Campervan Electrics Best Practice

[Banquo]

I am about to install the electrical system in my new campervan. I won't be using solar panels but will have a leisure battery and durite vsr, 12v sockets and usb sockets, led lighting and 12v fan initially with an inverter and a 230v socket and stereo system and battery charger to be fitted later. I will probably install a hookup consumer unit and socket as well. Can anyone definitively tell me the best wiring practice including fuse placement and so on? I only want to do this once! Thanks

[walt1984]

I was advised to fuse the split charge wiring at the engine battery and again at the leasure battery and earth both batterys to the chassis.
I would fuse the lights, water, sockets etc separate then if one fuse blows you dont looses everything.
Mine used to have a blade fuse box near battery under the camper seat/bed but now runs through a zig type unit from a caravan. It has switches and fuses for lights and water pump circuits, has a built in mains charger.

Sent from my P330X using Tapatalk

[dumper]

On mime I run all 12 v it is as above for the split change relay plus I have a master switch at the leisure battery and one at the main feed to the fuse box whitch is on the top shelf above the bed so if something does go wrong at night it is easy turn off the power

[Noctule]

First of all, make a wiring diagram so you know what you think you want. Use wire that is larger than what you would expect to use. If you think that you'll need 10amps for all your accessories then fit 17amp cable between the battery to the fuse box. This will help reduce voltage drop. Also fit spare wires, just on the chance you might want to fit more lights, sockets, etc. I'm thinking of running a length of 7-core trailer cable to the kitchen so that I can upgrade from just the tap pump switch to having lights, a clock and a fridge vent fan, all individually fused.

My system currently looks like this.

1. Voltage sensing relay.

Charges the leisure battery and runs the fridge when the engine is running. Each cable in and out of the VSR is fused at 15a. The green cable is on the permanent live from the VSR, and powers the step and sliding door lighting.

12v_system_1.jpg

2. Leisure battery (in engine bay)

The charging cable from the VSR is also fused at the leisure battery. The contact breaker and huge front to rear cable were already on the camper when we bought it (it a community minibus with a wheelchair lift). These are more than capable of supporting an inverter if needed. The battery is earthed on the chassis.

12v_system_2.jpg

3. Cabin Fuse box at rear of vehicle

It's one of those handy ones that work like a distribution board and have LEDs to let you know when a fuse has blow. Every accessory (lights, USB, water pump, etc) is individually fused.

12v_system_3.jpg

4. Cabin power box

Yes, it's one of those little decorative boxes found in shabby sh*t and free trade homeware shops. This contains the cabin isolation switch, USB and accessory socket, voltmeter, with space in the top for USB cables. The voltmeter is currently always on, but I may change that to a push to test switch so that it is not intrusive at night.

12v_system_4.jpg

There is no solar panel or mains charger yet, but they're easy to add in with the extra cables I've already put in place. I've already fitted a dedicated 240v socket for a mains charger when I get around to it.

I might also alter the leisure battery circuit so that the VSR switches two relays, one each for the battery and fridge. This takes the load off the circuit board in the VSR and (apparently) provides a higher voltage to the battery.

Mat

[Banquo]

13765923_10154270605921768_1956649722936058730_o.jpg

I'm going to basically use this as my wiring diagram- with omissions

[Noctule]

I'd found that one myself, and found it very useful.

There's always some contention as to whether the 12v supply for the fridge should be taken from the VSR or the leisure battery. Mine is taken from the VSR as it's a 3-way fridge so when running on 12v it's always on, which will drain a 70amp/hr leisure battery beyond usefulness in 6-7 hours. This can be got around by fitting the fridge with its own VSR from the leisure battery, ensuring that it only takes 12v when the leisure battery is taking a sufficient charge, say a 10amp mains charger. I believe that compressor fridges take much less power, but obviously can't run on gas.

Mat

[ake]

That's a pretty decent diagram, but as above, if it's a 3 way fridge then it needs a voltage sending relay

[dumper]

First of all, make a wiring diagram so you know what you think you want. Use wire that is larger than what you would expect to use. If you think that you'll need 10amps for all your accessories then fit 17amp cable between the battery to the fuse box. This will help reduce voltage drop. Also fit spare wires, just on the chance you might want to fit more lights, sockets, etc. I'm thinking of running a length of 7-core trailer cable to the kitchen so that I can upgrade from just the tap pump switch to having lights, a clock and a fridge vent fan, all individually fused.

My system currently looks like this.

1. Voltage sensing relay.

Charges the leisure battery and runs the fridge when the engine is running. Each cable in and out of the VSR is fused at 15a. The green cable is on the permanent live from the VSR, and powers the step and sliding door lighting.

12v_system_1.jpg

2. Leisure battery (in engine bay)

The charging cable from the VSR is also fused at the leisure battery. The contact breaker and huge front to rear cable were already on the camper when we bought it (it a community minibus with a wheelchair lift). These are more than capable of supporting an inverter if needed. The battery is earthed on the chassis.

12v_system_2.jpg

3. Cabin Fuse box at rear of vehicle

It's one of those handy ones that work like a distribution board and have LEDs to let you know when a fuse has blow. Every accessory (lights, USB, water pump, etc) is individually fused.

12v_system_3.jpg

4. Cabin power box

Yes, it's one of those little decorative boxes found in shabby sh*t and free trade homeware shops. This contains the cabin isolation switch, USB and accessory socket, voltmeter, with space in the top for USB cables. The voltmeter is currently always on, but I may change that to a push to test switch so that it is not intrusive at night.

12v_system_4.jpg

There is no solar panel or mains charger yet, but they're easy to add in with the extra cables I've already put in place. I've already fitted a dedicated 240v socket for a mains charger when I get around to it.

I might also alter the leisure battery circuit so that the VSR switches two relays, one each for the battery and fridge. This takes the load off the circuit board in the VSR and (apparently) provides a higher voltage to the battery.

Mat

Looking at your wireing you have got a lot of un shielded terminals on your wires if a live one falls off it can earth out and the wireing needs clipping back better and if possible the campervan wireing is better not rapped round or touching the van wireing if you do get a short it could damage the van wireing

[hectors-tranny]

Echoing above mostly, all positive feeds need to be fused appropriately as near to the positive terminals as possible to minimise unfused cable run. This includes positives:

from starter battery to split charger
from leisure battery to split charger
from leisure battery to leisure distribution/fuse box

You also need to make sure you use the correctly rated cables for everything, and as a rule of thumb your fuses should all be rated at half or less than cable ratings, e.g. 20A cable should be protected by 10A fuse or less.

I bought my stuff here. They were helpful in ensuring all my fuses/cables were the correct ratings. https://www.12voltplanet.co.uk/split-ch ... asure.html

As you say you don't want to do anything twice! I was dead careful and used over-rated cables for the runs to all my electrical devices, housing everything in plastic conduit. I even put double conduit in short sections where it might rub, and minimised rubbing by securing with cable ties.

You will want a mains charger, so I would advise you install a 240V system from the word go. A garage consumer unit is fine, one 13A circuit for a couple of 240V sockets, and one 6A circuit for the charger. Make sure you use 2.5mm 16A cable and NEVER use non-flex in a vehicle. Again, conduit is cheap so use loads!

[npjrogers]

Mk5 smiley based camper-van. New to us. Leisure battery showing full charge. Zig LED indicator not showing green or red. Where did I start? Checked that leisure battery was charging by testing with voltmeter.. OK. Checked behind Zig panel.. showing 3.9volts Leisure.. Car Batt not connected to Zig.. thats ok (Don't want to run Starter Battery down)
Answer.. Checked Leisure Battery terminal connections.. discovered the +ve was loose and dirty.. cleaned them both positive and negative.. now all good..
Diagnostic clue.. if both led’s are not lighting up there is a fault between the Zig and Leisure Battery. As there was 3 volts I knew it was not open circuit so had to be either earth fault or Battery Terminals..
hope this saves someone from a sleepless night of worry.
Happy camper