Compressor Problem

[gbendaly]

good day to all

my fridge compressor is a danfoss 35 BD.. whenever I am on shore power charging my batteries via the sterling 3-stage charger.. it works just fine
and the evaporator plate is covered with ice
when I sail, the battery bank is charged via a solar panel and the engine alternator (when needed) but the compressor fail to work CONTINUOUSLY
it starts and shut off at intervals failing to keep a proper temperature inside the fridge.
the voltmeter hooked to the batteries seldom drops below 14.5 Volts
I wonder if any one has an idea of what is happening and can advise me how to keep the compressor working
thanks
georges

[GordMay]

Danfoss puts out numerous helpful Technical documents, supporting their compressors & control modules.

➥ Refrigeration & Air Conditioning - Documentation - Danfoss

➥ http://www.ra.danfoss.com/TechnicalI..._pa100a202.pdf

[Talbot]

I would be looking at the voltage at the compressor, then investigating the wiring back to the batteries. Sounds like there may be a poor joint somewhere, or the wire itself is sub standard or inadequate to get the ampage to the compressor.

[Pelagic]

Another possible reason, if the wiring is ok, is that your compressor is at the upper limit of operation due to dirt or age.

At the marina, when things are calm and your charger DC power is at its best, it still works.

But underway, with motion and variable DC, resistance builds up and it cycles off.

Clean it/ test it with batteries only at the dock and measure the amount of amps it draws when it cycles on, so as to confirm with Danfoss specs if resistance is too high

Also, how old are your batteries?

[gbendaly]

Originally Posted by Talbot

I would be looking at the voltage at the compressor, then investigating the wiring back to the batteries. Sounds like there may be a poor joint somewhere, or the wire itself is sub standard or inadequate to get the ampage to the compressor.

thanks
will do

[gbendaly]

Originally Posted by Pelagic

Another possible reason, if the wiring is ok, is that your compressor is at the upper limit of operation due to dirt or age.

At the marina, when things are calm and your charger DC power is at its best, it still works.

But underway, with motion and variable DC, resistance builds up and it cycles off.

Clean it/ test it with batteries only at the dock and measure the amount of amps it draws when it cycles on, so as to confirm with Danfoss specs if resistance is too high

Also, how old are your batteries?

the compressor is more than 5 years old ( according to the first owner)
and yes it is dirty .. how do I clean it any suggestions ?..
the batteries are 6 months old
I will as suggested measure the amps it draws when working and compare with danfoss specs..
thanks for the input

[gbendaly]

someone at the marina suggested I connect the compressor directly to the batteries and install a dedicated switch without passing through the panel board .. is this ok?? ..

[Sunspot Baby]

Is your fridge 110/12 volt? If so there is a converter in the circuit that puts out 24 volts while the 110 is on (like when your on shore power). When not on shore power the 12v from the battery is supposed to go straight through. Many Danforth compressors are dual voltage 12 or 24.

I had a problem with 2 different converters working fine on 110 but something goes wrong on 12v. The voltage is there, but not sufficient amperage. When I take the converter out of the circuit and just run 12v everything works fine.

I suspect from your symptoms, you may have the same problem. Check to see if there is a converter in the circuit.

George

[s/v Jedi]

If your batteries are almost never under 14.5V you have a problem. They should be kept at 13-2 - 13.8V (depending on make) and only get to that higher 14.5V level for a limited period during charging. Maybe the shutdowns are a high-voltage safety feature.

cheers,
Nick.

[Pelagic]

Originally Posted by gbendaly

the compressor is more than 5 years old ( according to the first owner)
and yes it is dirty .. how do I clean it any suggestions ?..
the batteries are 6 months old
I will as suggested measure the amps it draws when working and compare with danfoss specs..
thanks for the input

If you can pull it out then blow it down with compressed air and clean any filter materials same way

[Sunspot Baby]

If you pull it out be careful not to lose the coolant charge.

George