Any 'Power' electricians on list?

[Andrew Mawson]

Any 'Power' electricians on list?

Anyone on list familiar with Merlin Gerin "Compact C 250 N" three phase 250 amp circuit breakers when used with a Merlin Gerin "Vigilohm RCR C250" differential relay? Googling gives me data on the later 'NS' versions but these date from the late 1990's and seem somewhat different.

I'm trying to 'reverse engineer' and draw up a circuit for a large generator (100KVA) where the circuit breaker is the main isolator and has two auxillary functions, a contact 'closed for isolated' and an input pair that I suspect are a trip driven by the other device which are marked "C1 - C2" and "MX" through which I measure no continuity. I understand the contact as it is used in an interlock elsewhere, but not what the trip expects (if it is a trip). The 'differential relay' is actually a current transformer through which the 3 phases, and neutral pass, and has two outputs, presumably coils, which go to a conventional relay that must have had its wiring mucked about as there is no connection to one side of it's coil ! However this goes on to the trip circuit.

If I can find what the trip expects and what the differential relay (current transformer) gives out I can sort the relay easily so anyone with any older documents please shout.

AWEM

[dave]

This sounds real fun. Esp. testing the thing! Is this a 440V beasty btw - ah yess I see it is. Good luck.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Andrew Mawson" saying something like:

I suspect you have a changeover contacter there. On mains restoration, the current tranformer detects voltage and trips the contacter back to the mains state.

Whatever; without seeing it and the relevant panelwork and circuitry, I'm just guessing. It certainly sounds like the stuff I used to put together. What age is the genset and control panel?

[Andrew Mawson]

"Vigilohm

continuity. I

relay'

anyone

restoration,

circuitry,

Dave,

No it's an isolator but not a change over. It's fiited with a trip coil which I've proved to be open circuit. Trouble is it's dated 1987 so bits aren't easily come by, and the Merlin Gerin "Vigilohm RCR C250" differential relay which has a power input and a detetor coil output both of which are open circuit and probably blown by the same fault years ago:{

AWEM

[Stuart]

I've contacted Merlin before and had a prompt and helpful reply. If you can't find an answer on theor website try emailing them.