Dometic fridge issue

[1st ade]

1 minute ago, Alan de Enfield said:

 

 

NO problem - except - that when his posts are finally listed it makes the thread very distorted as we 'appear' to have been asking certain questions which he has already answered, as his 'delayed' post goes into the thread at the time he posted it, not the time the mods released it.

Totally understand...

[Tony Brooks]

3 hours ago, matthewbalzan said:

Sorry, solar are connected to battery. All equipment is connected to fusebox 

 

Problem increased, after 3 hrs use the fridge surpassed 8.5amps and could feel the wire quite hot! Definitely not leaving it on overnight

 

 

 

If the wire is getting hot then it is definitely undersized for the current being conducted BUT that may be caused by a fridge fault rather than a cable fault. As I said, the recommended cable size is to do with starting surge, not running consumption. I am starting to suspect some kind of fridge fault. The thing is trying to draw as much currant as an old 3 way fridge running on 12V. Could you "jury-rig" a couple of hefty cables between battery and fridge to see if it improves things? If it does, then it will be a cable issue.

 

Have you taken on board that the cable sq mm size is the CONDUCTOR cross-sectional area, not the cable diameter or anything related to that?

Edited July 30, 2023 by Tony Brooks

[Alan de Enfield]

3 hours ago, matthewbalzan said:

Problem increased, after 3 hrs use the fridge surpassed 8.5amps and could feel the wire quite hot! Definitely not leaving it on overnight

 

 

This gets more unreal as time goes by.

 

A 4mm2 cable is rated at 40 amps - no way is 8 amps (20% capacity) going to make the cable 'quite hot'. I doubt it would even be 'warm'.

 

Are you 100% sure that the cable is 4mm2 and not 4mm diameter ?

 

I asked this several hours ago and suggested ways you could tell if it was 4mm2. Are you able to do these checks ?

Edited July 30, 2023 by Alan de Enfield

[Ronaldo47]

22 hours ago, matthewbalzan said:

I am having some doubts now that the fridge needs some maintenance but it does cool down from around 35 degrees to set temperature of 9 degrees in hot Mediterranean weather in about 2 hours which I think is fairly good.

Could the problem be to do the "Mediterranean weather"?  Some years ago I remember reading an article that advised people who were intending to move aboad to warmer climates that there was no real point in taking their fridge with them as the insulation of UK-spec fridges was inadequate for hot climates, and a fridge in a relatively poorly insulated boat is going to be subjected to higher temperatures than one in the kitchen of a house. I well remember that our first fridge, an Electrolux gas fridge bought around 1960, had much thicker walls than our later models, likewise with the fridge in my late brother-in-law's house in France.

Edited July 30, 2023 by Ronaldo47

[matthewbalzan]

No I am not sure about type of wires, I have no knowledge in electrical components. Will get an electrician to try and sort it out

[Tony Brooks]

28 minutes ago, matthewbalzan said:

No I am not sure about type of wires, I have no knowledge in electrical components. Will get an electrician to try and sort it out

 

If you have some of the same size or spare length then strip it back half an inch and count the copper strands, as Alan advised earlier. It is all but certain each will be 0.30mm in diameter, so if you tell us how many strands, we can tell you the conductor cross-sectional area. We might be able to get an idea if you tell us the overall diameter, including insulation, but that is not so accurate because there have been/are two types of insulation and one is thicker than the other.

 

For instance standard PVC with an OD of 4.2mm has a conductor CCSA of 3 sq mm, while thin wall with and OD of 3.7mm has a CCSA of 4 sq mm

Edited July 30, 2023 by Tony Brooks

[MtB]

25 minutes ago, matthewbalzan said:

No I am not sure about type of wires, I have no knowledge in electrical components. Will get an electrician to try and sort it out

 

 

The size is usually written on the wire! 

 

Can be quite feint or hard to spot.

[Alan de Enfield]

8 minutes ago, Tony Brooks said:

It is all but certain each will be 0.30mm in diameter,

 

If it 2.5mm2 it could be 50 strands of 0.25mm wires

If it 2.0mm2 it could be 28 strands of 0.30mm wires

If it 1.5mm2 it could be 30 strands of 0.25mm wires

If it 2.5mm2 it could be 50 strands of 0.25mm wires

If it 1.0mm2 it could be 32 strands of 0.20mm wires

If it 1.0mm2 it could be 14 strands of 0.30mm wires

[Tony Brooks]

2 minutes ago, Alan de Enfield said:

 

If it 2.5mm2 it could be 50 strands of 0.25mm wires

If it 2.0mm2 it could be 28 strands of 0.30mm wires

If it 1.5mm2 it could be 30 strands of 0.25mm wires

If it 2.5mm2 it could be 50 strands of 0.25mm wires

If it 1.0mm2 it could be 32 strands of 0.20mm wires

If it 1.0mm2 it could be 14 strands of 0.30mm wires

 

Yes, that is for the smaller cables to comply with the ISOs demands for a minimum number of stands. In this case, if the OP is correct about around 4mm it is likely to be strands of 0.30mm

[Alan de Enfield]

1 minute ago, Tony Brooks said:

 

Yes, that is for the smaller cables to comply with the ISOs demands for a minimum number of stands. In this case, if the OP is correct about around 4mm it is likely to be strands of 0.30mm

I agree, but I'm seriously doubting that it is 4mm2, hence if he counts then and finds (say) 30 and each is 0.25mm he knows what size he has