Fridge issues

[Whiterose]

My Fridge on boat Coolmatic..at certain stages seems to be struggling to get compressor going..it “Clicks” but doesn’t start this goes on and on quite often mainly in night.If I open door of fridge compressor starts.Thought this May because of low ambient temperature but doubt it ( does get cold but in Southern Spain). Tried to get suggestions from various places..the boat is 12V but runs on mains through inverter plugged in to shore power.Forumites any ideas?Cheers

 

[Daverw]

Sounds like your thermostat, opening the door would make this open more, the contacts can get lazy. Is the thermostat mechanical or digital?

 

[coopec]

The first thing I'd look at is the cables for power supply to the compressor motor.

How many watts does it take to run a 12 volt refrigerator?
12-volt refrigerators generally range from 40 to 100 watts, although there are both smaller and larger units. A 12-volt refrigerator that features 60 running watts draws on ~5 Amps from the 12V battery.

The cables therefore would need to be quite hefty to carry 25(?) Amps from the battery to the motor on start up. Can you put some jumper leads on to test the hypothesis?


Maybe these links could help?

Waeco Fridge Compressor [Issues And Solutions]

12V Waeco fridge wont start up?

 

[Whiterose]

Sounds like your thermostat, opening the door would make this open more, the contacts can get lazy. Is the thermostat mechanical or digital?

Sounds like your thermostat, opening the door would make this open more, the contacts can get lazy. Is the thermostat mechanical or digital?

it’s mechanical

 

[Whiterose]

Thanks folks will check out your suggestions next week end

 

[Daverw]

If it’s mechanical test by linking it out across terminals and see if it stays running, the thermostat could be Ranco or Danfoss and service kits are available if so.

 

[Ningaloo]

If it were not for the change in behaviour with the door open I'd suggest voltage drop in the cables. Check the voltage at the fridge when the compressor starts. It draws a hefty current for several seconds which can cause a significant voltage drop - sufficient to make any battery protection device kick in. Poor design as you get a repeating stop/start cycle which will eventually have a detrimental effect on your battery.

 

[Whiterose]

Thanks all?

 

[Mark26]

I had the same problem. Struggled with it for some time, even took the fridge back to where I brought it complaining it was faulty.

They tested it in front of me and proved it was working properly. They told me it was a common problem on boats and is caused by voltage drop in the cables.

I was advised to wire it direct to the battery - indeed, it did say this in the instruction book, and not to go through any switches.

As a test a brought a few meters of appropriately sized cable and temporarily connected the fridge directly to the battery, with the cables just running across the floor, for test purposes only you understand, and it worked perfectly.

Since then I have tried many ways of wiring it in and the only one which has worked is direct. It is now wired into the boats unswitched supply through a fuse and works perfectly. I use the fridges own control to turn if off during long periods of non use.

 

[Whiterose]

I had the same problem. Struggled with it for some time, even took the fridge back to where I brought it complaining it was faulty.

They tested it in front of me and proved it was working properly. They told me it was a common problem on boats and is caused by voltage drop in the cables.

I was advised to wire it direct to the battery - indeed, it did say this in the instruction book, and not to go through any switches.

As a test a brought a few meters of appropriately sized cable and temporarily connected the fridge directly to the battery, with the cables just running across the floor, for test purposes only you understand, and it worked perfectly.

Since then I have tried many ways of wiring it in and the only one which has worked is direct. It is now wired into the boats unswitched supply through a fuse and works perfectly. I use the fridges own control to turn if off during long periods of non use.

That’s very interesting, at moment I have it wired through a 240v -22 v transformer ..for when on mains and a switch that connects it direct to battery when not on mains.It has worked fine for number of years but I can understand what you are saying off to Med tomorrow so have a good luck and report back.Thanyou