Replacing consumer unit - dual RCD vs full RCBO?

Haggisman · 15 Jul 2021 at 14:14

Looking at replacing our ageing fuse box with a more modern CU (since fumbling around with fuse wire in the dark is not fun, never mind having a small child who is getting to the age where he is going to start putting things into sockets).

We have 6 circuits - up and down lights & sockets, plus electric shower and another one I'm not sure of. Is it worth paying the extra for full RCBO? If I understand correctly, it's no safer - more just a convenience thing?

Edit: sorry, should have included, so far we've been quoted £450 to do it with a dual RCD, and ~£200 extra with full RCBO, so it's almost 50% extra

Haggisman · 15 Jul 2021 at 17:12

NoobCannon said:
Prob a good idea to teach your kids not to stick stuff into plug sockets regardless of the type of cu, relying on a piece of equipment is a stupid thing to do.

WARNING: THIS POST MAY CONTAIN SUBTLE SARCASM. IF YOU ARE EASILY OFFENDED (OR JUST A LITTLE BIT "SLOW"), PLEASE LOOK AWAY NOW!

That's a good point actually, and an option I hadn't considered. Would certainly be cheaper than getting the CU replaced, and would also save a few £ on the lengths of copper wire I was planning to give them after showing them how important it is to push the sprung flap on the earth pin out of the way first

WARNING: THIS POST MAY CONTAIN SUBTLE SARCASM. IF YOU ARE EASILY OFFENDED (OR JUST A LITTLE BIT "SLOW"), PLEASE LOOK AWAY NOW!

Haggisman · 15 Jul 2021 at 19:10

NoobCannon said:
what is this even supposed to mean. “Its ok kids stick what you like in the socket just don't stick anything in the earth at the same time” what a stupid thing to say.

*whoosh*

Try again :cry:

Haggisman · 16 Jul 2021 at 10:45

BUDFORCE said:
To be fair, he did forget to put the OCUK sarcasm warning beforehand lololol.

Well, maybe his parents should have taught him to avoid sarcasm in the first place. Relying on a piece of text to protect him is a stupid thing to do. Anyway, apologies, I shall go edit my post

Thanks for the replies on both sides. I'm definitely edging towards the dual RCD setup, purely because the huge difference in cost doesn't seem to provide value for money in terms of the benefit. If it was 10-20% more then sure, but almost 50% is a significant chunk and could almost certainly do more good elsewhere.

If I'm understanding it right, the only difference with dual RCD would, e.g. a socket downstairs causes it to trip, we'd lose the upstairs lights as well, and vice versa, whereas with individual RCBOs it would be just the downstairs sockets which went down?

Haggisman · 16 Jul 2021 at 12:01

the-evaluator said:
Essentially yes, but it depends on the layout. If the downstairs sockets and upstairs lights are on the same RCD then a fault on the sockets would kill power to everything on that RCD including the upstairs lights. Circuits hanging off the other RCD woiuld not be affected so if the upstairs lights and downstairs sockets were on different RCDs then a fault on the downstairs sockets wouldn't impact the upstairs lights.

Cool, thanks - the electrician said he would set it up so we'd always have either sockets or lights both up and down, so we could e.g. plug in a lamp or so for some light