Type MPB/MPGTest Plug and Universal Test Block

Type MPB/MPGTest Plug and Universal Test Block

Test block with test pluginserted ready for testing relaysin non-draw-out cases

Features

l On-load testing of relays andmeters without disturbing panelwiring.

l Reduced cost of commissioningand routine maintenance.

l Simplified and safer testing.

Application

Type MPB test plug is used for testingrelays and meters in drawout cases.In conjunction with type MPG testblock, it can be used for testingrelays and meters in non-drawoutcases of any make.

Description

MPB test plug

Type MPB test plug has ten pairs ofsilver plated finger contacts whichare linked to the test sockets. Thetop and bottom contact strips ofeach finger are separated byinsulation.

To avoid the possible paralleling ofdc trip circuits, the top contact stripon contact fingers 3 and 4 isshortened to isolate the externalcircuit before the test circuit isconnected to the relay.

The plug body is a two partmoulding. One part is coloured redto indicate live external connectionsand the other is coloured black toindicate the isolated circuits of therelay or meter. Projections on theback of the body prevent the plugfrom being inserted incorrectly.

Drawout cases have readilyaccessible contacts and it is onlynecessary to remove the cover of therelay or meter and insert the testplug. All test connections are madeautomatically when the plug isinserted and normal conditions arerestored when the plug iswithdrawn. It is not necessary to takecircuits out of service or disturb anypanel wiring. Current transformerscan be automatically shorted whenthe plug is inserted along with theshorting links.

MPG test block

Type MPG test block is a two partmoulding in which ten pairs of silverplated contacts are housed. Eachpair of contact is spring loaded andseparated from its neighbour by aninsulated barrier. Permanentconnections are made between thetest block and the relay or meterand the test plug is inserted into theblock for testing.

Test blocks can be supplied suitablefor flush mounting. A protectivecover which is easily removable, isfitted to the block when not in use.

The contacts of the test block closeautomatically when the test plug isremoved from it except the tripcontact which remains open until thecover is replaced. A contact fingerattached to the cover completes thecircuit. In this way, it is possible toisolate the trip circuit by justremoving the test block cover andthus preventing unnecessary trippingduring testing.

Insulation

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

Connections

Test plug supplied for use with relaysis provided with sockets and sixwander plugs for makingconnections to the external circuits.Three links fitted with wander plugsare also supplied.

Dimensions and weights

Maximum overall dimensions ApproximateType Height Width Depth gross weight

mm mm mm Kg.

MPB test plug 50 159 100 0.8(without shorting linksand wander plugs)

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 mountingdetails 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 tropicalenvironments.

Special test plugs and blocks are supplied for use with distance schemesand details are available on request.

PR:043:0799:A Printed in India.

ALSTOM Limited Pallavaram Works: 19/1, GST Road, Pallavaram, Chennai-600 043. India.Tel: 91-044-2368621 Fax: 91-044-2367276 Email: plw.applications@alstom.sprintrpg.eml.vsnl.net.in.

' 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 shouldonly 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