12/24 Volt Boat Refrigerator’s Poor Performance Possible Causes

[sailingunity]

Originally Posted by Richard Kollmann

Adding too much refrigerant will always increase load on compressor. If too much refrigerant is added the high amperage load on compressor will stop compressor.
The EZKoll two plate system's refrigerant flow are normally controlled by an expansion valve. Did you locate this valve? If you can not find this valve your problem is going to be a little more difficult to solve.

I haven't found it yet but its a little tight in there, I'll probably find it once I remove the baffle.

[Richard Kollmann]

Originally Posted by sailingunity

I haven't found it yet but its a little tight in there, I'll probably find it once I remove the baffle.

We need to start over EZkold did sell systems with both types of refrigerant flow control devices Capillary tube and expansion valve.

The correct refrigerant charge on that two plate system after compressor has run more than 45 minutes will display a low side pressure of 12 to 14 psi. and hopefully amperage of no more than 5 1/2 amps. EZ Kold because of their additional water condenser has produced contaminants restricting refrigerant flow. So if low pressures are correct and amperage is too high we can assume refrigerant flow is restricted.


Report back after adjusting low pressure. When compressor stops then wait more than five minutes before restarting it.

[OzePete]

[QUOTE=Richard Kollmann;2744639]We need to start over EZkold did sell systems with both types of refrigerant flow control devices Capillary tube and expansion valve.

The correct refrigerant charge on that two plate system after compressor has run more than 45 minutes will display a low side pressure of 12 to 14 psi. and hopefully amperage of no more than 5 1/2 amps. Correct.

EZ Kold because of their additional water condenser has produced contaminants restricting refrigerant flow. ?? Please explain!

So if low pressures are correct and amperage is too high we can assume refrigerant flow is restricted. Wrong information, if there is a restriction or blockage the suction pressure will be lower and most likely the amperage will also be lower. This is unless the blockage is in the compressor discharge which is extremely unlikely

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

[Richard Kollmann]

[QUOTE=OzePete;2744977]

Originally Posted by Richard Kollmann

We need to start over EZkold did sell systems with both types of refrigerant flow control devices Capillary tube and expansion valve.

The correct refrigerant charge on that two plate system after compressor has run more than 45 minutes will display a low side pressure of 12 to 14 psi. and hopefully amperage of no more than 5 1/2 amps. Correct.

EZ Kold because of their additional water condenser has produced contaminants restricting refrigerant flow. ?? Please explain!

So if low pressures are correct and amperage is too high we can assume refrigerant flow is restricted. Wrong information, if there is a restriction or blockage the suction pressure will be lower and most likely the amperage will also be lower. This is unless the blockage is in the compressor discharge which is extremely unlikely

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

Pete, show the E Z Kold boater’s complete comments posted to your own qualified technician he or she will explain Non Destructive methods on identifying refrigerant flow problems from incorrect refrigerant charge. We know it is not complete refrigerant blockage. The test I suggested will help rule out oxide corrosion oil sludge restrictions that I believe caused E Z Kold to stop the boat refrigeration production.

[john61ct]

Just state your believed-true facts and opinions, and hopefully one day we fridge noobs will figure out who's right.

Insults are still insults even if you try to word them "subtly".

[OzePete]

[QUOTE=Richard Kollmann;2745368]

Originally Posted by OzePete

Pete, show the E Z Kold boater’s complete comments posted to your own qualified technician he or she will explain Non Destructive methods on identifying refrigerant flow problems from incorrect refrigerant charge. We know it is not complete refrigerant blockage. The test I suggested will help rule out oxide corrosion oil sludge restrictions that I believe caused E Z Kold to stop the boat refrigeration production.

Thanks for the (belittling) tip Richard but with over 57 years actually hands on experience in the refrigeration industry and 50 years of engineering refrigeration systems, I am more qualified than any of my qualified refrigeration staff.

And if any of my staff advised a client, quote: "So if low pressures are correct and amperage is too high we can assume refrigerant flow is restricted." or " High side pressure should never exceed 120PSI" they would not have a job.. simple.

Your highlighted advice that I corrected, was completely wrong Richard, regardless of how you try spin it!

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

[Richard Kollmann]

Pete, I do not know what high side pressure has to do with your employee keeping their job. High refrigerant pressure is controlled by the design of each system. High Back Pressure systems operate with pressures over 250 psi.

This thread deals with relation between amperage and low refrigerant pressure the actual high pressure is not known.

[Typhoon]

Originally Posted by Richard Kollmann

We need to start over EZkold did sell systems with both types of refrigerant flow control devices Capillary tube and expansion valve.

The correct refrigerant charge on that two plate system after compressor has run more than 45 minutes will display a low side pressure of 12 to 14 psi. and hopefully amperage of no more than 5 1/2 amps. EZ Kold because of their additional water condenser has produced contaminants restricting refrigerant flow. So if low pressures are correct and amperage is too high we can assume refrigerant flow is restricted.


Report back after adjusting low pressure. When compressor stops then wait more than five minutes before restarting it.

I have serviced quite a few of these EZKold systems lately and have not yet seen one with a TXV or TEV yet.

I did find that they used all sorts of different parts and that not two of these systems were ever the same . I also noted some innovative evaporator box designs. The quick connect couplers they used were prone to leakage. I had to remove them on a few systems and solder the connectors together .

Regards John.

[john61ct]

I take it use of "innovative" there is in a negative sense?

[Typhoon]

Originally Posted by john61ct

I take it use of "innovative" there is in a negative sense?

No, not at all. The stainless work I have seen is pretty good.

Regards John.

[sailingunity]

Originally Posted by ColdEh Marine

I have serviced quite a few of these EZKold systems lately and have not yet seen one with a TXV or TEV yet.

I did find that they used all sorts of different parts and that not two of these systems were ever the same . I also noted some innovative evaporator box designs. The quick connect couplers they used were prone to leakage. I had to remove them on a few systems and solder the connectors together .

Regards John.

IIRC that is the reason the PO selected EZKold, because the cold plates were sort of custom designed for the space. I'm not near the boat, but last time I looked in there I don't recall seeing anything but the refrigerant lines, and the thermostat wire - however I can't rule out that there might be a TXV in there. The PO bought the water / air cooled system and within a year or two removed the water cooled part because of the aforementioned issues. However to my knowledge it worked for him for the remaining 5 years he owned the boat, and for 6 months while I lived aboard until I tried to tweak the refrigerant to get both plates to frost over. Then things went south. It sounds to me like it might be wishful thinking to get both plates completely frosted over?

[Typhoon]

Originally Posted by sailingunity

IIRC that is the reason the PO selected EZKold, because the cold plates were sort of custom designed for the space. I'm not near the boat, but last time I looked in there I don't recall seeing anything but the refrigerant lines, and the thermostat wire - however I can't rule out that there might be a TXV in there. The PO bought the water / air cooled system and within a year or two removed the water cooled part because of the aforementioned issues. However to my knowledge it worked for him for the remaining 5 years he owned the boat, and for 6 months while I lived aboard until I tried to tweak the refrigerant to get both plates to frost over. Then things went south. It sounds to me like it might be wishful thinking to get both plates completely frosted over?

As Richard has said before , there may not be enough reserve capacity in the system to get those plates completely frozen . If this system is based on a BD35 or 50 with two holding plates and the insulation is old there may be more heat coming into the box then the compressor can remove and the system reaches an equilibrium. The next question is , does the system cycle off ?

Regards John.

[Richard Kollmann]

Originally Posted by ColdEh Marine

As Richard has said before , there may not be enough reserve capacity in the system to get those plates completely frozen . If this system is based on a BD35 or 50 with two holding plates and the insulation is old there may be more heat coming into the box then the compressor can remove and the system reaches an equilibrium. The next question is , does the system cycle off ?

Regards John.

I do not know if capacity is of issue here as refrigerant flow control seams to be where the problem is. Using capillary tube refrigerant flow is too limited for the wide temperature range of a eutectic plate especially with dual plates. The fixed temperature range of a capillary tube is set by its length and its interior inside full length orifice diameter. As high pressure liquid refrigerant is expanded into low pressure evaporator it only absorbs heat efficiently during the phase change to a vapor. If phase change does not extend through the full length of evaporator coil tubing evaporator/eutectic plate has greater negative COP. The problem with capillary tube refrigerant flow it is predetermined by tube selection, the small volume of refrigerant in system, compressor speed, and the variable of condenser cooling temperatures. Add a second plate to a cap tube flow control system will require correct refrigerant charge and longer compressor running time.

Eutectic plates in series and large single eutectics should not use Capillary Tube refrigerant flow control devices. Thermostatic Expansion Valves (TXV) and a refrigerant receiver tank allow the installation engineer to set the heat absorption phase change to cover complete evaporator without overloading compressor.

[Tbaker]

I have a Frigaboat Keel Cooler system that has been slowly showing signs of needing a recharge. I installed it myself in 2004 and it has taken us halfway around the world with no issues. Signs are evaporator box not chilling up more than one inch and unit running continually. I only hear the tinny refrigerant sounds for about 30 minutes then nothing. My Frigaboat has a service port on a horizontal tube attached near the top of the compressor and another mounted on a vertical tube that is attached to one of the tubes coming into/out of the unit. Can someone please tell me which one is the low pressure service port? I'd also like to know what the ballpark charge PSI should be so I don't overcharge. I have attached a picture of a Frigaboat that unit looks like mine.
Thanks in advance,
Tom

[Richard Kollmann]

Originally Posted by Tbaker

I have a Frigaboat Keel Cooler system that has been slowly showing signs of needing a recharge. I installed it myself in 2004 and it has taken us halfway around the world with no issues. Signs are evaporator box not chilling up more than one inch and unit running continually. I only hear the tinny refrigerant sounds for about 30 minutes then nothing. My Frigaboat has a service port on a horizontal tube attached near the top of the compressor and another mounted on a vertical tube that is attached to one of the tubes coming into/out of the unit. Can someone please tell me which one is the low pressure service port? I'd also like to know what the ballpark charge PSI should be so I don't overcharge. I have attached a picture of a Frigaboat that unit looks like mine.
Thanks in advance,
Tom

Without knowing what your compressor's preset speed is set for I would recommend adding Pure R134a refrigerant slowly until unit is drawing 5 amps and no more. Very slow leaks on Frigoboat units are do to using an actual flow moving Oring seal in each of the line connectors. See Frigoboat web site to obtain correct special seal.

Refrigerant low pressure in picture is the black or green cap above compressor dome. If after adding refrigerant and waiting a while evaporator's surface area does not display frost over 85% of its surface add a small amount of refrigerant. Too much refrigerant in system will display frost on return line towards compressor and compressor may not run the next time it tries to start.

Hopefully you did not add any moisture when servicing system, if so the hissing sound in evaporator will stop and the frost cover will disappear.