Van 3 way fridge power 12vdc or 240vac when driving.

Most run on 12 v as with an inverter you get losses through the circuit.

Also having 240v floating around in a car is not the safest thing to have.

Definitely NOT on Gas.

Run ours on 12 volt only when travelling
Cheers
Charlie

There are only 2 reasons I can think of to use 240V via an inverter while travelling...
1. If the 12V wiring is not heavy enough and therefore the voltage drop to the fridge is too high, or
2. The 12V heater coil in the fridge has burnt out and you are in an 'emergency' situation.

In you case, with 6B&S cable, your voltage drop should be fine - especially given that the voltage at the battery when you are travelling is greater than 12V (ie charging voltage of 14 - 14.3V).

As Graham has pointed out, running via an inverter introduces additional energy losses due to low efficiency in the inverter, and having 240V floating around is definitely undesirable.

I would disagree with Graham re running on LPgas though... I believe it can be done provided precautions are taken like turning it off during fuel filling etc. I wouldn't run on gas unless a real emergency due to safety and it is more expensive to run on gas than on 12V power.

cheers,
glids

Wayne,

Apart from the inefficiencies of converting 12v to 240v there is also the safety factor. There is an excellent article here about safety with electricity.

Cheers,

Val

Battery Draw with Fridge on 240 Volts

My Ultimate Camper Trailer 3 way fridge (Electrolux before they changed to Dometic) has a label just inside the door. It states that on 12 Volts the power consumption is 125 Watts. This is 125/12 = 10.42 Amps draw from your 12 Volt battery.

It also states that the power consumption on 240 Volts is 175 Watts. Allowing for an 80% efficiency in an inverter makes this 100/80 x 175/12 = 18.2 Amps draw from the 12 Volt battery when the fridge is run on 240 Volts.

Note that the efficiency of inverters varies considerably (70% to 95%) and depends on the load, just look up the data sheets before you buy one.

You will draw more current from your battery using the 240 Volt approach.

We have always run our vans on 12v whilst traveling.
We also know that the 12v element is not controlled by the thermostat hence the 12v element will be working at full boar all the time.
I have also noted that the 12v system for these types of fridges only really manage to hold the temp in the fridge (just). So as soon as we stop for any time over 5 minutes we run the fridge on gas whilst stationary then simply revert to 12v before we restart.
This has been our method on all four vans we have had.

I therefore suggest that you stick to running your van fridge on 12v whilst on the move.

IMHO running the fridge on 240 via a inverter can be fraught with danger in the event of an accident. Same for gas.

This seems to be the general consensus from the Caravaning fraternity.

Hi Wayne,

The problem with using an inverter to power the fridge on 240V, as well as the things others have said, is that whether it is in the car or the van it may not disconnect in the event of an accident.
This leaves either vehicle live and just waiting to kill your rescuer on any body who comes in contact with the circuit. In an accident anything could become live.
I would think it might not only be foolish but maybe illegal.

A similar problem occurs with gas. In an accident pipes can become torn apart, valves smashed, the potential list of problems goes on and on.

A mate told me his brother in law is a cop and whenever he stops a caravan or camper trailer/ van or a motor home the first thing he checks is the gas bottle.
If it is on he writes them out a ticket.
Third hand advise I know but well worth heeding.

Hope this helps, Bruce.

Hi, fridges suck a lot of power as mentioned. While driving with the fridge on 12V DC- 90 litre Dometic - the car voltmeter reads 14.3/14.4 volts as it tries to maintain voltage in both the car and van batteries. If I remember to, I switch the fridge off for the last 30 mins of the journey to let the van battery voltage build up again so the laptop won't cause the inverter to bip later in the night. If I have to I can idle the car for 10 mins. It's a juggling act but part of the camping experience..... W

Never use anything via an inverter when mobile - if you have an accident there is a risk of electrocution. In the past rescuers have been zapped but thankfully not fatally.

Bula All respondents

Never had the intention of running Fridge on Gas when driving.

Good point with running fridge on 240vac inverter when driving, safety first!!!

Thanks for the reply's, some good points, some peoples replies are taken as an insult to ones intelligence.

Will be running fridge on 12vdc when traveling and gas when parked up for the night.

Moce

Bonji