The following information is intended as educational
only, and will allow the DIY builder to source the parts required for a
240V electrical installation in a Recreational Vehicle. Government regulations
insist the installation must be done by a qualified electrician.
Left: 15amp Extension lead
The power supplied to an RV must be delivered by a 15amp
These are identified by a wider than usual earth pin, to prevent substitution
with a 10amp extension lead. The wire within the 15amp cords is rated higher
and allows for the flow of more electricity than a 10amp cord.
Modifying a 10amp cord with a 15amp plug should definitely
not be done. Even a 'heavy duty 10amp cord' should not be used.
Power Inlets come in different styles and different colours.
Insure you use one with a cover for external use, and rated
at 15amps. If you have more than one circuit in your RV, you will need extra
The connections at the rear must be covered and the Active
or Live (red or brown) and the Neutral (black or blue) wires should
then go directly to a double pole circuit breaker.
Left: Earth Connection
One earth wire coming from the power inlet must go directly
to the chassis and be connected with a Bolt and Nut and a Spring washer.
A second earth wire should then go to all power points, hard
wired appliances and any lights with an earth connector.
The wire should be at least 2.5mm and is normally green or
green/ yellow. (Shown above as white for easy identification in some photos).
Left: Circuit Breaker
You are legally required to provide (at least) a double pole circuit
breaker for each separate circuit in your RV.
These are rated at 16amps. RV's with air conditioners typically
have a second circuit.
Larger RV's with many appliances may even need three circuits.
Both the Active and Neutral go thru the circuit breaker,
so both are disconnected when the circuit is broken.
The Earth does not go thru the breaker, and must be uninterrupted
to each power point, hard wired appliance, and 240v light fitting.
Residual Current Device is a circuit breaker
with the added safety of cutting off the current when a leakage to earth
is detected from between HOT side and Neutral side.
A Circuit Breaker Cover is required to mount the
breaker in. It contains two parts - the rear rack and the front cover. It
is screwed to an inside wall or inside a cupboard. The breaker is then placed
in the rack and wires attached, the front cover secured.
Each hard wired appliance, and 240v light fitting requires
a double pole switch.
Some lights already have their own switch - it must be double
Switches are generally purchased with a cover as a complete
single or twin switch.
Even where a Range hood contains its own switch, an additional
isolating switch is required away from the stove top.
Left: Power Points
The power points we sell have double pole switches.
They can be connected in series (one after the other) with
the 3 wires terminating at the last power point.
Where the walls contain a cavity, you can generally use the
low profile power points. There are mounting plates and DEEP power points
also where there is a problem with wall thickness.
An external power outlet (eg in the annex) can be added to
The number of appliances connected to power points on one
circuit that are used at one time should be limited to the 16amps of the
Left: Wiring location
240V sheathed wire can run through the walls.
Where timber wall studs are 19mm square (photo shows a camper
trailer wall which are 42 x 19mm) some stepping or offsets should be used
to prevent wall being weakened along a straight line of drill holes.
Where aluminium or steel frames are used, grommets must be
used to prevent vibration wearing a hole through the insulation.
If not housed in a wall, all 240v wire must be in conduit.
240v wiring must not be under the floor.
Left: Outlets and switches
Backing blocks should be placed in wall cavities and all
wiring tested before cladding is installed.
It may be a good idea to take photos of wiring to ensure
no screws or drill piece wiring once the cladding is installed.
A registered electrician will be required to certify any
240v installation in a new motorhome. As government rules and regulations
can vary at any time, this information page should be read in the manner
in which it was intended. It is not intended as a replacement for a qualified