If it is TT or TNS, you do not need to island the caravan and can just extend the house wiring as it is.
Although most UK DNOs advise that apparently TN-S supplies should be treated as if they were PME - since they often don't maintain neutral-earth separation within their network these days. The DNOs may occasionally guarantee a TN-S supply won't be PMEd but it's rare and usually reserved for things like big caravan sites or marinas - not something you're likely to find for a normal domestic supply.
If it is TT or TNS, you do not need to island the caravan and can just extend the house wiring as it is.
Although most UK DNOs advise that apparently TN-S supplies should be treated as if they were PME - since they often don't maintain neutral-earth separation within their network these days. The DNOs may occasionally guarantee a TN-S supply won't be PMEd but it's rare and usually reserved for things like big caravan sites or marinas - not something you're likely to find for a normal domestic supply.
