Static caravan domestic hook up.

[urbanmonkey]

Hi All, I'm new around here and already wanting to pick your brains! been having a discussion with another spark about a customer that wants to connect a static caravan adjacent to their house for their daughter to live in while she is at home. They already have an external power supply by means of a 32a switched socket, fed from the RCD protected side of their CU, less than 10m from the Cu and about 5m from where the caravan is to be sited. I'm of the belief that if they want to connect their caravan to this then the caravan must be TT earthed and the earth from the supply separated from the caravan. My colleague insists that as the caravan has no incoming metal pipework then it does not require its own system of earthing, as it would be treated as an outhouse. My understanding of the regs is that the caravan has to be earthed separately in case of a supply N+E fault potentially causing all its metalwork to become live? To complicate matters the customer informs us that they will also be disconnecting the caravan on occasion and using the socket for its original use to power a hot tub. He says leave the socket as is and wire a 32a plug from the caravan as normal to use for the supply. I think Earth terminal of 32a socket to be staked and provisioned as dedicated supply for caravan and customer informed that they require a separate socket for their hot tub? Who is right, me, him or are we both wrong??

 

[Marvo]

What's the existing house earthing arrangement?

 

[diditrain]

I would have a look at the hot tub supply type requirements

 

[Deleted member 9648]

The only requirement re-earthing system is that a TNCS earth shall not be used to supply a caravan and it would be usual to separate and TT if the supply is TNCS. A TNS earth is permitted. 708.411.4

 

[Engineer54]

The only requirement re-earthing system is that a TNCS earth shall not be used to supply a caravan and it would be usual to separate and TT if the supply is TNCS. A TNS earth is permitted. 708.411.4

Spot on, isolating/separating the original house earthing system from the caravan supply, only applies where PME/TNC-S is involved!!

 

[HandySparks]

OK. Should any socket on a TN-C-S system which may have a caravan plugged in be separated and converted to TT?

For example, a neighbour of mine has an MK Masterseal BS1363 socket on the side of his house. It's a TN-C-S supply, and the circuit is on a 30mA RCBO. He regularly connects his caravan, not for living in, but for keeping the battery topped up. If I was to do an EICR on the house, what should I recommend?

Why is a caravan is so different to any other piece of outdoor electrical equipment? Why aren't all outdoor sockets on a TN-C-S system required to be TT?

 

[telectrix]

nothing. because the hook up to the caravan is plugged in. it's not part of the fixed wiring.

 

[Engineer54]

nothing. because the hook up to the caravan is plugged in. it's not part of the fixed wiring.

You could say the same for virtually every caravan site hook-up, they are all via Plug & Socket....:dizzy2:

 

[Marvo]

I suppose it could be a gray area, if the customer requests an external socket for a hot-tub then who knows if they're going to use it for a caravan at a later date.

 

[urbanmonkey]

The house is PME, It was originally TT as its fairly remote and fed by overhead wires but the customer informs me that the supply was upgraded by UK power networks to TNC-S. So I think the way forward as the caravan will always be in its current position is to leave the existing socket alone and TT the caravan, breaking the link to the house earth by disconnecting inside the plug, making the caravan a standalone TT installation and leaving them with a PME protected outdoor socket to do with as they wish. I'm sure this makes any work we do as safe as possible and compliant considering possible future use of the outdoor supply.

 

[DPG]

Is disconnecting inside the plug a good way of doing it? I'm just thinking if someone moves the caravan in the future and doesn't realise. Just thinking out aloud, haven't really thought it through though Daz

 

[Richard Burns]

Fit a caravan hook up unit beside the existing socket, but independently earthed, and have the power to the hook up unit on a plug that can be plugged into the socket. Then if the hook up is not connected the socket can be for general use, if the caravan needs to be connected plug in the hook up unit and plug the caravan into the hook up unit.