IS A CONSUMER UNIT WITH A MAIN RCD switch compliant

[MG201]

hello quick question. in a industrial setting would it be ok to fit a new consumer unit with a main switch RCD or do circuits need to be individually protected? wether there is only 2 circuits or 12 does this matter ? thanks for your time

 

[littlespark]

The concern is about selectivity, ie… a fault on one circuit does not create a problem across many circuits.

In a house, even with a duel rcd board, half the house is still working, and we try to design it so lights and power are shared across both RCDs.

You can still but consumer units with a mainswitch rcd, but tend to be smaller, non essential loads such as a garage or other sub main.

The other issue is with cumulative earth leakage… where many perfectly good devices cause a no fault trip, just because there’s so many.


You say industrial… but what would this board be serving, and is there a reluctance to rcbo each circuit. Some industrial circuits may not even require rcd protection… or indeed would be better off without it.


Ps, I’ll delete the duplicated question on the other thread.

 

[DefyG]

Not sure why you are asking, has a RCD main switch been specified? Is it an existing board?
It may be 300mA for fire protection or a time delayed version, which opens it up!

If for additional protection about 6 circuits per RCD I think is considered the maximum (ie 12 circuits split between 2x 30mA RCD's)