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Type MPB/MPG Test Plug and Universal Test Block

Type MPB/MPG Test Plug and Universal Test Block

Test block with test plug inserted ready for testing relays in non-draw-out cases

Features l

On-load testing of relays and meters without disturbing panel wiring.

l

Reduced cost of commissioning and routine maintenance.

l

Simplified and safer testing.

Application Type MPB test plug is used for testing relays and meters in drawout cases. In conjunction with type MPG test block, it can be used for testing relays and meters in non-drawout cases of any make.

Description MPB test plug Type MPB test plug has ten pairs of silver plated finger contacts which are linked to the test sockets. The top and bottom contact strips of each finger are separated by insulation.

To avoid the possible paralleling of dc trip circuits, the top contact strip on contact fingers 3 and 4 is shortened to isolate the external circuit before the test circuit is connected to the relay. The plug body is a two part moulding. One part is coloured red to indicate `live’ external connections and the other is coloured black to indicate the isolated circuits of the relay or meter. Projections on the back of the body prevent the plug from being inserted incorrectly. Drawout cases have readily accessible contacts and it is only necessary to remove the cover of the relay or meter and insert the test plug. All test connections are made automatically when the plug is inserted and normal conditions are restored when the plug is withdrawn. It is not necessary to take circuits out of service or disturb any panel wiring. Current transformers can be automatically shorted when the plug is inserted along with the shorting links.

MPG test block Type MPG test block is a two part moulding in which ten pairs of silver plated contacts are housed. Each pair of contact is spring loaded and separated from its neighbour by an insulated barrier. Permanent connections are made between the test block and the relay or meter and the test plug is inserted into the block for testing. Test blocks can be supplied suitable for flush mounting. A protective cover which is easily removable, is fitted to the block when not in use. The contacts of the test block close automatically when the test plug is removed from it except the trip contact which remains open until the cover is replaced. A contact finger attached to the cover completes the circuit. In this way, it is possible to isolate the trip circuit by just removing the test block cover and thus preventing unnecessary tripping during testing.

Insulation The test plug and the test block will meet the requirements of IS 3231/ IEC 255-5 series C-2 KV for 1 minute.

Connections Test plug supplied for use with relays is provided with sockets and six wander plugs for making connections to the external circuits. Three links fitted with wander plugs are also supplied.

Dimensions and weights Type

Maximum overall dimensions Height Width Depth mm mm mm

Approximate gross weight Kg.

MPB test plug (without shorting links and wander plugs)

50

159

100

0.8

MPG test block

95

181

72*

1.3

* Add 76 mm for maximum length of terminal studs, alternatively, 29 mm for terminal screws. Certified dimensional drawing of outlines, panel cut-outs and mounting details are available on request. The approximate gross weights given above are inclusive of cartons, mounting appendages and terminal details. The test plug and the test block are suitable for use in tropical environments. Special test plugs and blocks are supplied for use with distance schemes and details are available on request.

ALSTOM Limited Pallavaram Works: 19/1, GST Road, Pallavaram, Chennai-600 043. India. Tel: 91-044-2368621 Fax: 91-044-2367276 Email: [email protected]. © 1998 ALSTOM Limited Our policy is one of continuous development. Accordingly the design of our products may change at any time. Whilst every effort is made to produce up to date literature, this brochure should only be regarded as a guide and is intended for information purposes only. Its contents do not constitute an offer for sale or advice on the application of any product referred to in it. ALSTOM Limited cannot be held responsible for any reliance on any decision taken on its contents without specific advice

PR:043:0799:A

Printed in India.