Caravan wiring

[Jarone]

Hey guys

Wiring in some dc aux power in a caravan which will be connected to the ute while towing

The van currently has ac wiring through it for when we're at a powered site. This is earthed to the chassis (I assume its an ac earth, yellow/green cable)

I am wondering if its a bad idea to connect the dc negative to the chassis as it will then share a connection with the ac earth

Will it be a risk if running ac appliances while connected to the car

 

[75 GRC]

The best person to speak to is 'old Tony'
OMG,that man has a wealth of knowledge about 12v applications..

Cheers
Geoff

"GO THE NAV V6's"

 

[Jarone]

Haha yes I've noticed

 

[Old.Tony]

Don't worry about 12V earth and AC earth. Two entirely different electrical systems that are unrelated - you can share chassis, because the 12V system doesn't (ordinarily) interact at all with the 240V system with one exception. The only (vital) thing that you need to do is ensure that if you use an inverter in your caravan, it MUST be "electrically isolated". The Powertech range (Jaycar, Rays Outdoors) is, but - surprisingly - the 600W units you can occasionally get at Aldi are also electrically isolated.

It's not even a consideration when you have devices that use both 240V and 12V (like a fridge). We had a Waeco CR140 fridge that would use 12 (or 24) volts when 240V was unavailable but when connected to mains it would automatically switch to 240V. I used that to my advantage - I fed 12V in to the van (while driving) and inverted it, supplying 240V to the fridge directly (via a relay that hopped between inverter-supplied 240V and mains-supplied 240V) and 240V to the C-Tek battery charger that was then able to charge a battery that had no load on it (resulting in a perfect charge every time). We had no trouble, no fires, no shocks, no damage - and I do the same in my tub too (to this day).

I invert power (while driving) to supply power (through an Aldi inverter!) to my 3-way fridge in the new van. I had to upgrade my relay from a 40A to an 80A relay because DAMN that sucker draws some power, but it works a treat without worry.

Do it, and enjoy.

 

[Jarone]

Sounds like a great setup

Cheers