Electrician - Power to Garage, Advice Please

dan_l

Hi,

I want to have power in my garage and was hoping to get an electrician to do the job.
The problem is my consumer unit is an older type without a built in RCD so the way I was thinking for it to be done would be to have an external RCD for the garage.
I know people who have got it set up like this but with all the new regulations I was wondering if an electrician can still do this or would they only be allowed to do it if the consumer unit was replaced with one with a built in RCD?

Thanks,
Dan

SailorSam

I have the power going to the garage starting from a socket in the loft, and then going to the garage as a spur. I have a steel cable and hanging from it by loops is the electric cable, rather like a washing line.
When the house was rewired a few years ago they couldn't connect it back up again as it didn't meet the latest regulations.

fto

dan_l wrote: »

Hi,

I want to have power in my garage and was hoping to get an electrician to do the job.
The problem is my consumer unit is an older type without a built in RCD so the way I was thinking for it to be done would be to have an external RCD for the garage.
I know people who have got it set up like this but with all the new regulations I was wondering if an electrician can still do this or would they only be allowed to do it if the consumer unit was replaced with one with a built in RCD?

Thanks,
Dan

To be honest, its almost has cheap to replace your existing consumer unit............they are so cheap nowadays.

waynehayes

There's nothing in the regs that say you need a new board.

dan_l

Thanks for the replies. Is it just a regulation that the cable to the garage has to be RCD connected or could a cable just be ran from an unused trip switch on the consumer unit to the garage?

fto

Got to have RCD protection.........

Nilrem

IIRC when our garage was approved the plans called for:
RCD between the consumer unit (we're using what was a spare breaker with normal high ampage cable to the RCD) and the armoured cable.
Armoured cable buried and run out to the garage.

What we've currently got is that + a mini consumer unit (the sort with a pair of breakers and an additional RCD) in the garage to separate the line into lights/sockets.

I'm not sure what the exact specs are now, but it will require an RCD before the armoured cable I suspect, and an armoured cable, as normal cable may not be rated for external use (some is susceptible to UV breaking down the insulation/not waterproof), and is quite possibly likely to be attacked by squirrels etc, and that's before any chances of it rubbing/being hit with a spade etc.

I certainly would not suggest taking normal cable out any distance, especially without any protection (although having said that I have run an RCD protected extension about 4 foot out of the dining room to the shed via watertight conduit).

fto

There is two ways you can do this, one is to run a cable under ground which is a lot of digging, the other way is to run an overhead cable from the house to the garage. The cable should be supported by a strong wire ‘ called a catenary wire’ .

zax47

If you already have a Consumer Unit with circuit breakers (rather than fuses) then any single circuit can be RCD protect by replacing the MCB (Miniature Circuit Breaker) with an RCBO (which is an MCB and RCD combined), your electrician can advise on this but it's pretty straightforward to add an RCD protected external supply if you have space for another MCB/RCBO in your current box.

I can confirm, as others have said, that an external supply (whether to garage or shed or whatever) MUST be RCD protected.

Jonesya

I can confirm, as others have said, that an external supply (whether to garage or shed or whatever) MUST be RCD protected.

But does that RCD protection have to be located at the main consumer unit? If the supply is being run in armoured, could it be at a small CU in the garage - the cable wouldn't need RCD protection because of the earthed armour?

zax47

17th Edition requires all circuits for special locations (kitchens, bathrooms, outside) to be RCD protected regardless of the RCD requiring provisions (buried 50mm in fabric of building, etc.etc.etc.) affecting circuits for other locations. So yes, it should be RCD protected at source.

RCD in the garage is protecting the garage circuits, not the supply cable!