Supply to caravan

americanpie

Running a supply to a caravan, there's a ring circuit of sockets and a lighting circuit, sub board in van has a 40 AMP RCCB, a 33 Amp MCB and a 5 Amp MCB.

supply is 50 metres away in a shed, so was going to run a NYMJ clipped along the beam inside of the shed then gland it into a metal junction box and continue outside the shed across the yard with a SWA.

Just wondering what cable would do, I'm thinking 6 sq, the major loads in the caravan will be a heater 3KW, and a kettle. And what protection would I need in the main board, would a 40 Amp MCB do the trick

Any help appreciated

M cebee

i think there's a section in the rules covering this type of work

i read it all a while back-can't remember much

you need a sparkie by the sound of it anyhow

Bruthal

M cebee wrote: »

i think there's a section in the rules covering this type of work

i read it all a while back-can't remember much

you need a sparkie by the sound of it anyhow

your almost as bad as me with that memory:)

Bruthal

americanpie wrote: »

Running a supply to a caravan, there's a ring circuit of sockets and a lighting circuit, sub board in van has a 40 AMP RCCB, a 33 Amp MCB and a 5 Amp MCB.

supply is 50 metres away in a shed, so was going to run a NYMJ clipped along the beam inside of the shed then gland it into a metal junction box and continue outside the shed across the yard with a SWA.

Just wondering what cable would do, I'm thinking 6 sq, the major loads in the caravan will be a heater 3KW, and a kettle. And what protection would I need in the main board, would a 40 Amp MCB do the trick

Any help appreciated

You might get away with 6 sq if you had a 20 amp MCB in the main board. And that might just about do the loads you have,
But a safer bet would be a 32amp MCB at main board and 10 sq to caravan. If you use a 40 amp at main board you will need 16 square to caravan for that size of breaker over that 50m run.

And what sort of supply is supplying the 'main board' in the shed? Maybe it is to small to allow a sub circuit at 40 amps anyway.

32 amp sub circuit with 10sq id say, and 32 amp rcbo in the caravan board instead of the 40.
As M cebee says, a job for a sparks anyway.

americanpie

I think it's 10sq supplying the shed from another board, will that manage with another 32 Amp supply taking off it?

think your right, I'll have to use 10 sq SWA for the whole run with a 32 amp at either end.

But should the 32 amp at the supply side be on the RCD or should I just leave an individual MCB

Bruthal

americanpie wrote: »

Yea think your right, I'll have to use 10 sq SWA for the whole run with a 32 amp at either end.

But should the 32 amp at the supply side be on the RCD or should I just leave an individual MCB

Like M cebee said too, i forget the actual regulations on caravans myself, but i would think the RCD would be better at the sub board in the caravan with a 32amp MCB at the supply end because the RCD is more likely to trip from nuisance tripping etc, and to go all the way to the board in the shed would be a bigger nuisance.

M cebee

ya -you won't be rcd'ing the swa submain at the supply side


the rules might require 30ma outside i'll check later or someone might know

Buford T Justice

20A MCB would be plenty for the load going to the caravan. Cable sockets on the outside of the Caravan are rated at 16A

Bruthal

Might be 5kw between the heater and kettle so 22.5 amps
20 might just about do it though. Most mobiles i seen had gas heaters in them.

M cebee

don't know much about this

asuming it's a permanent installation prob a DP main isolating switch/mcb and 2 DP RCBO's(with Zl within limits) for the final circuits