Help please - Fridge working on shore power but not engine

[doug1720]

Hi,
I have a 12v input fridge (Frigoboat 12V Series 2000 Twin) that works fine on shore power but not under engine. I have upgraded the alternator and fitted lithum batteries and solar. So plenty of energy while underway.

Because the fridge works fine on shore power I am assuming that the issue is the system sensing that the engine is on and charging the batteries.

I have had a look at the relays and contactors that are managing the fridge but still cannot work out the problem and wondering if someone could hel me?

I have attached a drawing of the wiring and also a picture of the contactor and relays. Also I have a brown wire that connects to a black wire and not sure were that goes to or from (I have attached a picture for reference).

Any assistance would be fantastic.

Thank you,
Doug

[JoeRobertJr]

Hi, Doug,
Hopefully, someone else will be able to give you more insight.
My 12V fridge is simply connected to the 12V house batteries, so it does not care about shore power versus alternator. I am not sure of the purpose of the power control components you have drawn.

[newhaul]

Originally Posted by doug1720

Hi,
I have a 12v input fridge (Frigoboat 12V Series 2000 Twin) that works fine on shore power but not under engine. I have upgraded the alternator and fitted lithum batteries and solar. So plenty of energy while underway.

Because the fridge works fine on shore power I am assuming that the issue is the system sensing that the engine is on and charging the batteries.

I have had a look at the relays and contactors that are managing the fridge but still cannot work out the problem and wondering if someone could hel me?

I have attached a drawing of the wiring and also a picture of the contactor and relays. Also I have a brown wire that connects to a black wire and not sure were that goes to or from (I have attached a picture for reference).

Any assistance would be fantastic.

Thank you,
Doug

Sounds like it's not getting 12v so trace power leads from fridge to batteries .
Or run it off of the inverter if you have one untill you get the power from batteries to fridge fixed.

[BCG]

Hi Doug,

I don't fully understand your system. But the drawing shows that when 230v power is available the telemechanique contactor closes providing 12v power to Relay 03.397 and then the fridge.

"As drawn" Relay 03.608 should also close and provide 12v power to Relay 03.397 and then the fridge ,.
This relay is shown (assuming the black wire is connected to negative bus) as energised as soon as the fridge is switched on. Which confuses me slighlty.

As drawn it appears relay 03.608 is not energising, it could be faulty or it may not have a negative on the Black wire that has not been traced yet.

I suggest testing voltage accross terminals 1 & 2 of relay 03.608 I would expect 12.3v or higher, this would indicate the relay not activating. If not you may have another protective device connected in the black wire, so it should be traced investigated. Perhaps there is a device in black wire circuit to stop the fridge fully draining the batteries.

Good luck

[stormalong]

Originally Posted by JoeRobertJr

Hi, Doug,
Hopefully, someone else will be able to give you more insight.
My 12V fridge is simply connected to the 12V house batteries, so it does not care about shore power versus alternator. I am not sure of the purpose of the power control components you have drawn.

This is your answer. KISS

Connect your refer directly to the house battery and remove all of the superfluous wiring and relays. When plugged into shore power your battery charger will keep the house battery charged and all of your 12V needs satisfied - no muss, no fuss.

[bgallinger]

From Stormalong and he gets it right:
This is your answer. KISS

Connect your refer directly to the house battery and remove all of the superfluous wiring and relays. When plugged into shore power your battery charger will keep the house battery charged and all of your 12V needs satisfied - no muss, no fuss.