Putting power to a shed

[Miles Reading]

Hi.

I am trying to figure out how to put power into my shed but really need some advice. The shed is about 15 metres from the house and will only need a lighting circuit to run a flourescent strip light,about 4 mains sockets to run an undercounter freezer and the usual shed power tools - drill, grinder etc etc.

Currently in the house we have a 1980's consumer unit with MCB's but no RCD - this is completely full. The electricity to the house is economy 7, if that makes any difference.

The plan was to extend the existing downstairs ring main via buried cable to the shed and in the shed, put one of those =A330 garage consumer units with a rcd and a 6 and 16 amp mcb. My questions are.....

How do I physically extend the cable outside, do I simply drill a hole through the wall next to the socket and feed the cable into the metal box through the side and connect the armoured cable to the terminals of the socket or do i need some kind adapter that goes from armoured cable to normal "indoors" ring main?

Once the cable is through the wall do I use that black plastic conduit as it would be about a foot off the ground, is that the idea of the round plastic boxes that they cover where the cable comes through the wall?

Additionally, it would seem that the shed end of the circuit would be the only section protected by an RCD, does this matter?

Thanks in advance for any help

[Owain]

You cannot take an unfused spur from your ring circuit as unfused spurs may supply only one single or double 13A socket.

You could take a fused spur, but that would limit you to 13A in total to the shed.

I think you would be far better splitting your meter tails with a 'Henley' block and fitting a 20A or 30A switchfuse at the house end. You can run armoured cable from that, or run T&E to a convenient location inside the house (underfloor void?) and change to armoured at an adaptable box. I suggest avoiding any external joints.

There is a calculator on the TLC website for sizing the cable to comply with voltage drop.

There are other matters to consider, such as earthing.

The work needs to be done to IEE Regulations and if you are in England and Wales, Part Pee of the Building Regulations applies and this is notifiable work unless carried out by an electrician registered with a Part Pee self-certification scheme.

Owain

[David Hansen]

On 26 Apr 2007 03:09:22 -0700 someone who may be Miles Reading wrote this:-

Not a good idea for many reasons.

Can you re-arrange the circuits in the consumer unit to get a spare way?

If not then a Henley block in the meter tails feeding a second consumer unit is probably the best option.

The wiring system to choose depends on the conditions and length of run.

15m from the house means that a separate local earth for the shed is desirable.

All this has been discussed on this group in detail, search engines will call up the discussions.