solenoid or relay for caravan wiring

gooday zacc
my opinion only but you are probably better off with the solenoid to carry the load
jmo
steve

Zacc
so you say when the vehicle is not running there will be NO POWER going to the fridge ??

Mainey . . .

Hi Zacc

I would assume it is a 3 way fridge so they draw around 10 amps.

Use either a solenoid or a good quality 30 or 40 amp relay to switch the load.

Make sure the wiring is also heavy enough to carry the load and you use a breaker or fuse on the circuit.

6mm2 cable is recommended.

Regards

Derek.

thanks guys for the advice , much appreciated

Zacc,

Another option, if you have the room, is to install a second battery in your van (go for a deep cycle). Wire up your fridge directly to this battery.

Then run the wire from your car battery, through an Anderson connector, to the battery on your van. This wire should be controlled through a solenoid. You can get a solenoid that has an inbuilt timer, set so that charge / current is not sent to the second battery for a period of time (usually about 5 - 7 minutes) after the car starts. This allows all of the charge from the alternator to charge the car battery first, before current is drained by your van battery / fridge.

Advantages of this include providing full charge to vehicle battery immediately after starting the car, the fridge will continue to run even when the car is turned off (you can install a separate switch at the second battery if you want to be able to turn power to the fridge off) and the fridge will not be subject to any variations in current / voltage when you are starting the car (one of the easiest ways to damage a fridge).

The solenoid with the inbuilt timer is about $130 - I bought one from Opposite Lock in Kalgoorlie last week as this is the way I am setting up the power for my camper trailer. You can also get much more elaborate set-ups if you want to spend the dollars, including dual battery controllers, charge indicators etc. But for a cheap and safe set-up which provides battery power to your fridge both when the car is running and stopped, and protects your fridge from voltage fluctuation, the set-up I have described above is easy, cheap and works well.

As others have already mentioned, whatever option you choose, make sure that you use appropriately rated cable and decent fuse protection.

When I'm setting up a system like this, I always run two cables - positive and negative. I take the negative cable back directly to the negative terminal on the car battery. If you're already running one cable, it's no more difficult to run two, and the Anderson plug is a dual pin connector. Some people have told me that this is overkill, but I believe that an independent negative or earth circuit in this application is the way to go.

Hope this helps.

Cheers ........... BM