4
General documents (lists, drawings…)
5
Inspection Points Programs (IPP) (completed)
6
Welding book
6.1
Welding procedures
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Projectcode
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Earthing and Lightning Protection Technical Specification
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6.2
Welding procedure qualification record
6.3
Welder’s qualification record
7
Procedures
7.1
Manufacturing procedures (forming, paint, heat treatments, etc.)
7.2
Test procedures
7.3
Inspection procedures
8
Material certificates and component certificates
9
Equipment calibration certificates
10
Reports / Certificates:
10.1
Certificates / Non Destructive Testing
10.2
Certificates / Specific product reports (vibrations, noise, etc.)
10.3
Certificates / Reports
10.3.1 Structural tests (hydrostatic test) 10.3.2 Operational tests 10.4
NDT personnel qualification certificates
11
Specific documentation for pressure vessels (if applicable)
12
Equipment approval certificates when required
10.5.3 Documents to be included in the erection dossiers 1
Erection procedure + specific procedures
2
Test procedure
3
Completed and signed IPPs
4
Topographic protocols
5
Welding
5.1
Welding procedures (PQR, WPS)
5.2
List of welders and welders’ qualification
5.3
Welding maps
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Projectcode
Document Title:
BO1001 BO1000 BO1002 Logo Originator
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
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6
Testing
6.1
NDT / Reports
6.2
Other tests (paint, bolt torque, etc.)
7
Tests
7.1
Hydrostatic tests, operating tests, etc.
8
Material control (Materials managed by the site, not processed by the manufacturing or purchasing departments)
8.1
Material certificates
8.2
Traceability of materials
8.3
Material testing
9
Technical instructions / Datasheets
10
Measuring instruments and calibration certificates
11
Non conformities / Punch list
12
Auxiliary records required in the Dossier (letters, project modifications, repairs, etc.)
13
As-built drawings
10.5.4 Documents to be included in the commissioning dossier 1
Engineering documentation
1.1
System description
1.2
P&IDs, single-line diagrams
1.3
Logic
1.4
Control loops
1.5
Lists (Lines, supports, valves, equipment, instruments...)
1.6
Electrical diagrams
1.7
Reference documentation
2
Commissioning documentation
2.1
Commissioning procedure
Project: Bolivia Combined Cycles Power Plants
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Earthing and Lightning Protection Technical Specification
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2.2
Functional tests procedure
3
Protocols
3.1
Electrical protocols
3.1.1
Rotating equipment
3.1.2
Static equipment
3.1.3
Megger test protocol (power cables)
3.2
Instrumentation and Control protocols
3.2.1
Instruments
3.2.2
Control loops
3.2.3
Logic
3.3
Mechanical Protocols
3.3.1
Cleaning
3.3.2
Equipment
3.3.3
Alignment
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Projectcode
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Document Title:
Earthing and Lightning Protection Technical Specification
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ATTACHMENT A DOCUMENTS TO BE PROVIDED AFTER ORDER ACCEPTANCE
Project: Bolivia Combined Cycles Power Plants
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BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Description
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J.J.R.
P.G.G.
Revision
Page Number
-
50/88
For information and approval
Final documents for filling purposes
No. copies
Date (1) (weeks)
No. copies
Date (2) (weeks)
1
Monthly progress report.
(3)
Monthly
2
List of documentation, including foreseen date of issue.
(3)
2
(4)
2
3
Detailed schedule of project activities.
(3)
2
(4)
2
4
Calculations.
(3)
4
(4)
2
5
List of systems, I/O list and cable list.
(3)
4
(4)
2
(3)
2
(4)
2
(3)
8
(4)
2
6
7
Datasheets of equipment, instruments and other components. Final list of electrical apparatus and devices and auxiliary mechanical devices, including designation, make and type of each of them, catalogues and corresponding technical information.
8
Installation and erection instructions.
(3)
(6)
(4)
(6)
9
Detailed quality control plan and ITP (Inspection and Test Plan) showing the dates for said controls.
(3)
4
(4)
2
10
Protection and paint procedures.
(3)
4
(4)
2
11
Test procedures (operation, performance, etc.).
(3)
6
(4)
2
12
Commissioning procedures.
(3)
(6)
(4)
2
13
List of consumables and spares for commissioning.
(3)
8
(4)
2
14
Priced list of spares for two (2) years warranty period.
15
List of special tools and test equipment.
(3)
4
(4)
2
16
Material certificates and protocols of the tests carried out.
(3)
16
(4)
2
17
Final instructions for start-up.
(3)
8
(4)
2
Project: Bolivia Combined Cycles Power Plants
4
Projectcode
Document Title:
BO1001 BO1000 BO1002
Earthing and Lightning Protection Technical Specification
Logo Originator
Document Number
BO1001-00BAU-EEC102-448220640
Description
Prep. By
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P.G.G.
Revision
Page Number
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51/88
For information and approval
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No. copies
Date (1) (weeks)
No. copies
Date (2) (weeks)
18
Non conformities.
(3)
(7)
(4)
2
19
Manufacture and progress reports.
(3)
Weekly
(4)
2
20
Identification plate facsimile (if applicable).
(3)
8
(4)
2
21
Manufacture and test certificates.
(3)
(7)
(4)
2
22
Certificates of compliance with the codes.
(3)
2
(4)
2
23
Training course documentation.
(3)
16
(4)
2
24
Operation and maintenance manual.
(3)
(6)
(4)
2
25
Official documents and certificates: certificate of conformity, other documentation necessary to obtain official permits.
(3)
2
(4)
2
26
As-built documentation.
(3)
-
(4)
2
27
Equipment descriptions and subsystems specifications.
(3)
2
(4)
2
(3)
2
(4)
2
(3)
2
(4)
2
28 29
Final assembly drawings, cross-section (including list of elements and materials). General list of components of the complete supply for approval, indicating the manufacturer, type and specifications of each one.
30
Welding qualification and welding procedures.
(3)
2
(4)
2
31
Manufacturing procedures.
(3)
2
(4)
2
32
Repair procedures.
(3)
8
(4)
2
33
External cleaning and coating procedures.
(3)
4
(4)
2
34
Heat treatment procedures.
(3)
2
(4)
2
35
NDT procedures.
(3)
-
(4)
2
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Description
Prep. By
Checked by
J.J.R.
P.G.G.
Revision
Page Number
-
52/88
For information and approval
Final documents for filling purposes
No. copies
Date (1) (weeks)
No. copies
Date (2) (weeks)
36
Final instructions for commissioning.
(3)
(4)
(4)
2
37
Erection control and adjustment sheets.
(7)
(4)
(4)
2
38
Report of repairs, deviations and defects.
(7)
(4)
(4)
2
39
Final dossiers.
(3)
(8)
(5)
Notes: (1) Weeks after the date of the contract. (2) Weeks after the document attains RCC status (Reviewed with comments). The document shall be reviewed until it attains RSC status (Reviewed without comments). (3) Only electronic file required. (4) After the RSC status is attained (Reviewed without comments), the electronic file in “.pdf” and executable format is required. (5) 2 hard copies organized into folders and 1 copy on CD are required with the electronic files in “.pdf” and executable format. (6) Two weeks before the equipment is shipped to site. (7) They shall be submitted as it occurs. (8) Before the equipment is shipped to site.
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
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P.G.G.
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ATTACHMENT B EPC PART 4-4 OOCC SUR PRNF. DOC PAGE 22 GROUNDING GRID
Project: Bolivia Combined Cycles Power Plants
Projectcode
BO1001 BO1000 BO1002 Logo Originator
Document Title:
Earthing and Lightning Protection Technical Specification
Document Number
BO1001-00BAU-EEC102-448220640
Prep. By
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P.G.G.
Revision
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ATTACHMENT C EARTHING TECHNICAL REQUIREMENTS FOR GAS TURBINES
Project: Bolivia Combined Cycles Power Plants
This document is issued in Pulse.
Technical Requirements
We reserve all rights in this document and in the information contained therein. Reproduction, use or disclosure to third Parties without express authority is strictly forbidden. © Siemens Industrial Turbomachinery AB
Electrical Installation Gas Turbines
Earthing
Project
Template No. &EC101_1 rev-
Based on Author
SIT / RAE / GD
Appr.
Thomas Wiktorsson
Doc. kind Title
Technical Requirements Earthing
2008-07-04
Electrical Installation Gas Turbines
2008-07-07 Doc . des.
/EEC 101
Resp. dept.
des.
RAE
Document number
Siemens Industrial Turbomachinery
Ref.
1CS77950
Order no. Lang.
en
Rev. ind. Sheet
R
No. of sh.
1 31
CONTENTS 1. General....................................................................................................... 4 1.1 1.2 1.3
1.4
Introduction ........................................................................................................ 4 Definitions and explanations ............................................................................. 5 Description of the different types of earthing systems .................................... 5 1.3.1 External Grid in ground .......................................................................... 5 1.3.2 Equipotential bonding system –safety earthing ...................................... 5 1.3.3 Protective Earth, PE, system –safety earthing ........................................ 6 1.3.4 Instrument Earth IE, SC –functional earthing......................................... 6 1.3.5 Intrinsically Safe (IS) –functional earthing............................................. 6 1.3.6 Lightning Protection System................................................................... 6 Suppliers responsibility ..................................................................................... 8 1.4.1 Civil contractor ....................................................................................... 8 1.4.2 Other sub-contractor ............................................................................... 7 1.4.3 Electrical installation contractor ............................................................. 7
2. References.................................................................................................. 9 3. General requirements............................................................................. 10 3.1 3.2
Doc. kind Title
Standardisation ................................................................................................ 10 3.1.1 Electrical standards to apply: ................................................................ 10 General technical requirements ...................................................................... 11 3.2.1 Maximum allowed resistances within earthing system ........................ 11 3.2.2 Earthing conductors material and coating/colour coding ..................... 11 3.2.3 Earthing conductor termination ............................................................ 11 3.2.4 Earthing conductor minimum dimensions ............................................ 11
Technical Requirements Earthing
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4. Particular requirements ......................................................................... 13 4.1 4.2
4.3
4.4
The earthing systems -Equipotential bonding, PE, IE(SC) and IS ............. 13 4.1.1 Earth bars .............................................................................................. 14 Equipotential bonding system ......................................................................... 15 4.2.1 Earthing principles for equipotential bonding system .......................... 15 4.2.2 Examples of when complementary equipotential bonding is required ................................................................................................. 16 4.2.3 Examples of when complementary equipotential bonding is not normally required ............................................................................ 17 4.2.4 Installation............................................................................................. 17 4.2.5 Earth bosses .......................................................................................... 19 4.2.6 Base frames (BF) –earth bosses ............................................................ 21 4.2.7 Wall sections of GT and LCM enclosures ............................................ 21 4.2.8 Other connection point for earthing ...................................................... 21 4.2.9 Connection of metallic part, structure or component............................ 22 Protective Earth, PE system ............................................................................ 23 4.3.1 Earthing principles PE system .............................................................. 23 4.3.2 Disconnecting times at ground fault ..................................................... 23 4.3.3 Cabinets -Separate PE earthing bars ..................................................... 24 4.3.4 Junction boxes -PE terminals ................................................................ 24 4.3.5 PE conductor in power cables ............................................................... 24 Instrument Earth (IE), (SC) system ............................................................... 25 4.4.1 Earthing principles IE system ............................................................... 25 4.4.2 Cabinets -Separate IE earthing bars ...................................................... 25 4.4.3 Junction boxes -terminals ..................................................................... 25
5. Divergences and additions ..................................................................... 26 5.1 5.2 5.3
Doc. kind Title
Hazardous Area ................................................................................................ 26 5.1.1 Intrinsically Safe Earth (IS) .................................................................. 26 Offshore............................................................................................................. 28 5.2.1 Armoured/braided cables ...................................................................... 28 External grid in ground ................................................................................... 29 5.3.1 Dimension and material, unless otherwise specified: ........................... 29 5.3.2 Ground rods .......................................................................................... 29 5.3.3 Periodic measurement of impedance .................................................... 29 5.3.4 Maximum resistance to ground ............................................................. 29 5.3.5 Coupling of grid in ground at GT to grid in ground at site ................... 29
Technical Requirements Earthing
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1. General 1.1 Introduction Intended users of this document are suppliers, designers of electrical equipment and systems, mounting staff at site and at Siemens assembly work shop, inspection and application personnel. The purpose of this document is to provide the minimum requirements concerning the earthing, sometimes called earthing, system for the Electrical Installation. This document is one out of a subset of documents specifying different aspects of the electrical installation (see “References”). A user of this or any other document in the subset shall also read “General Requirements” (see “References”). A supplier shall conform to the requirements stated in this document, and if necessary in writing detail express the points of divergence to Siemens.
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1.2 Definitions and explanations LV
U < 1000 VAC, (1000V) but same as EN/IEC 60204-1 regarding earthing, among others a description of measuring method for ground resistance can be found. This standard can be used for both safe and hazardous area. IEC 62305 Lightning protection HD 637/IEC 61936-1 Mainly to be used by civil contractor in order to determine the maximum resistance to earth (see “Maximum allowed resistances within earthing system”). NFPA 70 for North American Markets applications National Electric Code-Article 250 specifically deals with bonding and earthing requirements for American installations.
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3.2 General technical requirements 3.2.1 Maximum allowed resistances within earthing system Within earthing system there shall not occur resistances exceeding 1Ω. •
From connection point (earth bar) at LCM/CCR to transformer(high voltage transformer) ≤ 1Ω For example, and of special importance, is the resistance from IS bar in control cabinet and to the earthing point at transformer.
•
From any metallic part within protective bonding system to another metallic part, earth boss or to grid in ground ≤ 1 Ω
3.2.2 Earth conductors material and coating/colour coding Purpose
Material
Coating/Colour coding
Protective bonding
Cu
Yellow/green (pot eq, of safety reasons)
Protective Earth, (PE)
Cu
Yellow/green
Inst. Earth, Screens (IE/SC)
Cu
Transparent
Main conductor to IE/SC bars
Cu
Grey
Intrinsically Safe (IS)
Cu
Black
Down conductors
Cu
Yellow/green
In ground
Cu
Uncoated
3.2.3 Earth conductor termination Unless terminated in terminals, the ends of all earth conductor wires shall be fitted with crimped on cable lugs. 3.2.4 Earth conductor minimum dimensions The determination of dimensions is based on several factors including mechanical strength and endurance. The LV system requires calculations based on actual case with present conditions to safely conduct highest possible ground fault current to earth.
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3.2.4.1 Protective bonding, unless otherwise specified (see also fig 6): Use
Metric Wire Size
Main components in line of string
AWG equivalent
When to use
70 mm2 CU
2/0
Always
70 mm2 CU
(Gear box, GT, start motor) Down conductors (see fig. 1)
2/0
Always
2
6
Always
2
6
If req. (>1Ω)*
2
6
Always
2
6
If req. (>1Ω)*
2
16 mm CU
Motors Cable trays/ladders Junction boxes GT Enclosure wall and roof sections
16 mm CU 16 mm CU 16 mm CU
GT and LCM Building structures
16 mm CU
6
If req. (>1Ω)*
Mechanical constructions
16 mm2 CU
6
If req. (>1Ω)*
Pipes (e.g. gas fuel pipe)
16 mm2 CU
6
If req. (>1Ω)*
Conduits for cables
6 mm2 CU
10
If req. (>1Ω)*
10
If req. (>1Ω)*
Instruments
2
6 mm CU
3.2.4.2 PE ground conductors, unless otherwise specified: Power supply cabinets, in general Earth bar common for more than one cabinet Cabinet when separate for start motor or fuel
70 mm2 CU
2/0
Always
2
2x3/0
Always
2
2x2/0
Always
2x95 mm CU 2x70 mm CU 2
Cabinet when separate for transformer
95 mm CU
3/0
Always
Control Cabinets
16 mm2 CU
6
Always
Doors and lids of cabinets and boxes
6 mm2 CU
10
If req. (>1Ω)*
10
If req. (>1Ω)*
10
Always
3.2.4.3 Instrument Earth, unless otherwise specified: Instruments IS, SC bars to PE
6 mm2 CU 2
6 mm CU
* Each system supplier must in their self-control check the 1Ω-requirement and should present a signed test protocol or a signed declaration of conformity with these requirements. Manufacturers own instructions must always be followed.
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4. Particular requirements 4.1 The earthing systems -Protective bonding, PE, IE (SC) and IS The separation of the different types of earthing is illustrated in fig 2. Safety reasons:
Protective Bonding, PE earth
Functional earthing:
IE (SC) and IS
The IE (SC) and IS earth bars in a cabinet (cubicle) are shown in fig 2. Each of those earth bars shall be isolated and have its own connection to earth as close as possible to grid in ground. Separation of the different earthing systems especially the IS system shall be followed through as far as possible, also inside the cabinet.
Fig 2: The principle of separating the different types of earthing systems The importance of low impedance to PE and that no potential differences appear overrides the risk of circulating currents when earthing the junction boxes by both PE (not IS circuits, see ch 5) and protective bonding system.
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4.1.1 Earth bars Different types of earth bars shall be mounted on stands against walls, in cabinets or between earth bosses on base frames and be prepared with holes for bolting of earthing wires. 4.1.1.1 Material and marking of earth bars
Doc. kind Title
Purpose
Material
Marking
Protective bonding
Cu /(stainless steel when mounted on earth bosses of stainless steel)
unmarked
Protective Earth (PE)
Cu
PE, yellow/green
Instrument Earth (IE)
Cu
SC, Uncoated
Intrinsically Safe (IS)
-
See “Divergences and additions”
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4.2 Protective bonding system 4.2.1 Earthing principles for protective bonding system All reachable metallic parts or metallic parts placed where sparks imply danger shall have the same electric potential. The metallic parts shall be in good metallic contact ( ≤ 1 Ω) with each other and be connected to the protective bonding system which is connected to earth (grid in ground). Construction or equipment parts that are welded or bolted together in a way that ensures endurable good metallic contact can be considered as one unit that needs earthing Where good metallic contact (>1 Ω) between parts is not ensured, especially for electric components, complementary protective bonding using Cu conductors shall be done. The Cu conductors shall link together parts (serial bonding as in fig 4), connect the part closer to earth (earth boss at BF as in fig 3) or directly to earth (to grid in ground). Metallic part
Metallic part
●
Metallic part
BF
Fig 3. Preferred method of Protective bonding (“star connection”)
Metallic part
Metallic part
Metallic part
BF
Fig 4. Acceptable method (serial bonding or daisy chaining) if no metallic parting the chain is likely to be removed
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4.2.2 Examples of when complementary protective bonding is required •
Electrical equipment such as junction boxes and motors
Examples of assemblies where the bolting does not ensure good metallic contact and accordingly shall have complementary protective bonding: •
Assemblies or change over from one part to another with non conducting material (paint, bellows, gaskets) in between the assembled parts
•
Assemblies where the material is likely to corrode (e.g. carbon steel, dissimilar metals) such as pipe connection flanges, bolts etc of carbon steel.
Fig 5: Complementary bonding is required where there is paint or other non conducting material in between the metallic parts and the bolting does not ensure good contact. “Non conducting material” can also be the case where corrosion is likely to develop a less conducting layer in between the metallic parts. Threaded bolt connection should utilize lock washers to maintain mechanical integrity of the connection.
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4.2.3 Examples of when complementary protective bonding is not normally required Some assemblies where complementary protective bonding is not normally required are: •
Assemblies or change over from one part to another where endurable good metallic contact is ensured
•
Piping change over where pipe, flange, bolts, nuts and washers are of stainless steel
The three different situations illustrated in Fig 6 are all in the normal case bonds that do not need complementary Protective bonding. However, type and thickness of paint varies which can make the use of toothed plate connectors uncertain. Hence the resistance must be verified to not exceed maximum allowed level (see chapter 3.2.1 “Maximum allowed resistances within earthing system” and note * in chapter 3.2.4).
Fig 6. One example of good metallic contact is non corrosive metals bolted together. In the case where the surfaces are painted it can be sufficient to use serrated/toothed lock washers or self tapping screws, the resistance from one part to the other shall be verified not to exceed maximum allowed resistance.. Lock washers shall be used to ensure mechanical integrity of earthing connection.. 4.2.4 Installation The protective connection shall be carried out by earth conductors between separate connection points for that purpose only (see coming chapters)Where redundancy is required, diagonal and parallel connection (see fig 1 and 6) shall be used. Crossing of the conductors minimizes the encircled area in which a magnetic field, if it varies, gives rise to circulating earth currents.
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Fig 6: The principle of Siemens’s case of typical installation of protective bonding
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4.2.5 Earth bosses All earth bosses shall have a threaded hole of the dimension M10 see “References” for design drawing of an earth boss 4.2.5.1 Connection point A connection point for a metallic part in Protective bonding system shall on base frames consist of a puck or “earth boss” with ensured metallic contact with base frame. 4.2.5.2 Connection to grid in ground The connection to grid in ground shall be carried out by down conductor from earth boss on BF (see fig 1 and 6). 4.2.5.3 Prefabricated Earth bosses shall as far as possible be prefabricated and welded into base frame or structure. 4.2.5.4 Material and marking
Doc. kind Title
Purpose
Material
Marking
Protective bonding
Stainless steel
unmarked
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4.2.5.5 Installation It is strongly recommended to connect the earth conductors individually. Therefore, it is recommended to use an earth bar as soon as there is more than one connection at the same point (see fig 8). On the BF the bar shall be mounted between earth bosses and be prepared with one connection bolt for each earth conductor. There shall not be more than 5 earth conductors at one earth boss (see fig 7). If there is a need for more than 5 connections in the same point an earth bar shall be used. Threaded rod Locking nut Locking washer Cable shoes /lugs
Cable shoes /lugs ≤60 mm
Earth Boss
Fig 7: Earth boss with threaded rod, the maximum 5 cable lugs, locking washer and nut (see “References” for design document).
M10
Earth Boss M10
Earth Bar
Fig 8: Earth bar bolted between two earth bosses in order to achieve individual connection of all earth conductors on BF (see “References” for design document). The threaded rod shall be screwed down to bottom of earth boss and be cut so that it is not sticking out more than 10 mm from nut. The edge of the rod shall be smoothened. Alternatively, the rod might be sticking out just enough to fit an end protection/cap.
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4.2.6 Base frames (BF) –earth bosses The main base frame for GT, LCM and other large individual base frames shall be prepared with at least two diagonally placed earth bosses. Examples of large individual base frames (see fig 6) are the ones for external lube oil cooler, gas unit, compressor or generator and double or liquid fuel unit. Metallic part
Connecting point
Base frames for GT, LCM, Generator
≥ 2 pcs Earth bosses (M10)
During the painting process of the baseframe, earthing surfaces shall be protected from paint at a minimum on the washer and bolt. When carrying out the electrical installation it shall be ensured that all washers and bolts on earth bosses are of stainless steel material. 4.2.7 Wall sections of GT and LCM enclosures The wall sections, which mean the different frame structures that are bolted together forming the walls of the enclosures, shall be linked together. Then, and of special importance, links to the foundation frame must be done since the wall sections are standing on non conducting material. The sheet metal panels screwed on the wall section are considered to be in good enough metallic contact with the frame structures. 4.2.8 Other connection point for earthing Other metallic parts or components than specified in this document shall at least be prepared with two (preferably diagonally located) earth bolts or threaded holes. That is, even if it is a part that does not actually need redundancy. 4.2.8.1 Installation If necessary, earth connection points can be made by drilling and threading in a base frame to create a connection point. The connection shall be cleared from grit and dirt including paint to ensure a proper electrical connection. All connections shall afterwards be well corrosion protected.
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4.2.9 Connection of metallic part, structure or component Examples of metallic parts, structures and components that shall be connected to protective bonding system or direct to grid in ground: See also “References” for document with references to specific aspects of electrical installation. Metallic part
Connecting point
Remark
Junction box
Earth bolt on outside
See fig 2
Cabinet
Earth bar
See fig 2
Doors and lids
Cu conductor Links1
Base Frames
Earth Boss
See “ Base frames (BF) –earth bosses
Buildings, sections
Cu conductor Links1
Each wall section, (see also fig 6)
Change over from part to part with non conducting material in between
Cu conductor Links1
e.g. paint, bellows or gaskets in between parts
Structure and rail
Bar/boss/bolt/threaded hole
At least every 25:th meter
Pipe/tube general
Special pipe clamp
Incoming pipes shall be connected at entry of GT
Gas/liquid fuel pipe
Bolt/hole/pipe clamp
Connected at entry of GT and at fuel manifolder2
Machine
Bolt/threaded hole
e.g. LV induction motors
Component
Bolt/threaded hole
e.g. Main terminal box, generator
Ladder, tray, conduit
Crimp lugs
If required (>1 Ohm) At beginning and end of each run (if ensured contact at joints)
1
Change over from part to part with non conducting material in between and each section of a building such as wall and roof sections of GT enclosure, LCM or air module must be linked together and connected to equipotential bonding system. The connecting links shall be of Cu conductors (yellow and green) which may be connected to frame work by self-tapping screws. 2
The earthing of fuel pipes shall be as follows:
• On Siemens side of, and immediately next to, the delivery limit of the fuel pipe towards the customer/fuel supplier, there must be a connection point for earthing. To this point a earthing wire shall be connected to join this point to earth. • Each fuel manifold shall be equipped with a connection point for earthing wire. To this point shall be connected a earthing wire connecting the manifold to earth.
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4.3 Protective Earth, PE system 4.3.1 Earthing principles PE system •
All metallic enclosures for electrical equipment with system voltage ≥ 50VAC or ≥ 120 VDC shall be grounded to PE system.
•
The earthing arrangement should ensure a ground fault current return path so that the earth fault protection will sense the fault.
•
The earth conductors and connections should withstand the ground fault current for the duration of the fault.
•
The earthing conductors shall be continuous. Structural changes after installation should not interrupt the earth conductor. Equipment enclosures should not be used as part of the earth conductor.
•
The earth conductors shall be mechanically protected.
4.3.2 Disconnecting times at ground fault At ground fault, for example in the case of a fault between live part and metallic enclosure, the over current protection shall disconnect the supply within following times: Case
Maximum disconnecting time
In general for machines such as the GT:
5s
Circuits with socket-outlets, handheld or portable equipment: At 230 VAC system
0,4s
At 400 VAC system
0,2s
For installations in North American Markets, ground fault protection devices shall adhere to the requirements of NFPA 70 and shall be listed for use by a NRTL.
Doc. kind Title
Technical Requirements Earthing
Project
Electrical Installation Gas Turbines
Document number
Siemens Industrial Turbomachinery
1CS77950
Lang.
en
Rev. ind. Sheet
R
No. of sh.
23 31
4.3.3 Cabinets -Separate PE earth bars Cabinets shall be equipped with separate internal earth bars for PE earthing only. The PE bar shall be connected to an earth boss (e.g. in LCM base frame) for PE earthing only (see fig 2). Each cable's protective lead shall be separately attached to the PE bar (e.g. via PE terminals). The earth bar must be of sufficient size to connect also the external cable earthings. To ensure minimized impedance doors (even if it is “connected” by hinges), mounting plate, and PE terminals, shall be connected with a PE wire to the PE earth bar (exceptions see 3.2.4.2). 4.3.4 Junction boxes -PE terminals Metallic junction boxes with system voltage that requires PE earthing (see “Earthing principles PE system” above) shall be equipped with separate earth terminals for PE earthing only. The PE terminals are in metallic contact with the enclosure. The PE terminals shall have yellow/green marking. Each power cable's protective lead (PE conductor) should be separately attached to the PE terminals (not for IS circuits, see ch 5). To ensure minimized impedance doors or lids (even if it is “connected” by hinges or bolts) and mounting plate, shall be connected with a PE wire to the enclosure (exceptions see 3.2.4.2). See also “References” for document about cabinets and boxes. 4.3.5 PE conductor in power cables The concentric wire in a symmetric power cable is used as PE conductor (for armour or braid see “Offshore”). Accordingly, it shall be covered with sleeves colored yellow/green and be connected to the PE bar or terminal.
Doc. kind Title
Technical Requirements Earthing
Project
Electrical Installation Gas Turbines
Document number
Siemens Industrial Turbomachinery
1CS77950
Lang.
en
Rev. ind. Sheet
R
No. of sh.
24 31
4.4 Instrument Earth (IE), (SC) system 4.4.1 Earthing principles IE system •
The control or signal cables screens (for armour or braid see “Offshore”) shall only be connected to IE ground (SC) in the feeding end of the cable. In the outer (field) end the screens shall be isolated, terminated at empty terminals or if the cable have both outer and inner screens the outer screen shall normally be connected to the PE system in both ends (see fig 2 and circuit diagram).
•
The cable screens shall be as short as possible at connecting points (due to that the screens serves as “antennas”)
•
The cable screens shall be covered with a plastic transparent sleeve.
4.4.2 Cabinets -Separate IE earth bars Cabinets shall be equipped with separate internal earth bars for IE (SC) earthing only (see fig 2). The IE bar shall be insulated from enclosure and other earthing systems in cabinet. The IE bar shall be separately connected as close to earth as possible. 4.4.3 Junction boxes -terminals In junction boxes the signal cabling screens only “pass through” via terminals. If the external signal cabling screens don’t match the internal such as when the external cable is of a collectively screened multi core cable type. Then, linking of terminals to connect the screens together shall be done. See also “References” for document about cabinets and boxes.
Doc. kind Title
Technical Requirements Earthing
Project
Electrical Installation Gas Turbines
Document number
Siemens Industrial Turbomachinery
1CS77950
Lang.
en
Rev. ind. Sheet
R
No. of sh.
25 31
5. Divergences and additions 5.1 Hazardous Area No deviations or additions except from below 5.1.1 Intrinsically Safe Earth (IS) The IS earth is a separate earthing system for the cable screens in the intrinsically safe circuits. 5.1.1.1 Earthing principles IS system •
The cable screens in the IS system shall only be connected to IS ground in the feeding end of the cable. In the outer end the screens shall be insulated or terminated at empty terminals (see circuit diagram).
•
The cable screens shall be as short as possible at connecting points (due to that the screens serves as “antennas” for disturbances)
•
The cable screens shall be covered with a plastic black sleeve.
•
The IS system shall be connected to the protective bonding system in one point only.
•
No PE conductor from AC power distribution is allowed to be connected to remote I/O in the Junction box for IS circuits The remote I/O must only be connected to the protective bonding system..
5.1.1.2 Connection to earth Illustrated in figure 2 is that the IS connection point is separated from any other earth connecting point until the boxes or cabinets incoming earth boss or earth bar. That is important, not only to achieve individual connection of the earth conductor, but also in order to effectively reduce high frequency disturbances. 5.1.1.3 Earth conductors material and coating
Doc. kind Title
Purpose
Material
Marking/Coating
Intrinsically Safe (IS)
Cu
Black
Technical Requirements Earthing
Project
Electrical Installation Gas Turbines
Document number
Siemens Industrial Turbomachinery
1CS77950
Lang.
en
Rev. ind. Sheet
R
No. of sh.
26 31
5.1.1.4 Earth bar Purpose
Material
Marking/Coating
Intrinsically Safe (IS)
Cu
IS
5.1.1.5 Cabinets and Junction boxes for distributed I/O – Separate IS earth bars Cabinets shall be equipped with separate internal earth bars for IS earthing only (see fig 2). The IS bar shall be insulated from enclosure and other earthing systems. The IS bar shall be separately connected as close to earth as possible. 5.1.1.6 Junction boxes for distributed I/O – Separate IS earth bars Junction boxes for distributed I/O shall be equipped with separate internal earth bars for IS earthing only (see fig 2). The IS bar shall be insulated from enclosure and other earthing systems. The IS bar shall be separately connected as close to earth as possible. In junction boxes for distributed I/O for IS circuits it shall not be connected any PE conductor from AC low voltage power supply distribution. The enclosure and PE bar in an I/O junction box for IS circuits shall be connected to Protective bonding system in field end only. 5.1.1.7 Junction boxes –terminals In the IS unique, junction boxes the IS cabling screens only “pass trough” via terminals. In the case of junction boxes for distributed I/O see “Cabinets and Junction boxes for distributed I/O” above. See also “References” for document about cabinets and boxes.
Doc. kind Title
Technical Requirements Earthing
Project
Electrical Installation Gas Turbines
Document number
Siemens Industrial Turbomachinery
1CS77950
Lang.
en
Rev. ind. Sheet
R
No. of sh.
27 31
5.2 Offshore See “References” for document about in general valid requirements which covers also the offshore application. 5.2.1 Armoured/braided cables Offshore cables have reinforced screening (armour) in form of a braid or tightly placed steel wires under the outer coating. This type of armour is stiff to handle, especially the steel wire armoured type. The armour/braid shall in all cables be connected to PE system in both ends. 5.2.1.1 Termination of the armour/braid Junction boxes Power cables (U≥50 VAC, 75 VDC)
-armour/braid to PE system
Junction boxes with their glands must be prepared to connect the armour/braid to PE earth system (enclosure). Signal cables (U< 50 VAC, 75 VDC)
-armour/braid/outer screen to PE system
Junction boxes with their glands must be prepared to connect the armour/braid/outer screen to PE earth system (enclosure). The inner screen/screens shall as always pass trough via terminals and be connected to IE (SC) bar in feeding end only. 5.2.1.2 Termination of the armour/braid -Cabinets Cabinets must be prepared to connect the armour/braid to PE system (enclosure). One method is to use multi cable transit sealing that connects the screens to cabinet enclosure. Other methods are to use glands or to use non conducting sealing and connect the screens by clamps on bars mounted in contact with enclosure.
Doc. kind Title
Technical Requirements Earthing
Project
Electrical Installation Gas Turbines
Document number
Siemens Industrial Turbomachinery
1CS77950
Lang.
en
Rev. ind. Sheet
R
No. of sh.
28 31
5.3 External grid in ground A complete GT installation demands an external grid in ground with electric potential in common with the grid in ground for the whole plant. The grid in ground is not part of Siemens standard delivery (see “Suppliers responsibility”). How to design the earthing system at site depends of local circumstances and conditions but the requirements in this chapter forms, as everything else in this document, Siemens minimum requirements. The principle of a typical grid in ground at GT is illustrated in figure 6 under “Protective bonding system”. Grid in ground should be buried as shown in figure 10. 5.3.1 Dimension and material, unless otherwise specified: •
In ground
95 mm2 / 3/0AWG CU
•
Down conductors in general
70 mm2 / 2/0 AWG CU
•
Down conductors from GT base frame
95 mm2 /3/0 AWG CU
5.3.2 Ground rods Ground rods (or, depending on ground conditions, other device such as Cu sheet metal) are necessary if ground system does not already exist on site. They are to be buried vertically in the ground with a depth adapted to present ground conditions (minimum 3m). Design and connection of a rod is shown in figure 9 (see also fig 6). Connections shall be done by pressing and not by welding. 5.3.3 Periodic measurement of impedance Measurements to check the earthing system impedance shall be executed periodically according to standardized method and local conditions. 5.3.4 Maximum resistance to ground The grid in ground shall reach a maximum resistance to ground of ≤ 1 Ω . That is, the resistance within the fenced area for distribution plant. See “Electrical standards to apply” for valid directive and for standard of measuring method. 5.3.5 Coupling of grid in ground at GT to grid in ground at site The grid in ground at GT shall be connected to the grid in ground for LV power supply and control equipment (LCM/CCR). The grid at GT and the other grid or grids shall be connected to each other (see also figure 2 and 6).
Doc. kind Title
Technical Requirements Earthing
Project
Electrical Installation Gas Turbines
Document number
Siemens Industrial Turbomachinery
1CS77950
Lang.
en
Rev. ind. Sheet
R
No. of sh.
29 31
Fig 9: Design of earthing rod
Doc. kind Title
Technical Requirements Earthing
Project
Electrical Installation Gas Turbines
Document number
Siemens Industrial Turbomachinery
1CS77950
Lang.
en
Rev. ind. Sheet
R
No. of sh.
30 31
Calculated depth depending on local conditions
Fig 10: Example of Cu wires placement in ground
Doc. kind Title
Technical Requirements Earthing
Project
Electrical Installation Gas Turbines
Document number
Siemens Industrial Turbomachinery
1CS77950
Lang.
en
Rev. ind. Sheet
R
No. of sh.
31 31