Dodgy MCB

[jibjob]

Evening Gents,

While carrying out an EICR I came across 3 mcb's in the board that when switched off were still allowing up to 20/30 Volts into the circuit. Hob/oven circuit 32a, ring final 32a & shower 32a. The other 2 mcb's a 16a to boiler & 6a to lights were fine.
Mcb's are made by Schneider (Domae, Square D?) and probably installed in the last year or so. No paper available for any recent works done plus change of occupancy prompted me to instigate EICR.
Anybody else experienced this with this make of mcb's. I was going to give this a code 2.

Comments welcome.

 

[High Tower]

sounds like other circuits backfeeding. try measuring the 20ish volts and dropping each breaker off one at a time to see if it dissapears, failing that do a continuity test of the breaker in the closed position.

 

[Moses]

Evening Gents,

While carrying out an EICR I came across 3 mcb's in the board that when switched off were still allowing up to 20/30 Volts into the circuit. Hob/oven circuit 32a, ring final 32a & shower 32a. The other 2 mcb's a 16a to boiler & 6a to lights were fine.
Mcb's are made by Schneider (Domae, Square D?) and probably installed in the last year or so. No paper available for any recent works done plus change of occupancy prompted me to instigate EICR.
Anybody else experienced this with this make of mcb's. I was going to give this a code 2.

Comments welcome.

Did you remove the outgoing load cables, before measuring the voltages at the CB?

 

[telectrix]

and get yourself one of these.

 

[jdd]

In the con unit are the line conductors in very close proximity? (ie tie wrapped) This can 'induce' a voltage sometimes.

 

[Moses]

and get yourself one of these.

Tel

did you know they have brought new less chunky meters out?




LOL

 

[Knobhead]

Tel

did you know they have brought new less chunky meters out?

Pitty they don't work as well.

 

[Moses]

Pitty they don't work as well.

I think they do, if you pay the equivalent of model-8.3, for the new ones.

 

[Silly Sausage]

Have a read of this...View attachment Stray Voltage.pdf

Then have a look at this...
Fluke TL225. Buy online or call