Frigoboat freezer

[Typhoon]

Originally Posted by masonc

I got time to look carefully at the installation on our boat, the thermostat sensor is attached physically to the evaporator. All good.
Has anyone cured the keel cooler oil slugging issue without replacing the keel cooler? I'm thinking to make up adaptors, disconnect the keel cooler and blow a lot of air through it for some time to flush the oil. It would be much more effective if the cooler was inverted but that is not possible until we haul in hurricane season. I need to fix this now.

Once your compressor gets going , does the system function normally, cycling on and off properly and frosting the plate ? Or does it struggle to start every time it cycles off?

Regards John

[Richard Kollmann]

Masonc, the next thing you will be told are you should find and install a box stretcher to improve your refrigeration units performance. Changing thermostat temperature sensing unit and Keel Cooler oil blockage are foolish shotgun approach ideas when you have a three flash LED trouble code.

[masonc]

Originally Posted by Richard Kollmann

Masonc, the next thing you will be told are you should find and install a box stretcher to improve your refrigeration units performance. Changing thermostat temperature sensing unit and Keel Cooler oil blockage are foolish shotgun approach ideas when you have a three flash LED trouble code.

I don't understand what you are recommending i do.

[masonc]

Originally Posted by ColdEh Marine

Once your compressor gets going , does the system function normally, cycling on and off properly and frosting the plate ? Or does it struggle to start every time it cycles off?

Regards John

It runs fine for days

[Typhoon]

Originally Posted by masonc

It runs fine for days

Sounds like you are experiencing an intermittent captube blockage. Depending on how old your system is and how many hours are on it. This may be caused by oil sludge/varnish build up inside the captube. Next time this occurs , try defrosting the system and then warm up the captube with a hairdryer or a hot rag . If this is the problem it may clear it for the time being and get you running , but it will surely show up again. The only real cure is to replace the captube.

It may help and it is non destructive

Regards .

[masonc]

I have a spare evaporator plate, let me see if the connectors are compatible. I don't think they are, the installed system is reusable and the new one is one time.

[Typhoon]

Originally Posted by masonc

I have a spare evaporator plate, let me see if the connectors are compatible. I don't think they are, the installed system is reusable and the new one is one time.

If it has a captube, perfect. Solder it in , replace the filter drier, and oil while you are at , (make sure you put the filter drier on the liquid line some frigoboats had them on the suction line) . Evacuate the system , if you have access to nitrogen then you could purge it a couple of times helps to get the moisture out .

Regards John.

[Richard Kollmann]

What do you recommend I Do?

First you pin down the problem area using common sense by nondestructive means. Destructive experimenting with refrigerant circuit is one way to get in trouble.

As I understand your refrigeration unit cools some of the time. It does not get as cold as it should. And sometimes compressor fails to start running displaying a trouble flash code of three flashes every four seconds. Without jumping to any silly conclusion I would begin with a process of elimination:
1. Confirm that the LED three flash code is the fist code when power is turned. The memory chip in this unit will allow first code to be covered up and a three flash overload code will occur as compressor tries to restart.
2. A three flash code is common on these variable speed compressors when there is a week spot in boat’s grounding system. To eliminate possible trouble with module ground run a jumper direct from Danfoss module direct to battery ground post.
3. Troubleshooting each system design is different so history and brand is important Frigoboat keel cooler systems are more difficult to evaluate refrigerant flow troubles than other type units. As a rule a BD compressor with cap tube refrigerant flow control blocked and correct amount of refrigerant will prevent an overload amperage from stop compressor. So with a three flash code knowing history of anyone tampering with refrigerant could first lead you to believe system may need to be super dehydrated.
4. Thermostat control needs to be eliminated as a cause of poor temperature control. The best way to eliminate any electrical control over compressor starting and stopping is to disconnect speed and thermostat wires from Danfoss control module terminals C and T. By placing a jumper wire across C and T module terminals compressor will now run at minimum speed continuously until power is turned off. After running 8 to 24 hours box temperature should be very cold and frost covering 90% of evaporator surface. If plate frosts over then frost goes away leaving only cold condensation at 33 degrees F no matter how long compressor runs there is moisture contaminates freezing and thawing in refrigerant.
5. Frigoboat keel cooler systems have got a lot of attention because of Capillary tube restriction but jumping to the conclusion the cap tube blockage is generally a mistake.
An experienced refrigeration tech can tell if refrigerant volume is normal by refrigerant flow hissing sounds in evaporator and where frost is present. Refrigerant line temperatures and amperage of system operating will take a lot of the guess work out good or bad performance.

[masonc]

Originally Posted by Richard Kollmann

What do you recommend I Do?

First you pin down the problem area using common sense by nondestructive means. Destructive experimenting with refrigerant circuit is one way to get in trouble.

All excellent suggestions, thank you for taking the time to list them. As soon as I get some time I'm going to walk through these tests and I will report back.
I have a new air cooled compressor system, thermostat and an evaporator that has never been installed, I need to test that first to check it is working. If after I test the installed system the situation is not resolved I think I will convert to air cooled.

[masonc]

I checked the flashes today. Starting from ambient temperature, I had someone turn on the breaker that supplies the compressor. There was a slight flash as the system powered up. Then a couple of seconds later, three flashes.
What does that tell you?

[a64pilot]

Overload, meaning that the compressor drew too many amps.
The first flash is normal power up, then compressor tried to start, drew too many amps, the controller shut it down and threw the trouble code

http://www.kollmann-marine.com/tip2.aspx

[Richard Kollmann]

I can not know why you are seeing the quick flash but a low voltage spike can not be ruled out.
Without this quick flash I would go first to the step that rules out a poor ground by bypassing boats ground wiring known to cause three phasing coil problems inside compressor.

Next step is to eliminate all the possible connection in boat’s wiring to again eliminate a voltage spike during the module boot up sequence. This is accomplished by using proper sized jumper wires direct from fully charged battery terminals direct to module plus and ground terminals. The plus jumper must have a 15 fuse.

If you have not removed the speed and thermostat control wires from Danfoss module terminals C and T do it now eliminating these systems by placing only a jumper wire between C an T module terminals. If compressor does not run now try another electronic control module or have your module tested on another unit.

If you have eliminated all non destructive possible tests what is left is a possible compressor overload causing compressor to exceed 10 amps during boot up starting sequence. One of the design weakness of a keel cooler’s very small condenser and capillary tube refrigerant flow control is there is no space for high pressure liquid to be stored . Too much refrigerant or normal refrigerant flow restricted will causes high amperage at module triggering the safety circuit to stop compressor.

These Frigoboat keel cooler have had a history of refrigerant flow restrictions other systems seem to never experience. The question is after eliminating the normal causes of a high amperage overload and electrical problems how to rule out refrigerant pressure and restricted flow trouble. Sometimes an ammeter or pressure gauges can detect refrigerant problems but first compressor must run.

If everything else was ruled out and because this is a Frigoboat keel cooler unit I would start a slow removal of refrigerant. With system at rest for at least 5 minutes remove refrigerant out of suction side for 5 seconds and try to start up system again. Repeat this process until there is no pressure in low side of unit. If you are lucky there may be a High pressure service connection on your unit near the mechanical refrigerant line connector with a refrigerant gauge connected here. It refrigerant pressure in high side of system can be reduced to 40 psi or less, compressor should run as all other electrical trouble causes have been eliminated.

What action comes next I will wait tell you respond to the above,