Fridge Problem (maybe.)

[Retardedrocker]

Greetings all.

I have an electrickery issue which has baffled me (easy) and the guys at the marina (not so easy.)

The fridge packed in: lights on but compressor not running. I've checked the batteries and they seem to be ok. They're about 2 1/2 years old and the voltage on float is 13.7v. The voltage at the fridge is the same give or take 0.1v.

If I turn the inverter/charger off and then on again the batteries show a voltage of 14.9 and the charger runs on absorption (for 10 - 15 minutes) and the fridge starts running.

The Eberspacher and everything else works fine, but the 12v lights are sometimes a bit dim.

We have tried a new fridge and that was the same.

I would appreciate any suggestions.

Cheers,

T.

[Robbo]

9 minutes ago, Retardedrocker said:

Greetings all.

I have an electrickery issue which has baffled me (easy) and the guys at the marina (not so easy.)

The fridge packed in: lights on but compressor not running. I've checked the batteries and they seem to be ok. They're about 2 1/2 years old and the voltage on float is 13.7v. The voltage at the fridge is the same give or take 0.1v.

If I turn the inverter/charger off and then on again the batteries show a voltage of 14.9 and the charger runs on absorption (for 10 - 15 minutes) and the fridge starts running.

The Eberspacher and everything else works fine, but the 12v lights are sometimes a bit dim.

We have tried a new fridge and that was the same.

I would appreciate any suggestions.

Cheers,

T.

Try cleaning up all the connections between fridge and batteries.

[dor]

Sounds like a bad connection.  The voltage at the fridge might be the same because of a high resistance on the return.  Voltage drop is related to current and if the current is very low, there will be next to no voltage drop.

 

[Retardedrocker]

Thanks to you both.

The wiring is pretty inaccessible, but I'll give it a shot. One thing 

I didn't mention is that when the fridge door is opened the voltage drops to just over 12v. The Shoreline won't run at less than 10v

[john6767]

I would also say bad connection, I had similar in that the fridge was having problems when the engine was not running.  It was the connections in the isolator switch by the fridge that connects the boat wiring to the fridges flexible cable.  Even though the wiring may be inaccessible, it should hopefully be a single cable run so you are really only looking at the two ends.

[Bee]

Wiring is funny stuff but in this case I think I would get a couple of lengths of decent cable and just go straight from the batt to the fridge and see what happens, if it works ok then the batt is ok and so is the fridge. My guess is connections.

[Tony Brooks]

1 hour ago, Bee said:

Wiring is funny stuff but in this case I think I would get a couple of lengths of decent cable and just go straight from the batt to the fridge and see what happens, if it works ok then the batt is ok and so is the fridge. My guess is connections.

Remember both to be 1 sq mm CCSA for each metre between battery & fridge.

Sounds like a voltdrop problem to me so if it used to be fine its probably a bad connection. Check the negative bus bar for loose screws.

[Retardedrocker]

Thanks for all the replies and (pretty unanimous) advice.

I'll check it out and report back.

Cheers,

T.

[Nickhlx]

What are the battery volts, after being on float, but when there is a load attached ? ( i.e. fully charged but supplying a load of say 25 amps....)  Although  only 2.5 years old, improper care over that time could (will) have caused damage. 

Whilst the float voltage is normal, as well as the voltage seen when on absorption charge, and the voltage at the fridge is as expected, you don't say whether any current is actually flowing into the fridge..  i.e. it could be a poor connection, but until you know the batteries are OK when under a moderate load, the rest is not going to tell you much.

Nick

[Retardedrocker]

Reporting back as promised.

Yes, the combined wisdom of the forum was, as usual, spot on. The voltage was fine until there was a load, when it plummeted (at least at the fridge) to about 9.5 volts.

The culprit was a bad earth connection, which was well hidden away. It's now a good earth connection and everything is working better than ever.

Thanks for the input. You guys really are life savers, or money savers, which is even more important. 

 

Cheers,

T.

[MtB]

Point of order...

Your 12v fridge doesn't have or need an earth connection. I suggest you mean the -ve connection.  

[Retardedrocker]

Hi Mike.

Indeed I do.

T.