wiring trailer 12v for camper

[boostin_7]

Ive recently purchased a Jayco Eagle camper & are wiring up an electric brake controller plus need to put a 12v source & thicker earth to power the fridge when in transit.
I really dont know how much the fridge would draw though & thus which way to wire it up.
I have twin 6mm cable running straight from the battery to the tub (ignition switched via relay with 50amp thermal breaker) which i plan on connecting a dc charger to later on for my second battery in the tub.

Would this power source be suitable to run the charger plus run the fridge in my camper when traveling? Or do i need to run another dedicated line to the battery just for the camper?

Any advice would be greatly appreciated

 

[04SilverSTR]

Run a dedicated line in 9mm twin to a anderson plug at that of your ute, the repeat into the van, make sure there is fuses both ends, also if you dont want to run you truck battery flat maybe chuck in a redarc smart relay or the dc-dc charger as well.

Bryan

 

[Old.Tony]

If that's 6 square mm cable then it's probably not heavy enough, although your fridge probably won't be too voltage sensitive it'll probably draw a fair bit - 15A for a small unit, up to 30A for the larger two-door fridges.

That sort of power over a long length of cable will cause the cable to heat up - not healthy. However, if it's 6mm diameter, that's about 27mm2 which is perfect.

How many amps does your charger produce? If it's a 15A charger (say) plus 20A for your fridge you need 35A towards the rear. 8Ga (21mm2) cable would handle both. I have a 25A charger (in the van), plus 30A for the fridge, plus 7A going into the tub - call it 60A total. I'll be relying on 8Ga cable for it - I'll see how it fares. I'm not going to run the fridge off 12V - I'm inverting the power, so that our fridge runs off 240V - it's more efficient, uses a thermostat and will switch itself off when needed. Under 12V it's just a constant drain.

I brought my heavy cables down beside the steering column behind the guard and along the top of the chassis rail, then up and over the rear shock mounts and across to an Anderson plug high up. I then made a Y-plug with one Anderson plug split to 2, with one leg for the trailer connection and the other heading up into the tub.

Time will tell how well it works. I am happy to go up to 4Ga cable for the long run from the front.

 

[boostin_7]

Hmmm ok..... if its 6mm dia is that measured across the whole cable (conductor & Insulator)?
I havent got the dc charger yet but I did find a book with the fridge specifics....it will draw around 15 amps on 12v & recommend min 6mm2 if wiring length is around 8m.
The power wiring on the campers trailer plug (jayco use the black wire on 7 pin setups for power source) which appears the same size cable as what ive ran to the tub.

 

[Old.Tony]

I usually talk about conductor size, because insulators can vary greatly - take a look inside jumper leads one day.

The recommendation for 6mm2 cable is not too bad but only because the fridge isn't overly sensitive to voltage. If you were using something with a compressor and a circuit (like an Engel or Waeco), their voltage-sensing circuit will barf very quickly on 6mm2 cable over 5m long. That's personal experience talking there - and I had a brand new Optima D31A spiral wound AGM feeding it. If you're ever likely to use a compressor-based fridge on the end of that cable, you should consider something a little heavier. I found the 8Ga cable quite adequate.

I changed to a 12 pin plug so that I could keep the 7 pins standard - allows me to just plug anyone's trailer on and expect it to work. I can get you the standard wiring for the 12 pin plug (includes fridge power and an earth line) but you might also consider an Anderson plug to provide separate power.

 

[boostin_7]

ok thanks your advice has been very helpful.
It looks as though the cable ive got is approx 3mm in conductor diameter.
Im unsure of what ive been given now as i walked into a 12v store & asked for 6mm cable plus a 50a relay & thermal breaker for it.

Ideally id like to run my camper fridge (15a), a cteck dc charger (20a), plus possibly my evakool fridge in the tub (4a assuming its flat out).

what size cable should be used that could handle upto 50amps?

Im also considering using anderson plugs like you've mentioned instead of the 7 pin plug

 

[Sundowner2]

Boostin, if you are buying a new Jayco product you will probably find it is fitted with a 12 pin flat plug, although 12 pin plugs have been around for a little while they are not yet common, the 12 pin plug has the five extra heavy gauge terminals (circuits 8 - 12) and is designed to eliminate the need to install a separate Anderson plug. In addition the 12 pin plug is also designed to accommodate the existing 7 pin flat plug making it useful across a variety of applications.

 

[boostin_7]

hi mate, shes second hand (2012) and has a 7 pin plug.
I spoke to Jayco & they use the black wire for the 12v power supply, which you can tell also because of the heavier gauge black & white earth wires.

 

[Old.Tony]

8Ga cable will handle 56A constant, so it'd be the one I'd look at.

 

[boostin_7]

Thanks Ill grab some tomorrow

 

[boostin_7]

So can anybody tell me what I was originally using & what amps that it could handle?
The conductor fits in the hole numbered 6 on my wire strippers & it appears to be about 3mm diameter to..
im thinking about runnng my 8 guage to a distribution block in the tub, then use this other wiring to go to the trailer plug & another to a ctek.