Caravan & Transportable Building Wiring Information

Caravan mains power wiring is a little different from other installations, classified as a “transportable” means it comes under its own AS/NZS Standard 3001:2008. This includes RVs, Campers and also Tiny Houses if they are on a trailer and they are to have mains wiring installed. Some of the usual requirements are as follows:

It is recommended that the inlet (male plug on the outside of the caravan) should be wired directly to an RCD (Type RCBO, 16 amp) replacing a main switch
Each final sub-circuit must have its own circuit breaker
All mains wiring must be separate and isolated from the 12 volt DC wiring
The wiring must be 7-stranded (usually 1.5mm minimum)
Wiring must be protected where it passes through the chassis
Wiring must be separated from any polystyrene insulation
The chassis must be earthed (use 6mm green conduit wire to the switchboard)
The maximum resistance from the earth pin of the supply lead plug to any part of the chassis = 0.5 ohms
If a backup mains supply (generator or inverter) is to be connected, a changeover switch will often be needed although it is possible to just swap plugs

There are also requirements regarding how the transportable is plugged into the supply via its supply lead:

Minimum supply lead length for caravan parks is 10 metres (no minimum elsewhere)
As a guide supply lead maximum length (1.5mm flexible cable) should be 25 metres
The socket outlet supplying the transportable must be individually RCD and overload protected and must have an isolating switch adjacent to the socket. This means it must be on its own circuit from the switchboard