Log cabin 6mm 4 core swa

[EFLImpudence]

All that plus the armour isn't much good at mechanical protection either.

SWA would appear to be not fit for purpose.

 

[ban-all-sheds]

Winston overlooks the problem that a fault in the cabin could trip MCB and/or RCD in the house leaving people in the house in the dark.

Winston overlooks every single thing which allows something to be done if he doesn't like it.

Why do you want a CU in the log cabin? Sockets can be run direct (using the MCB in the house) and lights via a switched FCU.

No required. As I said sockets direct (using MCB in house). Light(s) via switched FCU, and yes heater can be plugged into one of the sockets.

Sparcktikus - Winston is wrong - ignore him.

 

[ban-all-sheds]

It can be a problem. Assume some minor damage to the outer sheath of the cable allowing ground water to reach the steel wire.

OK - so you're going to start off assuming something already in contravention of the Wiring Regulations, and in England & Wales arguably illegal.

When the steel wire is connected to the MET in a PME system the steel wire will be at Neutral potential which may be a few volts different to the ground water in contact with the steel wire. AC galvanic corrosion will occur.

When the steel wire is connected to the MET of a TT system with a copper ground rod there will be a voltage generated from the cell created from dis-similar metals in electrolyte. Ground water being the electrolyte. DC galvanic corrosion will occur. Also happens if there is a lead water pipe or other metallic item that is buried and connected to the MET.

But even if not using it as the cpc, not earthing the armour is not an option.

 

[ban-all-sheds]

once you want over 13 amp in the out building either RBCO in house or CU in outbuilding, the option of a simple MCB in the house is only valid if supply under 13A so a RCD FCU in house or outbuilding can be used.

Incorrect - of course a larger circuit could be run to an outbuilding.

Were you correct then there could be no radials >13A inside the house either.

 

[bernardgreen]

OK - so you're going to start off assuming something already in contravention of the Wiring Regulations, and in England & Wales arguably illegal.

Do gardeners read a copy of the Wiring Regulations and thus know it is illegal to hit a buried cable with a spade. And I doubt moles can read anything

 

[chivers67]

The SWA in this instance is going to be terminated indoors, it should be buried deep enough that a spade won't damage it and tape over it as a double warning. Are Moles capable of chewing steel?

 

[bernardgreen]

Are Moles capable of chewing steel?

probably not but other rodents do gnaw through plastic cables. Sharp stones can puncture the sheath.

 

[scousespark]

So we return to a scheme member electrician working on your home, is more limited than your self

Why do you think a scheme member is restricted in what he can do? Do you believe a diyer gets a pass and can ignore the regs (given they are focussed on safety)? Btw, I am aware that you don’t need to comply with bs7671 to comply with part-p, but it is the simplest way to do so.

 

[ban-all-sheds]

Do gardeners read a copy of the Wiring Regulations and thus know it is illegal to hit a buried cable with a spade. And I doubt moles can read anything

Take your point.

But the armour still has to be earthed.

 

[scousespark]

Are you perhaps confusing winston and eric, since I cannot reconcile your comment here with anything that winston has posted in this thread? It was eric who, for reasons I fail to understand, was talking about limiting loads to 13A - as far as I can make out winston only mentioned an FCU (fed from the cirecuit supply the sockets) in relation to lighting, which seemed fair enough.

Kind Regards, John

No I have not confused posts. Winston replied to a post recommending a CU, saying to take the swa into a junction box and feed into an fcu. For a shed, that could be viable, but this is for a log cabin.

 

[JohnW2]

No I have not confused posts. Winston replied to a post recommending a CU, saying to take the swa into a junction box and feed into an fcu. For a shed, that could be viable, but this is for a log cabin.

I think I must be missing something, since all I've seen is ..

No required. As I said sockets direct (using MCB in house). Light(s) via switched FCU, and yes heater can be plugged into one of the sockets.

... no reference to a JB and, as I said before, he was suggesting that the sockets could be fed directly from an MCB at the house end, with an FCU for the lights (not to 'limit the load to 13A') fed from that. Obviously not the only way that it could be done, and perhaps not teh way that most people would do it, but I see nothing inherently wrong with that approach, do you?

Kind Regards, John

 

[sparcktikus]

Thanks for the replys and debate . After all that's why we ask the questions.
I will go ahead with my original plan of 4 core 6mm because of load requirements for cabin. I know the armour can be used as earth but myself personally i always use a conductor and dont solely rely on the armours earth, not for any reason inparticular because when they are properly made off it is a good secure connection . It's when they are poorly made off then there's a problem, take heed apprentices and diyers alike...

 

[donrkebab]

Just to be clear, you must earth the swa armour regardless of whether you also use a spare core for the cpc,

Also as I said earlier, have you considered the need for data/phone wiring.

 

[Notch7]

Just to be clear, you must earth the swa armour regardless of whether you also use a spare core for the cpc,

Also as I said earlier, have you considered the need for data/phone wiring.

Ive heard some people say earth at both ends, others say only only one end. Maybe that is dependant on earth type.

I wonder about the situation with earthing the armour when the earth isnt being exported, like a TT earth.

 

[EFLImpudence]

Ive heard some people say earth at both ends, others say only only one end. Maybe that is dependant on earth type.

It is.

I wonder about the situation with earthing the armour when the earth isnt being exported, like a TT earth.

Then it would have to be isolated at the cabin end.

It must be connected at the supply end to give protection (disconnect supply) when pierced by spades etc.