Dometic fridge issue...

[benk]

Wondering if anyone has had this issue and if they can help pinpoint where the fault is.

I have a self build camper with a Dometic CRX50 fridge. It's powered by a leisure battery which charges via split relay as well as a 200W solar.

Initially after fitting the fridge I found that it would sometimes have the warning light to display that it wasn't receiving enough power. I fitted the solar (which was my plan anyway) and this fault stopped.

More recently my solar panel failed and I was only alerted to this when the fridge started cutting out again. I've had the panel replaced and it's working fine now, the fridge however continues to be temperamental, (I'm now living in the van full time) sometimes displaying the warning light that it's not getting enough juice. I first thought this was just at night or not in direct sunlight however its now done it a few times when I can see the solar is up and running fine. For example yesterday I was testing the fridge, the panel was working and in direct sunlight. The fridge worked but I was turning it on and off a few times to make sure the switch didn't have a loose connection and all of a sudden it started displaying the low power fault. I waited a few minutes, tried it again and low and behold it worked.

I've checked the leisure batter and it is good (12.65v I think) and been advised that it should have enough power in it to power the fridge without the solar.

Unfortunately I can't easily get to the back of the fridge to check what voltage it's getting but I'm fairly sure I used decent wiring to avoid loss of voltage however to me either loss of voltage or a fault with the fridge seem like the most likely option?

Anyone else had a similar issue or have any advice?

thanks

Ben

 

[boggie]

Check on your settings, on mine there are 3 levels for the voltage level warning, turned it to a lower level fixed it.

 

[Robmac]

What size/type is your leisure battery, and how often are you running the engine?

 

[trevskoda]

One small 100amp battery will run a smal tripple a fridge for almost 24 hrs, however i have 180ah set of battery bank and 200w solar and have never had a problem.

 

[Robmac]

One small 100amp battery will run a smal tripple a fridge for almost 24 hrs, however i have 180ah set of battery bank and 200w solar and have never had a problem.

I wondered if he had Lithium Trev which will withstand a much deeper DOD.

 

[AndyC]

Sounds like a typical low voltage problem. I would be checking the voltage at the fridge when it's running and then work back along the wiring.

 

[merl]

This is a common issue with Compressor fridges, people look at the consumption figures and choose a cable size accordingly but that doesn't allow for the much higher current drawn momentarily when starting up. Sounds like yours is right on the cusp of being adequate. Increase the cable guage, you may get away with doing just the pos or neg only if you do just one and retry it but bear in mind things get worse as the battery voltage gets lower so probably best to build in a safety margin and do both.

 

[Fazerloz]

Mine was power hungry so replaced the cables for larger ones but whilst I had the fridge out I noticed a unused earth spade under the comp that is not mentioned in the installation manual so I added another earth from the spade to the van body and it greatly reduced the power consumption.

 

[Fazerloz]

You could also add a switch to easily turn off the power to the fridge through the night as nobody will be opening the door, There is little temp change in the fridge overnight.

 

[Robmac]

This is a common issue with Compressor fridges, people look at the consumption figures and choose a cable size accordingly but that doesn't allow for the much higher current drawn momentarily when starting up. Sounds like yours is right on the cusp of being adequate. Increase the cable guage, you may get away with doing just the pos or neg only if you do just one and retry it but bear in mind things get worse as the battery voltage gets lower so probably best to build in a safety margin and do both.

I think I used 6mm2 for mine Merl, does that sound about right?

Anyhoo, I've never had a problem with it on leads or Lithium.

 

[merl]

Mine was power hungry so replaced the cables for larger ones but whilst I had the fridge out I noticed a unused earth spade under the comp that is not mentioned in the installation manual so I added another earth from the spade to the van body and it greatly reduced the power consumption.

It would be interesting to know exactly what's going on there and how adding an additional ground/neg/ could reduce overall consumption?? Odd

 

[merl]

I think I used 6mm2 for mine Merl, does that sound about right?

Anyhoo, I've never had a problem with it on leads or Lithium.

I think 6mm is typically fine but It'll depend on fridge type/size and cable length but proof of the pudding and all that, if it's working ok then it's...OK!

 

[Robmac]

I think 6mm is typically fine but It'll depend on fridge type/size and cable length but proof of the pudding and all that, if it's working ok then it's...OK!

Yeah sorry, I meant that as a suggestion for a cable replacement for the OP.

Mine has a cable length up one side of the van, across the roof and down t'other side so about 12 feet.

 

[benk]

You could also add a switch to easily turn off the power to the fridge through the night as nobody will be opening the door, There is little temp change in the fridge overnight.

Yes I have this already thanks

 

[benk]

What size/type is your leisure battery, and how often are you running the engine?

Thanks. It's lead acid 12V 110AH Expedition Plus Semi Traction Leisure Battery, using the engine every day at the moment

 

[Robmac]

Thanks. It's lead acid 12V 110AH Expedition Plus Semi Traction Leisure Battery, using the engine every day at the moment

I used to get 3-4 days out of my 240AH Trojans running the fridge (occasionally switching it off overnight) and used the lights and a bit of TV. Since I've switched to Lithiums though and large amounts of solar on the roof I don't even have to think about it anymore - wish I'd done it years ago but then it would have cost a lot more!

Sounds like you have a voltage problem though so you are in good hands with those who know a lot more than I do who are responding. Best of luck with it.

 

[Fazerloz]

It would be interesting to know exactly what's going on there and how adding an additional ground/neg/ could reduce overall consumption?? Odd

I thought the same, But it did. At the time a good few years back I think I did a thread about it showing the different meter readings. At the time I know i was pushed for time to get it back in because we were going away and thought "that'l do" and I've never looked for a reason, But why put an earth point on for no reason. I remember it making a considerable difference.

 

[merl]

But why put an earth point on for no reason.

You'd typically find a random earth spade where something needed grounding in order to comply with interference suppression rules.

 

[Drover]

Check on your settings, on mine there are 3 levels for the voltage level warning, turned it to a lower level fixed it.

I did exactly the same with mine.

 

[bartman]

I have a state of charge meter where all -ve connections have to go via a shunt. Does that restrict the amount of current that can be supplied?