RCD type

eckersecker · Oct 23, 2011

Came across the above RCD whilst working on a TT system. It had no indication of tripping currents on it. There was no main fuse so I need to record it's details including BS number. I tested it with a 30mA ramp test and it did not trip. So I fitted a 30 mA RCD to the shed supply I put in assuming I had discrimination. Any details would be much appreciated.

Sparky Ninja · Oct 23, 2011

Are you sure it's an RCD?

Guest123 · Oct 23, 2011

Looks like a VOELCB with the little yellow test button on it. Needs taking out as it probably doesn't work anymore.

Might even be an early ELCB.

BS 842 if memory serves.

eckersecker · Oct 23, 2011

Yes reasonably! , if you push the button under the switch it trips, and a zs reading from the sockets in the house trips it, a no trip test does not. I took the lid off and there is a big copper coil inside.

SirKit Breaker · Oct 23, 2011

I'm with Widdler, but i am curious to know what the yellow ish button is between the 2 mounting screws, is it a mechanical trip button? If so it could be a RCD of some sort.

Cheers........Howard

eckersecker · Oct 23, 2011

Does trip , as stated above and by home owner. Not possible for me to take out as there is no fuse before it. It isolates the house before the meter. I think this is weird as if the owner is unscrupulous he could switch off and wire in stuff before the meter.

Sparky Ninja · Oct 23, 2011

I'm thinking along the same lines as Lenny. Wondering if the OP has heard of one before or not?

Engineer54 · Oct 23, 2011

If there is and earth connection to this unit, then it's definitely a VOELCB, if not , then it's a very early ELCB. In both circumstances it should be removed, as this unit is well past it's useful life expectancy!!!

polo1 · Oct 23, 2011

Agree, a VOELCB, and I would not be leaving it in. What's the consumer unit arrangement? I would probably be covering the system with a new front end 100ma rcd, if the CU is as old as the VOELCB!

Knobhead · Oct 23, 2011

Either a VOELCB or a 300 / 500mA RCCD, both Crabtree units looked similar. You need to look if there’s an earth in and out of the unit inside the housing if there is it’s a VOELCB.