Electrics to Shed - dodgy advice?

[sam8364]

Hi,

I have just had a quote for isntalling electrics in my shed / workshop. But what he has said seems to conflict with some advice I have found online. Could anyone shed some extra light on the issue?

He wants to supply the shed with a spur off the ktichen sockets. The kitchen sockets are on a dedicated ring from consumer unit and we currently run a fridge freezer, washing machine, tumble dryer and dishwasher from them plus kettle etc.

In the shed I want to run a variety of appliances with 1000-1500w draw i.e. bench saw, pillar drill, router etc (only one at a time of course), plus a light and radio.

His proposal is take a spur off the kitchen with a dedicated RCD for the shed and a small fuse box in shed with a fuse for lights and one for sockets.

Is this a safe way of doing this?

Also, the shed is about 35m from the house and so he has specified 4mm 3 core armoured cable for the job. Is this ok?

Many thanks for any help with this - electrics are not my thing!

Cheers

Sam

 

[dingbat]

He wants to supply the shed with a spur off the ktichen sockets.

Not ideal, adding to the load of what is probably the most heavily loaded socket circuit in the house. Also, if this circuit is RCD protected it is highly likely that any fault in the shed will trip the whole circuit.

His proposal is take a spur off the kitchen with a dedicated RCD for the shed and a small fuse box in shed with a fuse for lights and one for sockets... Is this a safe way of doing this?

Dedicated RCD consumer unit in shed, good. Spurring this off existing ring, not so good.

Also, the shed is about 35m from the house and so he has specified 4mm 3 core armoured cable for the job. Is this ok?

For the expected load and the distance, 4mm would be okay, but I don't like the idea of spurring off a 2.5 sqmm circuit in 4 sqmm cable. And how will he earth the armour? And what if the load increases in the future? It might be better in 6 sqmm.

A better idea all round would be to run a complete new circuit from the origin of your supply, with the armoured cable properly terminated and earthed, to a metalclad RCD shed consumer unit.

Is there any reason he's trying to avoid the longer cable run? Difficulty of access, perhaps?

 

[sam8364]

It will be a bit of a pain to run a new cable through the house back to the consumer unit - but not impossible - just have to find an appropriate place for a hole in the wall. Then it is just the increased cost of the cable for the extra length.

Also all the fuse bays (correct term?) in the current consumer unit are used so it would mean an additional box on the wall - so increased cost.

He also claimed that as the shed was only an extention of an existing main it would not need a Part P.

Obviously I do not want to pay more than I have to but obvioulsy safety first.

 

[dingbat]

It will be a bit of a pain to run a new cable through the house back to the consumer unit - but not impossible - just have to find an appropriate place for a hole in the wall. Then it is just the increased cost of the cable for the extra length.

Which is negligible.

Also all the fuse bays (correct term?) in the current consumer unit are used so it would mean an additional box on the wall - so increased cost.

It is not a cheap job anyway. To do it properly I'd be looking at £3-500, depending on access.

He also claimed that as the shed was only an extention of an existing main it would not need a Part P.

Ah, so he's not registered. Is he going to test and issue a certificate? I somehow doubt , especially if that "would not need a Part P" phrase is a direct quotation. (New outdoor wiring is notifiable, by the way)

Obviously I do not want to pay more than I have to but obvioulsy safety first.

Fair comment, but in my experience customers usually take the least expensive option and to hell with safety.

Get a quote from at least one other electrician who is registered to self-certify. Try niceic.org.uk or napit.org.uk and do a contractor search for your area.

 

[sam8364]

The direct quotation was that it technically did not need a Part P as as it was only a fused spur and that he would not bother.

Correct, he is not registered.

This job was going to cost about £220 done his way. - But that was with me doing the work to bury the cable.

I know what you mean about going for the cheapest option - but I like to know thigs are safe - I also want to avoide a world of hassle when I come to sell the house.

Thanks for the advice.

 

[totallyspies]

(New outdoor wiring is notifiable, by the way)

Not nessecerily ....

http://www.screwfix.com/talk/thread.jspa?threadID=35412&tstart=0

 

[dingbat]

Totallyspies, see Approved Document P, Table 2

Note e: Conservatories and attached garages are not special locations. Work in them is therefore not notifiable unless it involves the installation of a new circuit or the extension of a circuit in a kitchen or a special location...

Note f: Detached garages and sheds are not special locations. Work within them is notifiable only if it involves new outdoor wiring.

I think you'll find that not only is the intention to extend the kitchen circuit, but also to run new outdoor wiring to the remote shed. This job is notifiable.

 

[sam8364]

Thanks Dingbat.

I will get on to a more reputable sparky and get a quote for doing the job properly.

 

[dingbat]

The direct quotation was that it technically did not need a Part P as as it was only a fused spur and that he would not bother.

It was the terminology that bothered me. Part P is a section of the building regulations; it is not a qualification a certificate or some form of permission. Anybody registered should know this and also understand what is and is not notifiable.

Should you come to sell you will be asked whether you have had any notifiable electrical work done since January 1st 2005. If you don't have a building regs compliance certificate you may find yourself having to explain why not and rectify the situation.

(Edit: Sorry, we seem to have been typing at the same time! )

 

[sam8364]

No problems

I have a list of the NICEIC Domestic Installers in my area and will be getting on to a couple later today.

You advice was much appreciated - stopped me making a costly and potentially expensive mistake.

What a shame that you have to double check what an advertised electrician says when he comes to give you a quote. Mind you, so far we have had the same issue over plumbing and windows. - You start losing faith Still must stop moaning......

Cheers dingbat!!!

 

[totallyspies]

I think you'll find that not only is the intention to extend the kitchen circuit, but also to run new outdoor wiring to the remote shed. This job is notifiable.[/quote]


Yes sorry, forgot the initial enquiry said kitchen socket.

However Part P applies to "fixed" wiring.

If you follow the instructions supplied to the letter you are not installing "fixed" wiring but essentially an extension lead, which happens to be made with SWA. And since Part P does not apply to extension leads it wouldnt not be notifiable. But yes, I agree if you extend a kitchen circuit using "fixed" wiring it IS notifiable.

You could of course use this special extension lead via a hard wired plug in RCD (which you buy as an addition to the kit) and plug that into ANY exsisting socket reguardless of its location, provided that the load isnt to high say under 1500-2000w.

If the load is gonna be in the 2kw or above I would suggest, as you do, a "proper" fixed wiring installation to cope with the load.


But remember Part P applies only to "FIXED" wiring.

 

[dingbat]

You can spend your time looking for ways around the rules or you can get on and do the job properly.

Clearly, building control are not in the habit of spot-checking homes, otherwise all manner of contraventions of the building regs would be found, but any electrician doing this work for profit would be a cowboy to install such an arrangement.

A visible, extension cable, in flex, plugged into an RCD-protected socket and run out to the shed on an as-required basis is one thing. But as soon as you start playing round with buried SWA feeding a consumer unit with fixed final circuits masquerading as an extension lead and try to argue that it's not fixed because it's supplied via a plug you are very clearly trying to work around your responsibilities.

Avoiding or evading? I'd rather not have to tread that line.

PS:

But remember Part P applies only to "FIXED" wiring.

As soon as the cable is attached to a structure it is, by definition, fixed. Flex can be fixed and the regulations do apply to any wiring systems and cables... and all consumer installations external to buildings. according to regulation 110-01-01

 

[totallyspies]

You can spend your time looking for ways around the rules or you can get on and do the job properly.

Yes I can. Properly? Which law says that what I have suggested isnt legal.

Clearly, building control are not in the habit of spot-checking homes, otherwise all manner of contraventions of the building regs would be found, but any electrician doing this work for profit would be a cowboy to install such an arrangement.

Why is that then? If this is a cowboys ways of installing why are they mentioned in the Part P doument as being allowed to work on?

A visible, extension cable, in flex, plugged into an RCD-protected socket and run out to the shed on an as-required basis is one thing. But as soon as you start playing round with buried SWA feeding a consumer unit with fixed final circuits

They are NOT final circuits, they are "prefabricated equipment sets" plugged into exsisting socket outlets and terminated with a socket outlet on the other end.

masquerading as an extension lead and try to argue that it's not fixed because it's supplied via a plug you are very clearly trying to work around your responsibilities.

Who said it has to be buried?

Why is it any more "safer" buried than visable. Whats safer a buried cable that you cant see or a cable you can see, that you are less likely to cut through as you can actually see it?

Work around responsabilities? No it IS allowed as it clearly says so in SI 2006/652.

And thats why these "prefabricated sets" are allowed to be installed and are non_noitfiable.

Avoiding or evading? I'd rather not have to tread that line.

No one says you have to. If you dont feel comfortable with that installation method, then dont use it.

 

[totallyspies]

[according to regulation 110-01-01[/quote]


But thats not law. Only regs. Which are guidance only.

 

[sam8364]

OK chaps, end of round 2.

So you can either do it to the spirit of the law / regulations and be confident that it is all above board and fit for purpose -- or you can interpret the wording to do it the cheapest and easist way and probably get away with it.

Personally, I like to go with getting it done in the spirit of the law and be sure even if it costs a bit more.

I appreciate all the advice. Cheers