Power to outside shed

[ban-all-sheds]

If I were to tell you the SWA will be 4.0mm would you still use your suggested method of termination at both consumer units using adaptable boxes as close as possible to the c/units.

Yes.

To keep costs to a minimum, would you make the SWA/T & E connections on the inside of the garage

Yes - terminating inside means internal SWA glands and no need for waterproof boxes - ordinary galvanised or BE adaptable boxes will do.

then run T & E the 5m or so to the house c/unit or run the SWA up to the house c/unit then use your prefered conection method of adaptable box.

I assume that the garage is integral to the house, so the cable from outside enters the building there, and then runs to the CU at the other end of the garage?

T/E would be fine for that, if you are that desperate to save £4 or so. Or even less - a garage is probably an area where you should protect surface T/E with trunking or conduit, so by the time you add the cost of that in....

 

[Andy Fenn]

Point taken BAS re: once the cost of trunking/conduit is added I may as well run the SWA as close as poss to both the c/units.

And yes, you are correct with your assumption that the garage is integral etc.

What are your views re: which RCD side to use, the house or a new RCD c/unit for the shed.

What is a BE adaptable box please?

Many thanks.

 

[mapj1]

If you can afford two RCDs, it is wise to make sure that a fault in the shed cannot cut power to the house - avoids loss of freezer contents if a mouse chews cable in the shed while you are on holiday...
An adaptable box is really just a metal box with ready knock-outs - screwfix do one for example for a couple of quid. Its a bit easier than using a normal doubel socket back box and blanking plate, as there is more room (about twice as much)
My recommendation is not to use SWA on a plastic box if its your first go with the stuff - the tail wags the dog rather, and the thinner plastic boxes can crack as the unions take up the off-axis strain.

As regards PP, I direct you to the statute of limitation on non-inditable offences, such as breach of building reg procedure. It is 6 months (sec 127 magistrates court act). If you are not in the magistrates court within that time, you have got away with it, unless there is a later accident - which ther won't be if you have done it properly.
The same clause lets lots of asbo breakers and minor drugs offendors walk, and if the courts haven't got the time to fit them in, I cant see them queing up tp try us for the odd diy wiring job, unless its a truely appalling one.
It would of course be foolish of me to suggest deliberately breaking the law, but I could point out that if you do a good job the penalty is amost nil, and if and when you need to sell up, you can always get the lot (old and new) surveyed anyway

 

[ban-all-sheds]

What are your views re: which RCD side to use, the house or a new RCD c/unit for the shed.

Definitely non-RCD side at the house, feeding a CU with RCD at the shed end.

What is a BE adaptable box please?

Black Enamelled:

 

[Andy Fenn]

Thanks for the replies.

BAS, spoke to a leckie with over 40yrs experience today and his view was to take the supply for the shed from the house RCD side and his reason was to protect the SWA feeding the shed CU.

Appears to make sense to me but you can see why I get so frustrated when different leckies have different views.

What are your thoughts???

 

[Steve]

SWA doesn't need RCD protection. The outlets at the shed do.

 

[ban-all-sheds]

Crafty's right. The SWA itself does not need RCD protection, and by putting RCD at the shed end you get the protection you need there (which you still would if you came off the house RCD side), but what you do not get is:

1) A fault at the shed knocking out the house

2) A fault at the shed requiring you to go back to the house to reset the RCD

3) If you are indoors, a fault at the shed requiring you to go out to the shed to clear it before you can reset the house.

The problem with electricians with over 40 years experience is that some of them have not had an original thought in over 40 years....

 

[Andy Fenn]

BAS,

The more I read your comments the more I'd like to work and learn from you-thanks.

Would you agree to a 32A MCB for 4.0mm T & E connected to SWA 4.0mm supply from house c/unit to RCD shed c/unit.

Thanks.

 

[ban-all-sheds]

Provided the cables are not run in insulation, that will be fine.

What will be the length of the T/E, and the length of the SWA?

 

[Andy Fenn]

The SWA is about 23m and the T & E is no more than 10m running along the inside of the integral garage to the house c/unit.

Will the metal clad shed c/unit be ok to connect the SWA directly to or would you recommend still connect to some form of metal box first.

Many thanks.

 

[ban-all-sheds]

I make that 0.332 ohms for R1+R2, so that's OK.


I suggest you get 2 metal boxes - they don't cost much, do the one you need at the house end, and based on your experience of that make a decision on whether you can take the other end straight into the CU.

No reason not to, if there is the room.