Isotherm Fridge Problem

[Jim Hood]

Hello everyone

I am looking for help identifying the compressor on my rather old Isotherm refrigerator system. I bought and installed it in Gibralter sixteen years ago and it has been performing flawlessly until now. When it recently stopped working I removed the compressor/condensor assembly to have it checked at a local refrigeration shop here in the Rep of Panama. They suspect the controller since it starts the compressor but it soon stops. Apparently the controller stops supplying power. They tried it on a working Danfoss BD50 compressor (they had to swap two of the three supply wires) with the same result. As you can see from the photos the controller is an ASU unit which has the ability to speed up the compressor when it detects an elevated voltage at the battery (when charging for example). However, I normally use the system switched to manual where it cycles at low speed controlled by a thermostat. What I would love to do is find out what kind of compressor the system has and whether a simple controller with a manual thermostat might still be available. The labeling would suggest it's an Isothem!? As it's a three pin 12volt compressor could a Danfoss controller be used? I don't know that much about refrigeration but I hesitate to condemn the system without doing a little research. Thanks for any help you can give.

Jim Hood SV Charmer Panama

[Richard Kollmann]

This compressor looks like a Electrolux now sold by ACC compressors model GD30FDC Technautics used this compressor on their Cool Blue refrigerator. Contact Randy he may be able to help you.

[Jim Hood]

Thanks a lot Richard

I have written to Randy as you suggested. I have also had a look around the net for GD30FDC compressor references. I didn't find anything in connection with Electrolux but it's on a site with a label Cubigel Compressors. It's certainly a current model and there is a controller called a FDC1 for it which looks pretty clever. Couldn't find anyone selling them though so I have no idea how much they are or who to contact. I'll keep looking. Out of interest how interchangable are 12v compressor controllers? They are producing three phase ac are they not?

Thanks again

Jim

[Richard Kollmann]

Jim, I have a Manual I downloaded several years ago in my library, Thy searching on web:

ACC compressor GD30FDC USER MANUAL

This unit’s electronic module has a RJ11 connecter plug for a computer Serial Port Interface Allowing software inside it to be re-programmed from a computer.

[senormechanico]

I have a controller similar to yours I'd sell if you're interested.
PM sent.

Steve

[colemj]

Originally Posted by Richard Kollmann

This compressor looks like a Electrolux now sold by ACC compressors model GD30FDC Technautics used this compressor on their Cool Blue refrigerator. Contact Randy he may be able to help you.

Rich Boren with CruiseRO now owns Technautics: CoolBlue 12v Marine Refrigeration

Mark

[Jim Hood]

Thanks a lot Richard

I have already had a reply from Randy who directed me to the manual you referred to and I now have a copy. Thanks.

[Jim Hood]

Dear All

Thanks for all the input. Just writing to update on progress. I retrieved the compressor and controller from the shop and set about re-assembling it on the boat last week. Borrowed a flare set from a friend and belled out the pipes which the shop cut to make solder joints. I installed a new filter/dryer since the system had been open for a while. I reconnected everything and the compressor sprang into action as if there had never been a problem!? As an aside, the shop could never have gotten the compressor running since the sophisticated controller doesn't start without everything connected and that includes the thermistor. I had left it in the boat as it is tucked behind the holding plate. Anyhow I vacuumed the system and filled it as per the instruction sheet that is available from Isotherm Parts web site. That was three days ago. So far everything is working well. For those interested in the suctions pressures. I filled the system to 19 psi on the suction side with the system running and as the instruction sheet said the pressure dropped as the plate cooled to about 15 psi. It stayed there for over an hour and a half as the plate froze and then proceeded to fall again eventually reaching 7.5 when the thermistor switched the system off. I had the manual temp dial set to around 4 o'clock. With the door remaining closed it then cycled on and off approx 30 mins on then 1hr 45mins off. Although the boat is in the tropics with temperatures regularly in the 80's the rather small ice box (a little over 2 cubic feet) is well insulated average 6" refrigeration foam. The question remains, why did the system shut itself off? Well perhaps the fault will happen again and I have only bought a little time but I wonder if we might have suffered a little lightning strike which upset the board. A little time out of circuit and it re-set itself? Not sure. I have certainly seen several Danfoss controllers wiped out by lightning which is pretty common in this part of Panama.
So there it is, I have learned a lot in the process and would like to thank all who contributed. All the very best

Jim Hood SV Charmer Panama

[colemj]

Originally Posted by Jim Hood

I have certainly seen several Danfoss controllers wiped out by lightning which is pretty common in this part of Panama.

Funny - we took a direct strike that wiped out every single piece of electronics and much of the electrics, but the Danfoss controller was the only thing that survived. And it sits directly next to the mast compression post. The windlass solenoid and inverter/charger next to it smoked.

Mark

[Richard Kollmann]

colemj, I would be interested to know if your refrigerator power and ground wires are connected direct to Battery buss instead of a smaller branch circuit or circuit breaker panel. Danfoss in the past reported the importance of using battery bank as a very large capacitor to protect control module from voltage spikes. Heat and voltage spikes have always been linked to Danfoss electronic module failures.