Old AB Coldmachine - Variable speed

[FredVeroMakani]

Hi,
I have a AB Coldmachine that is now 30 years old and running fine. The system was installed on a boat supposed to Cruise in Europe and we are now in the tropics. the system is running fine but it pulls 6amps and about 83AH /day. I was wondering if these controllers could change the compressor rpm with adjusting the resistance of the thermostat wiring? (like for newer controllers)

Thanks

[a64pilot]

I would say certainly they can, but maybe you have an older controller that can’t, but the newer ones it’s as simple as changing the resistor in line with the thermostat to get the desired RPM. The data is available on line from Danfoss, both speed and amp draw
That is a lot of draw for what I think is a small compressor though, more than I thought it is capable of.
Others will be here shortly I’m sure

I’m going to assume they will want a picture of the controller.

[Coolerking]

There is an inline resistor you can buy.
See this link for the values and more info.

http://files.danfoss.com/TechnicalIn..._pk100c802.pdf

[Richard Kollmann]

Originally Posted by FredVeroMakani

Hi,
I have a AB Coldmachine that is now 30 years old and running fine. The system was installed on a boat supposed to Cruise in Europe and we are now in the tropics. the system is running fine but it pulls 6amps and about 83AH /day. I was wondering if these controllers could change the compressor rpm with adjusting the resistance of the thermostat wiring? (like for newer controllers)

Thanks

If Danfoss electronic control module is attached to compressor with one screw it is a fixed speed compressor running at 2500 Rpm and its speed can not be increased or decreased.

There are two ways to improve the amperage energy performance COP on your 30 year old unit lower the amperage to five amps by first improving condenser air cooling, and if that does not work slowly and I mean slowly remove less than one ounce of refrigerant until amp draw is stable at 5 amps.