Frigiboat Running Wild!! Help!!!

[redsky49]

Returned to boat to find ice box colder than setpoint. Compressor continuing to run despite box being 1.3 degrees colder than required.

Tried disconnecting temporarily from power. Upon powering back up symptoms remain.

Raised setpoint 0.6 degrees on Carel thermostat. Compressor continues to run, ice box temperature continues to drop.

Changed smart speed controller from Auto to Manual. Set compressor to slowest speed. Ice box temperature staying roughly constant - 0.8 degrees below setpoint. Compressor continues to run.

System consists of Frigoboat K50F compressor (Danfoss BD50) with keel cooler, Carel programmable T'stat, Compressor speed controller, evaporator coil.

I installed the system in 2005 and, aside from struggling a bit when in really demanding conditions (hot water and air temperatures), it has run reliably.

My guess is that the thermostat has failed, but perhaps there is an issue in the electronic module at the compressor.

Not sure how to proceed. At slow compressor speed box has dropped another 0.2 degrees while typing this. I am afraid I am going to freeze all the contents. What to do?

[Eder]

Try this

(5) General Reset

A General Reset will return all the settings to the factory defaults. Turn power off to thermostat. Then restore power while holding down the “PRG/mute” button.

[Richard Kollmann]

Disconnect the wire from Danfoss Module terminal T or C this will stop compressor if the Carel thermostat is the problem.

[redsky49]

Update:

I noticed that there was a very slight discoloration (as in increased resistance) of the crimped fitting on the primary power connection negative wire to the compressor power/controls module. Both the positive and negative wire felt much hotter than normal (they pick up some heat from the compressor).

I pulled off every single wire I could access and reconnected. Voila! The compressor is cycling as intended, though I am still in Manual mode and will remain there for overnight.

Tomorrow I am going to clean every wire terminal and try to get the Auto mode to function. Perhaps it is just something to be anticipated after ten years service afloat, though I am not yet convinced this is the problem.

FYI, with air temperatures aboard the boat in the mid 80's, outside air low to mid 90's and sea water temps a stagnant 80 degrees plus, my underinsulated refrigerator is running a 70% duty cycle at low speed (3.8A). Overnight the duty cycles drops to around 50% or less which corresponds closely with my tropical average power consumption of 50-60 AH/day for refrigeration. I am going to add some interior insulation and improve the door gasketing this fall in order to reduce power consumption closer to 40-45 AH/day in tropical climes.

Will post results tomorrow. Appreciate the suggestions!

[senormechanico]

Originally Posted by Eder

Try this

(5) General Reset

A General Reset will return all the settings to the factory defaults. Turn power off to thermostat. Then restore power while holding down the “PRG/mute” button.

WARNING !! If the Carel thermost is the same as a Coastal Navigator (I don't know if it is) and you do this, there are a lot of default settings you DO NOT WANT like auto defrost cycle etc.
It's a big PITA to reprogram all those things out.

Richard Kollman has the right answer.
Ask me how I know.

Edit: The Carel is different from the Coastal Navigator, but I hope I have enlightened anyone with a Coastal Navigator.
A general reset will put you in a similar realm of Phone Menu Hell.

[Muckle Flugga]

Originally Posted by redsky49

Update:

I noticed that there was a very slight discoloration (as in increased resistance) of the crimped fitting on the primary power connection negative wire to the compressor power/controls module. Both the positive and negative wire felt much hotter than normal (they pick up some heat from the compressor).

I pulled off every single wire I could access and reconnected. Voila! The compressor is cycling as intended, though I am still in Manual mode and will remain there for overnight.

Tomorrow I am going to clean every wire terminal and try to get the Auto mode to function. Perhaps it is just something to be anticipated after ten years service afloat, though I am not yet convinced this is the problem.

FYI, with air temperatures aboard the boat in the mid 80's, outside air low to mid 90's and sea water temps a stagnant 80 degrees plus, my underinsulated refrigerator is running a 70% duty cycle at low speed (3.8A). Overnight the duty cycles drops to around 50% or less which corresponds closely with my tropical average power consumption of 50-60 AH/day for refrigeration. I am going to add some interior insulation and improve the door gasketing this fall in order to reduce power consumption closer to 40-45 AH/day in tropical climes.

Will post results tomorrow. Appreciate the suggestions!

The Danfoss controller module has an LED fault indicator which you must wire up yourself. Any 12v32v LED soldered to a couple of spade connectors will suffice. Check this out for further details:

LED Trouble Flash Code Tech Tip

[Muckle Flugga]

Originally Posted by Richard Kollmann

Disconnect the wire from Danfoss Module terminal T or C this will stop compressor if the Carel thermostat is the problem.

Didn't see you were already on this. I resign my expertise to yours as already indicated by my previous post! Cheers, S.

[svinvictus2]

Originally Posted by redsky49

Returned to boat to find ice box colder than setpoint. Compressor continuing to run despite box being 1.3 degrees colder than required.

Tried disconnecting temporarily from power. Upon powering back up symptoms remain.

Raised setpoint 0.6 degrees on Carel thermostat. Compressor continues to run, ice box temperature continues to drop.

Changed smart speed controller from Auto to Manual. Set compressor to slowest speed. Ice box temperature staying roughly constant - 0.8 degrees below setpoint. Compressor continues to run.

System consists of Frigoboat K50F compressor (Danfoss BD50) with keel cooler, Carel programmable T'stat, Compressor speed controller, evaporator coil.

I installed the system in 2005 and, aside from struggling a bit when in really demanding conditions (hot water and air temperatures), it has run reliably.

My guess is that the thermostat has failed, but perhaps there is an issue in the electronic module at the compressor.

Not sure how to proceed. At slow compressor speed box has dropped another 0.2 degrees while typing this. I am afraid I am going to freeze all the contents. What to do?

Do you have a mechanical thermostat or an electronic one? In any case case the sensor from the thermostat to see if it is free and clear.
We too have Frigaboat on our boat. I love it. You can call them. They are VERY nice about trying to figure out and suggest a fix for your unit.

[SeaSon]

Seems like you found the problem as the connectors. Clip off the old connectors and crimp on new connectors. Once they've overheated, the connection to the wire is compromised so they will 1) increase the current draw from your batteries and 2) reduce the voltage to the compressor. Both bad things.

[Tellie]

"I installed the system in 2005"

Well there's your problem, it's getting into it's teen years. They all start running wild then.


Halden Marine Services | Marine Watermakers, Solar Panels, Wind Generators

[redsky49]

I believe I may have identified the problem.

I had noticed earlier that both the positive and negative power supply wires felt really hot - more than they would be from the hot running compressor. Looking closer at the male/female connection (hate those spade connectors!) at the compressor I was real suspicious of what appeared to be overheating at one end. This was a 10g. wire that I had run about 24" from a terminal strip that serves the refrig. Measured voltage at the terminal strip was 12.9V. Couldn't safely get my probes into position to measure voltage directly at the compressor.

I also got my first red fault indicators this morning. Once for a failure of compressor to start, and later for low voltage

The underside of the connector appeared a bit darker than the part that was easily visible. Measured resistance was about 1.9 ohms of this wire portion. Replaced the wire with a new connection using 12g. (since that was readily available without searching throughout the boats lockers).

The result appears to be that the system is working properly. Wires are normal temperature, no fault signals, and running in auto mode without any issues.

This raises another issue and that is push-on spade terminals. I don't think that they are safe. Seven or eight years ago I had a push-on terminal overheat and catch fire (Wow did that catch my attention!!) on the small heat pump HVAC system we have. I have never had standard ring terminals fail unless they were immersed in water.

My thoughts are that many of these systems are intended for dual use in the RV world and corrosion due to salt air is not given the necessary attention by manufacturers. Push-on connectors are inexpensive for the manufacturers and take up little room. They also make it difficult to get probes safely in for diagnostics.

The take away from this? Check all push-on terminals.

[redsky49]

This is the offending wire. Outside the locker it is easier to see the discoloration - especially the underside.

[Stu Jackson]

Richard Kollmann has always said that 99+% of all fridge problems are electrical.

[transmitterdan]

Originally Posted by redsky49

This is the offending wire. Outside the locker it is easier to see the discoloration - especially the underside.

This crimp looks like it was not done correctly. The crimp appears mostly on the wire and not on the connector sleeve. I believe that is the crux of the problem. Use a proper crimp tool and adhesive lined shrink terminals. If shrink terminals are not available at least use a quality terminal not from a Walmart crimp kit.

[SV THIRD DAY]

Originally Posted by redsky49

Replaced the wire with a new connection using 12g. (since that was readily available without searching throughout the boats lockers).

The result appears to be that the system is working properly. Wires are normal temperature, no fault signals, and running in auto mode without any issues.

The take away from this? Check all push-on terminals.

Bingo....

The No 1 marine refrigeration issue...electrical issues by corrosion or Voltage Drops and Spikes. No one ever wants to believe it, but I hear these stories on a weekly basis doing trouble shooting.