Adding an RCD to a consumer unit

[WozzaW]

Hi, I'm going to be installing an electric shower and wanted to know what RCD/RCBO I should order. MY consumer unit is a Square D QOS-6. I don't know any more about the unit other than one of the existing MCBs has "Type 3 M6" printed on it.

I want to order a 40Amp RCD or RCBO, but what should I be looking for, or will any Square D one fit ?

FYO. I'm fitting an 8.5Kw shower using 10mm2 cable. The shower is just the other side of the wall from the consumer unit, so the cable run is likely to be less than 1 metre (which is nice).

I would really apreciate any help.

Regards,
Tony.

 

[Aragorn84]

http://www.toolstation.com/shop/Ele...re+D+RCBO++40A+30mA+Type+B/d190/sd2615/p99547

 

[VanSolo]

Those rcbos don't fit the qos board.
Most electrical wholesalers can get hold of the one you want but make sure you're sitting down when they give you the price

 

[WozzaW]

Thanks guys for your quick responses. I didn't really want to pay that much. Would it be OK to install an MCB rather than an RCD or RCBO?

 

[Aragorn84]

Does the board already have RCD protection?

The shower must be RCD protected, so if the board doesnt have it already, then you need an RCBO, if it does (and the shower is going on the RCD side if its a split board) then an MCB will be fine.

 

[WozzaW]

Thanks Aragorn84, yes it does already have an RCD.

Final question, can you point me in the direction of the appropriate MCB for my consumer unit.

Many thanks.

 

[mfarrow]

Thanks Aragorn84, yes it does already have an RCD.

30mA ???

 

[WozzaW]

Thanks Aragorn84, yes it does already have an RCD.

30mA ???

Hi mfarrow, not sure what you mean?

 

[Spark123]

Can you upload a photo of what is written on the RCD?
I suspect a QOE type MCB will fit.
Also please note that this work is notifiable to your LABC under Part P of the building regulations.

 

[LiamPope]

Might be a good idea to consider what's already on the existing RCD before sticking an additional 40A MCB on it.

Liam

 

[Taylortwocities]

Tony, the work you are considering needs a lot of expertise.

As you don't know what the relevence of 30mA is then, with respect, I would suggest you don't have the necessary competence.

There are legal aspects to this work. See //www.diynot.com/wiki/electrics:part_p:diy_electrical_work_and_the_law

and also practical safety issues.

Do consider getting registered electrician in to work with you.

 

[mfarrow]

Hi mfarrow, not sure what you mean?

There are two common varieties fitted to consumer units: 30mA or 100mA. Look on the RCD itself and see what rating yours is. It may be slightly cryptic like 0,03A.

 

[WozzaW]

Cheers guys for all your help. I've done this kind of work before, but not since the new regs came into place in 2005. So I think the best bet is to find a local electrician and get him to do the electrical part of the job.

Many thanks,
Tony.

 

[Taylortwocities]

.....but not since the new regs came into place in 2005. .

Good decision, especially as there were more new regs in 2008!!