Wiring and plumbing diagram for 110V fridge with dual boxes

[phorvati]

Originally Posted by Richard Kollmann

You can test the valve settings and their flow by energizing only one solenoid at a time and monitoring system low and high pressures. WARNING DO NOT CLOSE BOTH SOLENOIDS AT THE SAME TIME AND BE READY TO STOP COMPRESSOR IF HIGH PRESSURE EXCEEDS 150PSI. Blockage of the single TXV operating will show up as very low system low pressure, 100% blockage will show a vacuum not a pressure. If it is the refrigerator TXV and refrigerator evaporator tested low correct pressure can be from 4 psi to 15 psi depending on valve size and evaporator temperature. Warm evaporator higher pressure, Cold lower pressure.

Richard, thanks for sharing your experience and knowledge. Its been very helpful. And your book has all the info. Im putting page markers along the line so i can get back to relvant descriptions or symptoms and observations. As far as my mistake #1, it may be that close loop was fine after submerge and system sitting neglected for many years and few owners. While this process I'm going through might be frustrating I feel that understanding refrigeration, just like understanding diesels is a must if you live on a boat. And no better way to get you feathers ruffled then going through this. So far I only knew cap tube based single loop bd50 system which is very simple. I am sort of peeling the onion with this more complex system especially with dual txvs and evaporators comming together on a suction side.
I am realizing i need to get rid of contamination before anything else. And that's where I'll start.

[Richard Kollmann]

Think of your system with one of the solenoids closed as a single loop system because that is the way it will perform. This single system you have created by stopping flow into the dead loop still has all it needs to operate one box correctly. If there is contaminated refrigerant or oil or solids they will travel through compressor, condenser, receiver, filter/dryer, one solenoid and one TXV. Now in this single loop should any component showing frost or be cooler it will indicate a restriction to refrigerant flow there. Only the TXV in the liquid side of system should be cold.

If you do run the unit as a single system using the refrigerator side only plot the high and low pressures regularly over several hours. If you determine there is blockage do my hot rage test on TXV. If that test fails to show moisture then there are solids or oil sludge restrictions in system or one of the King valves I see on your picture are not in the proper open/full close service port position

[phorvati]

So for whatever its worth after I shut off the system it equalized at 50psi and it remained overnight and pressure did not drop, i still had gauges on it 24h later.

I ended up replacing fridge TXV with a new one i already had, identical model Sporlan FJ-1/4-C.
New filter/dryer i put in is Alco ADK-162.

I took the opportunity to inspect the TXV screens and they were both clean.

I am not sure how one ensures nitrogen flows through in order to push air out? I pressurized High side service valve in middle position about 1 turn back from fully back seated(CCW). I let nitrogen out the low side service valve. Does compressor block the flow inside itself from high side to low side ensuring nitrogen is routed through entire loop instead of the short way through compressor? After I closed the suction side gauge I also cracked few flare fittings around evaporator plates to let nitrogen flow for at furthest points for a little while.

Then I re-pressurized with nitrogen to 150lbs and looked for leaks with soap solution and did not find any.

Ran a vacuum overnight and it held at close to 30in hg for 3 hours after i stopped the pump. So i am fairly certain there are no leaks.

[Richard Kollmann]

If the TXV temperature sense tubes are warm and solenoids are powered open nitrogen can be added to suction port and exhausted through the high side port. If you add pressure to high pressure port its flow is blocked by a read valve in compressor.

Holding 150 psi over night is a good leak test.

Your new compressor most likely has Ester oil in it. Ester oil likes moisture and under normal removal of atmospheric pressure of 30 inches refrigerant gauge pressure, oil will not easily release moisture. I have found the average refrigerant pump will require complete system be maintained at 100 degrees F or pump is left on over night. The alternative to this method is to have a Micron pressure meter and running pump for two hours at 200 microns or less.

[phorvati]

Originally Posted by Richard Kollmann

If the TXV temperature sense tubes are warm and solenoids are powered open nitrogen can be added to suction port and exhausted through the high side port. If you add pressure to high pressure port its flow is blocked by a read valve in compressor.

Holding 150 psi over night is a good leak test.

Your new compressor most likely has Ester oil in it. Ester oil likes moisture and under normal removal of atmospheric pressure of 30 inches refrigerant gauge pressure, oil will not easily release moisture. I have found the average refrigerant pump will require complete system be maintained at 100 degrees F or pump is left on over night. The alternative to this method is to have a Micron pressure meter and running pump for two hours at 200 microns or less.

That's very good to know, so it might be that compressor oil stores moisture. I left lamps in each box with lids closed while evacuating last night. Fridge digital thermostat was showing 82F. Compressor was around 80F on IR thermometer while vacuum pump was running. I am going to have to roll with what i did and look for symptoms of moisture after i start it again tonight. At least i know its leak free. If i find moisture again it will probably be due to what you just mentioned. That replacement compressor i got off ebay and ports were sitting exposed for few months. So its likely loaded with moisture. That might be my culprit.

I still have that mystery as to why original fridge TXV was failing? Screen was clean and it did not respond to heat indicating blockage might have been dirt, or just malfunction. But it did work for a while as fridge plate was getting frozen. Fridge TXV is Sporlan FJ-1/4-C which looks to be obsolete. I was able to find a new-open-box identical model on ebay which is whats in it the fridge right now. Freezer txv which responded good to heat (meaning likely moisture issue) appears to be Danfoss TN2. At least based on angled adjustment cap location. I did not change that one. One other thing I did not look into is how sensing bulb is attached. I think its at 12-o'clock position on both and i will just wrap each one in insulation so i don't skew the sensing feedback.

Earlier i said Txvs are in the 80-100$ range which lead me to try to use what i had. Danfoss TN2 is in the 50$ range which is more reasonable. i should have just bought two new TN2s.

[phorvati]

So I back and running. 125psi and 12psi. It's been like that for about 4 hours. This time I added ice to help bring box temps down. I had a little scare. Compressor stopped working. Fan was on. So I think thermal overload kicked in. Not sure when it happened but I restarted compressor and opened the floorboard where condenser is located. Any idea at what temperature does the thermal overload occur?

What is more likely to cause thermal overload, mosture/sludge buildup or low oil. I am really not sure if this compressor was shipped with oil drained or partially drained or full. Any idea on how to go about checking this?

[Richard Kollmann]

Originally Posted by phorvati

So I back and running. 125psi and 12psi. It's been like that for about 4 hours. This time I added ice to help bring box temps down. I had a little scare. Compressor stopped working. Fan was on. So I think thermal overload kicked in. Not sure when it happened but I restarted compressor and opened the floorboard where condenser is located. Any idea at what temperature does the thermal overload occur?

What is more likely to cause thermal overload, mosture/sludge buildup or low oil. I am really not sure if this compressor was shipped with oil drained or partially drained or full. Any idea on how to go about checking this?

Sorry phorvati, when I first read your posts I thought I could help but I now see I need to find other projects that have quicker solutions. At almost 86 years old I do not have enough time left to see your system operate correctly. Non destructive evaluation should always come before going in circles making changes based on non confirmed guesses. The rusted compressor could have been used to test the rest of the system for problems before changing it. It is too late now to understand an open probably used compressor's Ester oil should replaced. The recommendation on this oil is to discard oil if exposed to the air for more than fifteen minutes. The two TXVs connected to one holding plate is also confusing. Changing the lower valve without confirming it was blocked by isolating it and monitoring low pressure was another mistake.

Before leaving you to the other problems I have no answer to your questions about total oil quantity in compressor and how much is spread out in the rest of system. If the new compressor had the correct amount of oil in it and you removed all the most likely old mineral oil from receiver and holding plates oil quantity would not be a problem. The only way now to check oil level is to open up the system and drain it before putting the correct amount back in compressor.

[phorvati]

Originally Posted by Richard Kollmann

Sorry phorvati, when I first read your posts I thought I could help but I now see I need to find other projects that have quicker solutions. At almost 86 years old I do not have enough time left to see your system operate correctly. Non destructive evaluation should always come before going in circles making changes based on non confirmed guesses. The rusted compressor could have been used to test the rest of the system for problems before changing it. It is too late now to understand an open probably used compressor's Ester oil should replaced. The recommendation on this oil is to discard oil if exposed to the air for more than fifteen minutes. The two TXVs connected to one holding plate is also confusing. Changing the lower valve without confirming it was blocked by isolating it and monitoring low pressure was another mistake.

Before leaving you to the other problems I have no answer to your questions about total oil quantity in compressor and how much is spread out in the rest of system. If the new compressor had the correct amount of oil in it and you removed all the most likely old mineral oil from receiver and holding plates oil quantity would not be a problem. The only way now to check oil level is to open up the system and drain it before putting the correct amount back in compressor.

No worries, thnaks for all your knowledge thusfar. So far thigs are workng 14 hours into it. This is a learning process for me. I will learn from mistakes I made and hopefully these can help someone else. If this thing keeps shutting down I might use original compressor. I have the vales to isolate it and It's identical.
How much frost should there be on txvs?

[Coolerking]

Frost is normal on TXV.

[Uncle Bob]

Originally Posted by phorvati

No worries, thnaks for all your knowledge thusfar. So far thigs are workng 14 hours into it. This is a learning process for me. I will learn from mistakes I made and hopefully these can help someone else. If this thing keeps shutting down I might use original compressor. I have the vales to isolate it and It's identical.
How much frost should there be on txvs?
Attachment 198490Attachment 198491

You need to find an actual manufacturer of refrigeration products that is willing and prepared to assist you, rather than "expert", this site used to have a number of them however they have been chased off or excommunicated, so good luck.

[Coolerking]

Originally Posted by Uncle Bob

You need to find an actual manufacturer of refrigeration products that is willing and prepared to assist you, rather than "expert", this site used to have a number of them however they have been chased off or excommunicated, so good luck.

Howdy, I actually do build refrigeration systems for a living.
From scratch.
The systems in nearly every boat/yacht are the simplest type found in the industry.
Its all about the basics and best practice.

I will always try and help out, no preconceptions, no bs.

I have been in the marine industry as a Professional sailor, boat builder, USCG Capt, for more than 30 years, so I know a little, and enough to know when to ask for help.

Learning something new everyday is what I strive for, whether that's on this forum, or on the 120 foot motor yacht I'm leaving for right now.




The issue he is having is tough to diagnose because the starting point is in question.

We will find a fix.

[phorvati]

Just wanted to put an update. We've been away on a mini cruise/vacation with the boat for 8 days now. And the system is doing fine. I run the generator 4-5h per day and freezer is doing very well. Fridge needs some adjustment. It's still holding milk and meats in good condition. Freezer ended up freezeing bunch of meats we packed on day 1 so that's pretty good. What I found is that compressor thermal protection shuts it down if engine room is hot. I.e it did shut down few times but that was because I turned it on right after a long motoring session. So part of my issue is location of condenser unit which is under floorboards and just aft of Transmission. I need better way to remove heat from the area which seems to be trapped. 8 days ago engine wasn't running but it was very hot down there and heat had nowhere to go.
Some of the other stuff is box related. I realized there is an open drain at the bottom of both fridge and freezer, so that let's a lot of cold out. With fall comming I belive it should run fine. I'm going to let that confirm my hypothesis before making adjustments. Was thinking that adding a water cooled loop would help keep compressor from overheating. Hottest temperature I got on IR was in the 180F range which is from what I understand far away from danger point as far as oil lubrication is concerned.
I could not find out what temperature that thermal overload protector engages, the one mounted inside the terminal box and against compressor body. They way I mounted condenser unit, it's impossible to get a IR reading on that side. It's against the bulkhead on oposite side. I would have to rotate condenser tray.