TT RCD

[JohnW2]

Yes, All RCBOs exept one MCB. So I can do away with the RCD? I was told that I would need a 100 or 300ma RCD to protect from fire?

Sure, your 30mA RCBOs will be far 'better' at that than a 100mA or 300mA RCD, and the SWA will be adequately protected by the MCB, and doesn't need RCD protection. I suppose the only potential issue is the matter of how the 10mm² cable within your house is installed - it could be (e.g. if buried) that it would theoretically require RCD protection, which would open a little can of worms.

Kind Regards, John

 

[ban-all-sheds]

I was advised that I should not export the earth from my house and to TT it at the shed.

I was told that I would need a 100 or 300ma RCD to protect from fire?

Who's been telling you these things?

 

[Taylortwocities]

Who's been telling you these things?

It's probably the urban myth. It gets around a lot you know

 

[riveralt]

Is there a reason you are installing a standalone TT system in the shed. Does it have an extraneous conductive-part such as a metal water pipe?

I was advised that I should not export the earth from my house and to TT it at the shed. Plastic water pipes and timber frame.

Who by??

This is an old iet article but the principles still apply:
http://electrical.theiet.org/wiring-matters/2005.cfm

Download the section on electrical installations outdoors: a supply to a detached outbuilding.

 

[JohnW2]

I was advised that I should not export the earth from my house and to TT it at the shed. Plastic water pipes and timber frame.

Who by?? This is an old iet article but the principles still apply:
http://electrical.theiet.org/wiring-matters/2005.cfm[/QUOTE]
To be fair, it's probably worth pointing out that this is a much-debated issue and that a good few electricians appear to be less than fully happy about exporting PME earths to outbuildings.

The IET article presents local TTing and exporting of a TN earth as the two possibilities, without any discussion of the pros and cons and without indicating any 'preference'. They also only talk about earthing systems at all in the context of outbuildings which have extraneous-conductive parts (like metal water pipes), leaving it not totally clear as to what they are suggesting/proposing about earthing in situations (like the OP's) in which there are no extraneous-c-ps. I suppose that, by silence on the issue, they are implying that one should simply export the house's earth (whatever type it may be) in that situation?

However, as I and others have suggested in the past, issues comparable with those arising because of the presence of an extraneous-conductive-part can, and often do, exist in the absence of an extraneous-c-p in the outhouse - for example, if (as is quite common), there is a metalclad light switch just inside the door, which can (and often will) be touched by someone standing on ground just outside the building (possibly with bare wet feet) - or if there are Class I light fittings with exposed-c-ps on the outside of the building. The risks are undoubtedly extremely small, but seemingly no smaller than those which would be posed by the existence of an extraneous conductive part within the building. I am therefore not convinced that the presence/absence of extraneous-c-ps is necessarily the whole of what (should) needs to be taken into consideration.

Kind Regards, John

 

[riveralt]

The OP has been a little bit short on the facts regarding this particular question - his advice appears to have come from:
//www.diynot.com/forums/electrics/supply-to-poultry-shed.368058/

I'm out!

 

[JohnW2]

The OP has been a little bit short on the facts regarding this particular question - his advice appears to have come from:
//www.diynot.com/forums/electrics/supply-to-poultry-shed.368058/[/QUOTE]
Oh, good grief - your memory for names is obvioulsy better than mine. There are clearly 'shed and sheds'!

I'm out!

Sounds wise.

Kind Regards, John

 

[Oxia]

The OP has been a little bit short on the facts regarding this particular question - his advice appears to have come from:
//www.diynot.com/forums/electrics/supply-to-poultry-shed.368058/

I'm out!

What difference does it make what other posts I have made on the forum... this is a new question!

Answer it or dont answer it, up to you.

 

[EFLImpudence]

 

[JohnW2]

What difference does it make what other posts I have made on the forum... this is a new question!

Yes, it was a different question - and I think that, in terms of what you originally asked, it has been 'well answered', hasn't it? However, on the assumption that it's the same building you referred to in the other thread, in subsequent discussion here, you 'spared us' the fact that the 'large shed' was, in fact, a poultry shed - which could have some bearing on what people had to say.

Kind Regards, John

 

[RF Lighting]

This is a DIY website.

We don't give advice to buisinessmen trying to botch a commercial installation by doing things on the cheap.

Have you heard of / read the electricity at work regulations?

 

[Oxia]

This is a DIY website.

We don't give advice to buisinessmen trying to botch a commercial installation by doing things on the cheap.

Have you heard of / read the electricity at work regulations?

buisinessmen? I am not any form of buisiness! Private land, private house and all i wanted was advice. Enough said now as the job is now done. Thanks for all your replies.

 

[securespark]

You're a very naughty boy!

 

[RF Lighting]

Thats a heck of a lot of pets then

Pretending this is a run of the mill domestic DIY job doesn't actually make it one. It is a special commercial installation, and needs to be designed, installed, tested and certified by an experienced commercial electrician.