3 Way Fridge 12 volt issues

[altnapaste]

Out using the camper recently and while driving the 12volt system was on and chilling the fridge. when we noticed the 12volt
meter for leisure batteries was indicating a massive drain on the batteries. This was isolated to the 3 way Fridge.

System is Merc Sprinter 2014 , Sterling 60 Amp Battery 2 Battery charger, and 3 No 75 Amp Batteries connected via Copper Bus Bars

All the wiring seems fine now ive checked it but something within the Fridge is draining the system massively and if left on will trip the B 2 B charger overload.
Fridge works perfectly on gas and 240 volt .

Any ideas please.

Rob

 

[Paullus1959]

Hi Rob.
Is the vehicle new to you or is it a situation that has not occurred previously?
The reason for my question is that I'm referring to the Thetford three-way fridge in my caravan. When being towed the fridge receives a 12 volt supply from the car which is backed up by the alternator. This is sufficient to keep the fridge cool. However, the fridge isn't designed or intended for to run on 12 volts independent of the vehicle charging system, it has to run on gas or 220v for it to work.
A fridge running solely on battery power will flatten the battery very quickly without an alternative backup charging system i.e. the alternator, a solar panel array or a generator.

 

[altnapaste]

No the system was designed to run only when engine is running (travelling) the supply is superb from the B 2 B charger which can if required deliver up to 60 Amps never seen that much ever mind ha . Normally the 12volt is stable between 12.4 and 13.2 ish as the B2B switches in and out . Now the discharge rate can be seen on the volt meter and graph as you drive. Just I am not sure if the 12 volt part of the 3 way has its own element and how it functions.
This is a new symptom after 4 years of faultless operation.

 

[ProfJohnL]

Three way fridges will have separate 12Vdc, 230Vac elements.

 

[Dustydog]

Maybe this should be moved to the motor home section.? A wider audience perhaps