Freezer doesn't like to go to sea

[Peter Mackay]

Originally Posted by sailorboy1

I certainly would personally look for electrical problem before some physical one. Wouldn't it r eally be easy to find out just by tracking whether the compressor is running more/less underway?

Is it possible that the problem is just in the power supply wiring and batteries? That is why it shows up underway as the compressor it shutting down on low voltage. Happens more in bigger seas because the autopilot runs more.

Yes electrical problems are by far the greatest cause of issues with DC refrigeration, ironically it is usually the boats power supply in and not the refrigeration system itself! But this problem and the OP description makes it highly unlikely to be electrical. For example the unit is not stopping or fault indicating, it loses refrigeration ability and that is typical of the refrigerant flow issue I described.

Cheers Pete

[Peter Mackay]

Originally Posted by Coolerking

I might suggest that the op while at the dock boat level, if possible, un bolt the unit itself and tilt it so it sits like Pete's picture with the spun bullet drier at an angle, then see if his theory is correct?
Seems like an easy way to eliminate possible cause.
We have used literally thousands of these driers in our educational aquarium chillers we sell to schools and fish and game departments worldwide, never had this issue, and they end up tilted at all different angles once they get out in service.
That's not to discount Petes theory at all, just curious to see if you can make this happen at the dock.

I can see your reasoning CK but the issue I described is caused by movement to and fro when small 'gulps' of vapour enter the capillary, and I have only had it occur with freezers. There are millions of freezers that don't have this problem but they are not similarly configured or rockin' and rolling their way around the globe!.
Years ago we did a lot of research looking for reasons for this issue. As stated earlier the causes were varied but all related to 'flash gas in the evaporator supply. Since then we have altered our systems so as to avoid this annoying thing happening.

BTW, good that you don't call those spun copper dryers 'filter dryers' because they are not, they are strainer dryers at best! But that's another issue!

Cheers Pete

[Uncle Bob]

Richard, refrigeration is not my forte which is why I defer to those that are more knowledgeable, I admit that my first instinct would be to check the power supply including the fuse for intermittent faults and if then the problem persists I feel that Peters experience based explanation has merit. I note that his suggestion of moving the end of the drier downwards involves no disassembly, minimal time and should give an indicative result quickly, allowing the OP to have the problem rectified at their convenience later.
I believe that is the benefit of this forum, many hands each with their own experience offering up options towards solving problems with and for others.

[dougweibel]

I am feeling pretty obligated to test out Peter's theory but everyone will have to be patient. Perhaps tomorrow I can take the time to get access to the unit and see what can be tilted with how much effort/risk. Then it is a matter of waiting till we are seeing enough motion to tell if it has made a difference. We are heading down Exuma sound tomorrow, but the forecast is for 5 kt winds so there may not be much motion. After tomorrow we may be hanging around the Georgetown area for a week. Eventually I will get get the theory tested.

Personally I am dubious about an electrical cause for several reasons:

• Five year old boat with high quality wiring
• The problem occurs regarless of sailing or motoring. When motoring the house banks are maintained at full charge voltage.
• I checked the voltage at the unit (at anchor). With a 12.7 house bank voltage I saw 12.5 when the compressor was running and 12.7 when not. 0.2 volts seems like a pretty normal voltage drop for the wiring to the unit and does not hint to me of any weak connection.

But perhaps I am just rooting for Peter's answer as tracking down an intermittent electrical problem is never fun

[Peter Mackay]

Originally Posted by dougweibel

I am feeling pretty obligated to test out Peter's theory but everyone will have to be patient. Perhaps tomorrow I can take the time to get access to the unit and see what can be tilted with how much effort/risk. Then it is a matter of waiting till we are seeing enough motion to tell if it has made a difference. We are heading down Exuma sound tomorrow, but the forecast is for 5 kt winds so there may not be much motion. After tomorrow we may be hanging around the Georgetown area for a week. Eventually I will get get the theory tested.

Personally I am dubious about an electrical cause for several reasons:

• Five year old boat with high quality wiring
• The problem occurs regarless of sailing or motoring. When motoring the house banks are maintained at full charge voltage.
• I checked the voltage at the unit (at anchor). With a 12.7 house bank voltage I saw 12.5 when the compressor was running and 12.7 when not. 0.2 volts seems like a pretty normal voltage drop for the wiring to the unit and does not hint to me of any weak connection.

But perhaps I am just rooting for Peter's answer as tracking down an intermittent electrical problem is never fun

Doug, you might be able to post some pictures here of pipe run from condenser through to the filter etc. This would help in advising you on the best method of tilting the filter although it should be simple and safe to do.
BTW a 0.2 volt drop off / run is excellent, no issues there.

Cheers Pete

[Richard Kollmann]

All pleasure boat ice box conversion refrigeration seem to have weak areas in their designs. Adler Barbour’s CU100 is no exception to design flaw exposure. I have thousands question and answers on refrigeration manufacturers system designs and costumers problem complaints in my many hard drives. The position and location of AB’s filter dryer is not a cause of poor cooling performance. Peter might have something if filter is too large and incorrectly installed on this unit. I would point out again the current repetitive trouble on the CU100 machine is its printed circuit board that can easily be looked at visually to determine if it is in possible failure mode.

Tampering are replacing this small extruded filter/dryer is a risk not worth taking while in the Bahamas based on a dumb theory. If this theory had any merit to this problem there would not be maybe a hundred million of them in use.

[Richard Kollmann]

I will put my money on printed circuit board overloading or boards thermostat phone jack connector's poor connection. The manufacture did not issue a Service Bulletin but I placed a TECH TIP on my web site with typical repairs as replacing board is not a solution until AB re-engineer the board.

[Coolerking]

If you have a laptop, get a temperature data recorder, cheap online.

Put it in the freezer at the dock when unit is working correctly, record for 24 hours.
This is your baseline.

Next time you go sailing, use it again.
You obviously see where im going here...

Have you tried jumping the tstat out at the module? C and T terminals.
on Richards thought, the tstat phone connector is great for a while, until it isn't. I hate them.
I have removed them from the board and wired them direct, the tstat wire is 4 conductor but only the middle 2 are used green and yellow, I just cut the end and put push on red wire terminals.
One other thing i thought of, you say that it only happens underway in a decent seaway, and gets worse with the rise in sea state, how are the gaskets/ hinges? Is it a top load only?
Things to consider, I am a boatbuilder who does refrigeration...and i've seen things....

And for the record, if you think finding intermittent electrical issues is hard, then surely refrigeration repair techniques border on insanity,

[JPA Cate]

Apologies if the thread now reads somewhat disjointedly. A number of posts were either edited or removed, which contained belittling comment, or quoted them.

The thread is now re-opened.

[dougweibel]

With Covid etc. things got very "back burner" but I finally now have some news on this issue. First, I checked the angle of the drier and it was already tilted slightly in the desirable direction. We had a marine HVAC tech take a look and he found the refrigerant level low. While it seemed contrary to all the opinions in the thread we went ahead and let him just add refrigerant to see if that took care of the issue.

We have now been back aboard and living on the boat for 7 weeks and while we have never been in seas of more than 5' we have definitely seen plenty of motion which previously would have caused a problem. However, the unit is working acceptably now. It holds temperature fine under motion. The only time we see it get outside its set point range is when we put unfrozen items into the freezer. For example putting in an ice cube tray full of water that has not been chilled first will make the temperature pop up about three degrees for a few hours.

While I don't feel the freezer has "rock solid" performance I think that the significant change in behavior after just adjusting the refrigerant level rules out the prevailing opinion of an electrical issue.