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Wiring for electrics
Posted: 12 Apr 2013, 21:20
by bowesy
I will soon be ready for wiring my van for electrics and I'm wondering what size/gauge of wire I require for the 12v side of things I have the wire for the 240v stuff I will be using a zig unit that came with my interior but as the van didn't have a camper interior I haven't got anything to go by
Re: Wiring for electrics
Posted: 13 Apr 2013, 10:28
by ghost123uk
bowesy wrote:I'm wondering what size/gauge of wire I require for the 12v side of things
You need to be more specific about what wires you are referring to. The charging and earth wire for the leisure battery (to and from the split charge relay need to be at least 40 amp rated. Then the ones for the interior lighting only need to be around 5 amp rated, ie a heck of a lot thinner

Water pump, around 5 amps too. Computer / TV feeds also around 5 Amps. Better of course to go a bit higher on the wire rating than lower
You should work out how much current is likely to be flowing in any given circuit and then roughly double it for the wire size (to give a safety margin).
Nowadays you can get aftermarket fuse box affairs (ebay) that are very useful. Mount it by the leisure battery and take your accessory feeds from it. Pretty essential bit of kit for safety, convenience and neatness.
Re: Wiring for electrics
Posted: 14 Apr 2013, 09:43
by bowesy
hi thanks for the reply i should have said what i will have running. i am going to use leds for the lighting i have a water pump with a switch on the zig i will also have the 3 way fridge hooked up to 12v and a few 12v outlets. i take it if im using 40amp wire for leisure bat then i shud use a 30 - 40 amp split charge relay
Re: Wiring for electrics
Posted: 14 Apr 2013, 10:23
by ghost123uk
Correct re the relay

- or go even a bit higher, 60 Amp, it won't cost much extra. A very dead leisure battery (you should never allow them to go dead though) can "pull" a lot of current from the vans main circuits when you first start up, only for a minute or less though, so a 60 amp relay is good. A 40 amp would probably do though.
Normal camper fridge pulls about 7 or 8 amps. Make sure you cannot turn the fridge on the 12 volt system unless the engine is running. It will flatten any battery in no time at all. Many split charge relays have a "fridge" out pin, or just use a separate relay triggered of the trigger wire on the split charge relay.
LED's can use that thin red and black stuff sold for wiring up standard car radios power.
DC outlets, if using "fag lighter" sockets (like I do) be aware that a laptop 12 volt input power supply can use 5 amps.
If using an inverter to get 240 volts, they can use a heck of a lot of amps, so the wiring for those will have to be appropriate to it's power rating. Even a modest 300 watt one can use up to 25 Amps.
Re: Wiring for electrics
Posted: 14 Apr 2013, 10:50
by Aberdeenbus
Hi
when I rewired my van I used here
http://www.vehicle-wiring-products.eu/V ... mepage.php" onclick="window.open(this.href);return false;
the wire pages give a guide for its usage and was pretty handy.
Cheers
Si
Re: Wiring for electrics
Posted: 19 Apr 2013, 19:39
by kentishvanman
Hi,
In addition to the help already given if you look in Wiki there is an Autosleeper wiring diagram.
That will give you a 'starter' on what cable sizes are used for the various items
Don.
Re: Wiring for electrics
Posted: 21 Apr 2013, 12:23
by nesty
I used 2x 75amp wire from my intelligent split relay to my leisure batteries, but inline I have 2 of those gold plated AGU fuse holders 50 amp for safety overload, which commonly used in high capacity ICE set ups.
Then from the leisure battery to a busbar fuse box which holds 12 blade fuse again 75amp cable.
I got all the cabling & bus bar fusebox from 12 V shop. I can't fault them, family business and fast delivery. I got a lot of stuff from them including my water filter system. I errored on the side of caution with wiring gauge, as I might want to put extra stuff on later on.
http://www.the12voltshop.co.uk/Shop/fus ... 5026b.html" onclick="window.open(this.href);return false;