Garage unit essential for a power supply?

Kingbroady · Jan 4, 2013

Hi.

I recentley had an electrician fit a power supply to my garage. The SWA goes straight into a metal double socket, rather than a CU. The supply does come from the house CU with a 32A MCB on.

Does this comply with the regs., please?

bigbaddave · Jan 4, 2013

What size cable is being used to feed this double socket, I personally prefer to put a seperate unit in the garage for the sake of £20 or so but if your feeding purly one socket in the garage is a bit overkill.. What is your Earting arrangments and is it RCD protected?

markc123 · Jan 4, 2013

So he's just spured off the CU for the garage socket....what size SWA is it, do you know?

...im sure theres a maximum length on spurs (granted that noone sticks too) but without getting my BGB out im not sure off the top of my head what it is, maybe 3meters?

telectrix · Jan 4, 2013

main query is RCD or not? at the source of the SWA or an RCD socket in the garage? untill this is known, we're unable to answer.

markc123 · Jan 4, 2013

Aye, one would presume it'd be an rcd socket if an actual sparks has wired it.

To be fair, if hes digging a trench for SWA for 1 socket, the OP may aswell of gone the full slog and got a little CU fitted instead, but thats up too him. A little more info king please, cheers.

Octopus · Jan 4, 2013

Think we should stop speculating and let the OP fill in the answers to the above....

DPG · Jan 4, 2013

Doesn't a separate building class it as a sub-main and therefore need an isolator at the garage end also? Daz

sparkol · Jan 4, 2013

This document: electrical.------.org/wiring-matters/16/elect-inst-outdoors.cfm is quite old but useful when dealing with wiring to outbuildings.

If the garage is detached and contains extraneous metal parts (e.g. a metal water pipe) then you should have a means of earthing, such as eqiupotential bonding from the main earth terminal.

As for whether to put a seperate db in, I've never heard of anyone not doing so - it just seems good practice, however I can't find anything in the regs saying you have to do it.

I'm fairly sure you can have any length of spur you want as long as it meets requirements for cable size, voltage drop, etc. I look forward to being corrected if I've got that wrong.