Caravan charging point / 16A Socket

uksparks · Feb 27, 2014

Hi,

Customer wants me to fit him a 16A socket so that he can plug his caravan in, PME supply.

I wouldn't call his drive way a caravan site, so not exactly sure if I should be doing this as it could be potentially dangerous as I was just planning on hooking up the earth as well, but then thought would it need a rod?

spark 68 · Feb 27, 2014

I would not connect the PME system earth to the outdoor socket, I would put that one socket on it's own 30mA RCD and on it's own rod.

The RCD would be incorporated with that socket, and the rod local to it. (fed from a non-rcd way at the house)

It is not so much that the garden is not a caravan park, but more the difference between 'true earth' and the PME earth, bear in mind the caravan body and chassis is bonded to the earth locally at the van side.

uksparks · Feb 27, 2014

Just thinking about this, it does clearly state in the regs that you don't take the earth to a caravan, which I knew.

I think I'll just tell him to stick with him after lead and plug it in to his 13a plug.

All I was going to do is change a faceplate for a commando socket basically for ease.

Whats the difference in having a proper socket or using an adaptor, the 13a plug version has the earth connected still, just I didn't do it.

uksparks · Feb 27, 2014

If the customer hypothetically said to me I want a 16a socket but don't want to tell e it's for a caravan then I wouldn't have known.... Just seems stupid how you can plug it in a 13a and it's all of a sudden aacceptable.

spark 68 · Feb 27, 2014

As I said if you earth the van with the PME earth, you would have a bloody big piece of metal (the van) that may be at a different potential to the true earth (the garden), then the usual broken suppliers Neutral scenario also rears it's ugly head, the car charging points regs are the same/similar for the same reasons.

uksparks · Feb 27, 2014

I think I'll just leave it...

spark 68 · Feb 27, 2014

Just RCD/TT that socket.

It is for safety reasons, just think if the Van body became live because of a fault, and you were stepping in or out., one leg on the garden and one leg in the van, it basically covers your arse in the unlikely event blah..blah

Engineer54 · Feb 28, 2014

spark 68 said:
As I said if you earth the van with the PME earth, you would have a bloody big piece of metal (the van) that may be at a different potential to the true earth (the garden), then the usual broken suppliers Neutral scenario also rears it's ugly head, the car charging points regs are the same/similar for the same reasons.

Except you can now use a PME supply for a car charging point!!

If this is just for a caravan battery charging point isolate the house earth and use a roded earth. I wouldn't be going overboard on the Ra values either, unless they intend to use that supply for anything other than charging the battery....

spark 68 · Feb 28, 2014

Engineer54 said:
Except you can now use a PME supply for a car charging point!!

It is not quite as cut and dried as that E54, there are a number of caveats attached to your statement above.

It is too much of a generalising statement to say you can use PME for car chargers, yes you can but only if other circumstances/conditions are met, ie. it is conditional. or you have a very good reason for the exemption clause.

uksparks · Feb 28, 2014

So just to confirm then, if this was TN-S then I could just go ahead and connect it up with no issue as its not PME and could connect the earth and take it outside to the caravan and thats all ok.

Engineer54 · Feb 28, 2014

That's correct, ....If it's a TN-S supply at the house, then No Problem!

Engineer54 · Feb 28, 2014

spark 68 said:
It is not quite as cut and dried as that E54, there are a number of caveats attached to your statement above.

It is too much of a generalising statement to say you can use PME for car chargers, yes you can but only if other circumstances/conditions are met, ie. it is conditional. or you have a very good reason for the exemption clause.

Point taken, i was aware, but to rattle off all those conditions/provisions and it would have been a hell of a long post. lol!!.

It's a shame the DNO's don't insist on the provision of an earth rod for all PME/TNC-S installations, as they do in most other Western European countries....

telectrix · Feb 28, 2014

you're saying that you can use PME to a caravan if you add a rod?

uksparks · Feb 28, 2014

As I understand it you can if you disconnect the PME earth.

The funny thing is, you could just get an adapter from a 16A to 13A plug top and plug it in on a PME anyway with no earth rod....

Do you feel that such adapters should be banned then.

spark 68 · Feb 28, 2014

UKsparks,

What you do is entirely up to you, we can only advise where you stand wrt regs, and why it is not a good idea to use the PME system earth for a caravan, whether it is in a park or the garden.

TT an TN-S supplies are no problem, it is only TNC-S/PME which gives problems on this type of install

Yes, you segregate the earths. here are the various drawings, although these are for full caravan pitches, the same principle applies to a single socket, Drawing 02 is the nearest one for your single socket, I have just included the others for information.