Running power to a caravan

[alnmcn]

Hi,

I am asking a question on behalf of my dad who is going to be starting a self build. He is going to put a caravan on site while the house is going up.

Question is what rating of cable should he use to feed the mains to the caravan?

The cooker, hot water and fire are all gas so it is really just appliances and possibly a small electric fan heater on the coldest days.

I know it will need to be SWA but am unsure of the rating.

Thanks.

 

[JohnD]

Probably 4mm for 32A. Dpends how long it is.

There are special rules for caravans and their RCDs and earthing.

With luck someone will have a link to it.

If not you may have to get a book.

 

[alnmcn]

The run length will be about 25m.

Would it be worth going up to a 6mm do you think?

Thanks.

 

[BJS_Spark]

Needs to be 6mm² SWA for 32A over that length and would be good up to around 37m.

 

[kevnurse]

At the risk of criticism I would say that, with the loads you've described for what is a temporary situation, a couple of 13A garden extension cables, carefully routed away from busy areas, would suffice.

 

[Lectrician]

At the risk of criticism I would say that, with the loads you've described for what is a temporary situation, a couple of 13A garden extension cables, carefully routed away from busy areas, would suffice.

Not a good idea, obviously.

Is there already power on site??

You need to determine the supply earthing type. If it is TN-S, you can wire as normal, if it is TT you need to ensure you use an RCD - A 30mA type would be most suitable here, and if it's PME (TN-C-S) then you MUST TURN THIS into a TT system to feed the caravan. You must NEVER feed a caravan with a PME supply.

 

[plugwash]

RCD wise, regs say that both caravans themselves and caravan park outlets should have RCDS, if you wire the SWA direct to the caravans CU though (and disconnect the inlet if present) then there shouldn't be any need to have the SWA on a RCD.

also the caravan should not be on a PME earth so you may need to use a rod.