GEC Alsthom 10 contact test blocks 5

[LincolnKeith]

There is a thread from 09 with the title of "GEC Alsthom 10 contact test blocks" asking about the MPB mouth organ test plug. Just in case anybody googles for information about this plug, and comes across this, the following may help.

I have just received 2 plugs from India, a company called Nelster Welcon. The plugs are Series NW-RTPL, web page

http://www.testterminalblock.com/relay-test-blocks.html

The cost of 2 plugs plus shipping to UK was USD 340, and they took 5 days to arrive.

They are a copy of the original plug (including being the same colour). The quality is not quite as good as the original, I don't expect them to last 40 years as my existing plug has done - but they will probably see me out.

I hope this is of use to somebody.

Best regards.

 

[ScottyUK]

Thanks Keith, didn't think anyone still made them.

 

[LincolnKeith]

Hi Scotty,

It was just the result of a random google search. I was not expecting anything (except maybe ebay) but I wanted a second plug for the rare occasions where the relay has terminals at the top also.
I imagine that, in India, they have a lot of old GEC relays which still work well. When these relays were made, they where very robust and in very good cases. I see plenty of GEC and English Electric relays and, on one site, even Chamberlain & Hookham. Mostly these relays give acceptable results when tested.
There is something satisfying about seeing a disc turn when you are injecting current, much better than the boring modern relays.

 

[RRaghunath]

I heard in west, Test Terminal Blocks are on their way out from the relay panels!
If true, is it because periodic secondary injection test is no more a requirement with numerical relays!

Rompicherla Raghunath

 

[thermionic1]

"I heard in west, Test Terminal Blocks are on their way out from the relay panels!
If true, is it because periodic secondary injection test is no more a requirement with numerical relays!"

This may be the case sometimes with packaged, large combined cycle generator protection, but in North America, we have NERC to comply with. This means that every so often routine, or maintenance tests shall be performed and documented on protection devices. Even for simple meter and I/O checks, this means lifting wires, if there is no other way to safely test the devices. Many owners of these plants are learning the hard way that some kind of isolation / test device is needed.

In the utility world, especially in the USA, ABB Type FT test switches are very common. There may be better designs out there, but these units work quite well, once understood.

 

[dpc]

I heard in west, Test Terminal Blocks are on their way out from the relay panels!

Actually, I think they've become more important since our leading relay manufacturer, Schweitzer, does not make draw-out cases for their relays. Dr. Schweitzer has argued in the past that test switches are not necessary, but not sure he's convinced too many people. As mentioned the old standard ABB (Westinghouse) FT switches, and copies, are still quite prevalent in the US at least.

 

[RRaghunath]

Thanks thermionic1 and DPC for sharing your views.
It is also a fact, the numerical relay manufacturers state that periodic secondary injection testing of these relays is not a requirement considering that there is no possibility of drift in settings (all static) and that the watchdog would warn the operator in case of any problem in the hardware or software of the relay.

Rompicherla Raghunath

 

[dpc]

I think secondary injection is still necessary for commissioning but agree it is probably not required on a routine basis unless there is some reason for concern.