What gauge of wire to choose and where to get it?

[TheBeaver]

Our camper is about to get a bit of an overhaul and this will involve new wiring throughout. To make sure I am not losing any time sourcing wiring after I start the project I was going to try and get it before hand. Does anyone have any rules of thumb for what gauge of wiring to use for the electrics in a camper? There is the 240v coming in the side, and the 12v leisure system running fridge, lights, water, music, and charging phones (no tv screens or the like).
Also any suggestions online of good suppliers for wiring?

Cheers

[bigbadbob76]

I'd use 2.5mm^2 3 core flex for the 240v stuff, it's worth putting in an RCD and a 10A breaker too.

I get my wire from work but VWP do a good range. http://www.vehicle-wiring-products.eu/
For your leisure battery and fridge I'd use the thickest wire you can,
6mm^2 or preferably 10mm^2 for your split charge relay power wires. relay coil wires can be thinner, 1mm^2 is fine here.
10mm^2 or preferably 16mm^2 from your leisure battery to your fuse box.
6mm^2 from fuse box to fridge
4mm^2 from fuse box to water pump
2mm^2 from fuse box to lights
2mm^2 from fuse box to phone charger
6mm^2 from fuse box to cigarette lighter socket if you have one.
Music will depend on your system, just a basic car stereo will get away with 2mm^2 but if you have a big amplifier you'll need some seriously thick wiring for that. in this case consult the manual and keep the cable run to the amp as short as possible.

You can get away with smaller than these but you'll get voltage loss with thinner wires especially on high current devices with long cable runs like the fridge.
Fusing and cabling everything seperately like this is good too and helps reduce voltage drop on the cables.
Hope that helps.
BBB.

[TheBeaver]

Wow, thanks Bob! That is fantastic!

[bigbadbob76]

Glad to help.