[ncapener]

Maybe not insane, but I have to drink warm beer on occasion

Nova Kool LT 200
Year 1988
R-12

When I turn the unit on, it runs (and cools) anywhere from 5 minutes to several days. When it works right, it cycles properly keeping a constant temperature.
I checked all the wires, checked the voltage.
Shutdowns have occurred with fully charged batteries and low batteries, plugged into shore power, cool days in winter, warm spring days, other appliances running or not, beer in the fridge or not.

When it stops running, every three or four seconds there is a one second high pitched squeal. The unit will not restart by itself.
At this point, I turn power off and then back on. Sometimes it starts right away, sometimes it takes a long time flipping the breaker off and on.

Any ideas?

Thanks,
Neal

 

[Zanshin]

Sounds like the compressor might be trying to start - unsuccessfully. Do you see a big spike in the amps drawn when you hear the noise?

 

[ncapener]

Sounds like the compressor might be trying to start - unsuccessfully. Do you see a big spike in the amps drawn when you hear the noise?

No spike in Amps.
I suspect, the motor is AC. I know a DC motor draws large Amps when stalled, don't know about a AC motor.

Neal

 

[celenoglu]

ıf the unit functios randomly, check the termostat.

 

[ncapener]

Replaced thermostat, also jumped the thermostat to see if that makes a difference. It did not.
Neal

 

[JimsCAL]

Sounds like the compressor might be trying to start - unsuccessfully. Do you see a big spike in the amps drawn when you hear the noise?

I would also vote for the compressor or the fan if the condenser is air cooled. It definitely sounds like something motor driven.

 

[ncapener]

I would also vote for the compressor or the fan if the condenser is air cooled. It definitely sounds like something motor driven.

Compressor has a fan that works fine. I did disconnect the fan for a while and that made no difference in the behavior.

I checked the motor per troubleshooting instructions and it checks out. Procedure is checking for resistance. I am wondering what could be wrong with the motor? I am assuming it is an AC motor (no brushes to wear out) so a short, a burnt out winding, corroded wires and whatever would be there and not intermittent.
What makes troubleshooting so difficult that I cannot induce the failure and there seems to be no "outside" element that makes the unit stop.

The only "clue" I have is that after a stop the unit will not restart at all by itself. It can sit there for days squealing, but if I turn the switch off and on it might start right away.

Neal

 

[ardoin]

Check the sea strainer, flush out with a hose if needed. If it is air cooled pull the cover off the compressor and check the fins for dust.
Some units give a "low preasure" shutdown if the cooling unit is not performing properly. Dirty heat exchange can cause problems and put a real strain on the motor.

 

[Capnblu]

I think your refrigerant needs recharging. Maybe the compressor relay is malfunctioning. Those are my two guesses, for my 2 cents.

 

[JiffyLube]

If the unit has a controller, that is more than likely the problem. I had a situation like yours sounds with my AB, and a new controller solved the problem.

You might want to read this forum KollmannMarine Boat Refrigeration Specialist

 

[deniseO30]

Most hermetic compressors have an internal high pressure bypass as well as over current/heat protection. I don't know about yours but it could be going off on "high head pressure" which is caused by low flow of air (or water) across the condenser. Also those little fan motors have a notorious way of making the squeaking noise until the bearings warm up, then they innocently just spin as quiet as always.