Outside socket for builders

[FarmerJon79]

I'm considering installing an outside socket for some upcoming building work.

Given that the house will be locked while they are building, what would you suggest for RCD protection?

I am thinking along the lines of an RCD protected MK Masterseal 13A connected to a metal adaptable box with SWA butted up to the CU and installed on a dedicated MCB on the non-RCD side.

Thanks

 

[Spark123]

Something like that would probably do, though to do it professionally I'd install a blue commando type socket with RCD and overcurrent remotely, fed from a slightly larger MCB inside. That way when they overload it and trip it out they can get to it to reset it. That or do the same as what you were going to do but use an accessable garage CU. Preferably I'd install it somewhere like inside an outhouse - I have seen some of the stuff builders work with and know of their respect for electricity!!
What type of supply is it, TN-S or TN-CS?
Should also note that this work will be notifiable under part p of the building regs.

 

[FarmerJon79]

Don't worry, I won't be doing the work, still at the quoting stage with various sparks who seem to be overrun with work...

Not sure on the supply type, have been meaning to write a letter to the DNO to confirm.

I don't have an outhouse, so can't put anything there, and although I realise that a commando would be ideal I'm aware that a domestic builder might not have these on their 110v transformers.

 

[sparkyspike]

I'm aware that a domestic builder might not have these on their 110v transformers.

16A - 13A adaptors are easy enough to come by. Or you can make one up.

 

[ban-all-sheds]

Not sure on the supply type, have been meaning to write a letter to the DNO to confirm.

It'd be quicker to look at the diagrams here: //www.diynot.com/wiki/electrics:earthing-supply-types-and-bonding and compare them to what you've got, or post a photo..

 

[FarmerJon79]

Well the honest answer is that when I moved in there was no earthing arrangement at all. I have used a pipe strap to lash an earth onto the incoming cable, I know this is wrong and I should have probably installed a TT supply.

I am empecting to have the entire house rewired in the next month by a qualified spark, so all this will be sorted.

 

[ban-all-sheds]

I have used a pipe strap to lash an earth onto the incoming cable, I know this is wrong and I should have probably installed a TT supply.

Yes it's very wrong. And you knew it was wrong, so why did you do it?

And have you measured Ze to see if it's actually providing an adequate earth, or might you have risked damaging the cable and causing a fire and got no benefit in return?

I am empecting to have the entire house rewired in the next month by a qualified spark, so all this will be sorted.

Ask whoever is doing it to come and spend a couple of hours asap to get your earthing sorted out - don't leave it until the rewire unless you have to.

 

[plugwash]

16A - 13A adaptors are easy enough to come by. Or you can make one up.

But what are the chances that such an adaptor owned by a builder would be IP rated.

 

[FarmerJon79]

FarmerJon79 wrote:
I have used a pipe strap to lash an earth onto the incoming cable, I know this is wrong and I should have probably installed a TT supply.

Yes it's very wrong. And you knew it was wrong, so why did you do it?

Let me rephrase that, I *now* know that is not the ideal situation. In my defence this was what the guy who installed my CU said I should do.

Before you shoot me down again, he is a friend of the family and was a highly qualified spark, rated for runway lights and other specialist kit. unfortunatly I had not realised that he was somewhat behind the times on the new regs, around 15th/16th I think.

Again in my defence all 4 of the sparks I have had round to quote on my rewire have looked at the earthing and said "looks OK".

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sparkyspike wrote:

16A - 13A adaptors are easy enough to come by. Or you can make one up.

But what are the chances that such an adaptor owned by a builder would be IP rated.

This would be my concern, that you end up having a non IP rated junction by putting in an industrial connector which then needs a convertor.

All advice is gratefully received

 

[RF Lighting]

If it's only temporary, what about a 6mm² from the board on a non RCD'd 40A MCB run surface in trunking or tube.

Use this to feed an IP rated CU.

In there, fit 2no. 16A RCBOs.

Use each of those to feed a twin masterseal socket.

 

[seasickstevie]

I don't have an outhouse...

What! A farmer without an outhouse?

 

[FarmerJon79]

I don't live on the farm. I commute.

 

[Spark123]

So it's you that holds up all the traffic every morning commuting to work in your tractor