Square D MCB to RCBO

Marcus Vaughan · Nov 8, 2018

Hi All,

I have just been to to view a job on my way home. The customer is asking for a new double socket immediately below the consumer unit (that's convenient!).

It's an old Square D board without an RCD in sight.

I guess it would be very easy to install an RCD socket outlet - spurring from either the kitchen ring or 'main ring' one way or the other.

But I was thinking - probably for the same price - I could swap out the MCB for an RCBO, though it would be second hand, but with the obvious benefit of providing additional protection for an entire socket circuit.

I thought of suggesting a board change - but that seems a bit OTT when a customer on a budget only wants an additional socket.

Question is then - what would you do?

Perhaps its not viable anyway - the MCB's are marked up as Dom, eg Dom32B6 - so am searching the web to see if a replacement RCBO even exists (by Square D/Schneider)...........

buzzlightyear · Nov 8, 2018

telectrix said:
don't forget that the main switch is arse about face.

well spotted .

telectrix · Nov 8, 2018

that's how it's designed. busbar is cranked behind the N.

Marcus Vaughan · Nov 8, 2018

telectrix said:
that's how it's designed. busbar is cranked behind the N.

I’ll look out for that - Thanks.

123 · Nov 8, 2018

Murdoch said:
MK seem to fit nicely .............

MK MCB is turned off though

I'm guessing that the electric shower got ditched.

Marcus Vaughan · Nov 19, 2018

I thought I’d close out my own post properly.

I returned to site and removed the evil MK MCB (which actually seemed to fit OK). It was - as was suggested - an abandoned shower supply.

In its place I put an Easy 9 RCBO - put the kitchen ring on it, as well the FCU and socket the customer wanted (there is going to be a worktop between the two).

The RCBO fits perfectly, though is a tad bulky, and I would not want to try and squeeze one in a congested board.

All good.

Thanks to those who contributed.