Fridge -- danfoss compressor 3-blink code

[sailingharry]

Regarding the pressures:


* Static pressure of 100 PSI corresponds to a temperature of 85, if there is any liquid present. Ambient temps were around 85. Unless there should be no liquid present when off?
* Low pressure of 0 is about 2-3 PSI below SeaFrost recommended setpoint for the Constant Pressure Valve (serves at TXV). They recommend -2 to -5 F, a temperature not a pressure, but -2 to -5 is about 4-6 PSI. The 0 PSI I have is -10 to -15 -- if my gauges are accurate to +/- 5 PSI! http://www.seafrost.com/Valve%20issues.html
* The high pressure of 150 corresponds to a temperature of 150F -- and since I am obviously running it with the cover off to get these readings, I have low flow over the condenser. This would show a 70F delta (air to refrigerant). Is that unreasonable? Not sure.
* 7 hours in, with box at 35, my high pressure was 175, for a temperature of about 120F. That seems quite reasonable.
* The fact that the low side pressure never wavered from 0PSI (within optical resolution) as box went from 45F to 35F seems to imply that the constant pressure valve is maintaining "constant pressure."


I'm going to try and get running amps today.

[Richard Kollmann]

Originally Posted by sailingharry

Regarding the pressures:


* Static pressure of 100 PSI corresponds to a temperature of 85, if there is any liquid present. Ambient temps were around 85. Unless there should be no liquid present when off?
* Low pressure of 0 is about 2-3 PSI below SeaFrost recommended setpoint for the Constant Pressure Valve (serves at TXV). They recommend -2 to -5 F, a temperature not a pressure, but -2 to -5 is about 4-6 PSI. The 0 PSI I have is -10 to -15 -- if my gauges are accurate to +/- 5 PSI! Valve Issues
* The high pressure of 150 corresponds to a temperature of 150F -- and since I am obviously running it with the cover off to get these readings, I have low flow over the condenser. This would show a 70F delta (air to refrigerant). Is that unreasonable? Not sure.
* 7 hours in, with box at 35, my high pressure was 175, for a temperature of about 120F. That seems quite reasonable.
* The fact that the low side pressure never wavered from 0PSI (within optical resolution) as box went from 45F to 35F seems to imply that the constant pressure valve is maintaining "constant pressure."


I'm going to try and get running amps today.

Sailingharry, it spears you are the smartest person responding to this mixed up OP.
Regardless of ambient temperature of 85 degree is my concern for 175 psi high pressure. This generally results in excessively high compressor and oil temps. Now the question that needs an answer is, Why at 175 psi and evaporator is cooling why is compressor temperature not externally HOT?

The place to begin is removing refrigerant and evaporator pressure regulating valve and placing valve and and refrigerant. But before putting refrigerant back in Dehydrate system.

[sailingharry]

Richard,


Thanks for the compliment on my response. However, I'm not responding TO the OP -- I AM the OP! LOL.


The specifics of a Danfoss unit are not something I'm skilled with. However, a few decades ago I graduated from a respectable college with a degree in Mechanical Engineering, so at one time I actually knew a thing or two about refrigeration cycles, heat transfer, and material properties. But that's been a long time -- and there is a world of difference between book learning and field practice ... LOL.

[OzeLouie]

Originally Posted by Richard Kollmann

It may be your industry standard to assume it won't stick again, maybe in Tim buck too. I prefer a final fix just ask the boat owner what he thinks. Frigoboat has proven excessive high refrigerant pressure over time leads to purchasing a new refrigeration system. Try a search of this forum and see for yourself the disappoint created by operating excessive high pressure with a Danfoss BD compressor.
If you want to know why leaving gauges on with system OFF ask your engineer Mr Green he will explain it.

So despite efforts by myself and others to be friendly, have threads stay on track and to not digress to petty sniping, here again you revert to your normal MO of childish attempts to discredited others, their company, their products, their qualifications and now their location! What is your problem?

[OzeLouie]

Originally Posted by sailingharry

Regarding the pressures:


* Static pressure of 100 PSI corresponds to a temperature of 85, if there is any liquid present. Ambient temps were around 85. Unless there should be no liquid present when off?
* Low pressure of 0 is about 2-3 PSI below SeaFrost recommended setpoint for the Constant Pressure Valve (serves at TXV). They recommend -2 to -5 F, a temperature not a pressure, but -2 to -5 is about 4-6 PSI. The 0 PSI I have is -10 to -15 -- if my gauges are accurate to +/- 5 PSI! Valve Issues
* The high pressure of 150 corresponds to a temperature of 150F -- and since I am obviously running it with the cover off to get these readings, I have low flow over the condenser. This would show a 70F delta (air to refrigerant). Is that unreasonable? Not sure.
* 7 hours in, with box at 35, my high pressure was 175, for a temperature of about 120F. That seems quite reasonable.
* The fact that the low side pressure never wavered from 0PSI (within optical resolution) as box went from 45F to 35F seems to imply that the constant pressure valve is maintaining "constant pressure."


I'm going to try and get running amps today.

There is a lot of confusion regards R134a refrigeration system operating temperatures. (Applying the KISS principle here!)

Temperature and pressure are related and this relationships data is available via a P-T charts. (Good ones are in metric and imperial)

Evaporator: The evaporator is the ‘Heat collector! The evaporator’s gas has to be colder than the area to be refrigerated so that heat from the area can be absorbed by the evaporating gas. (Heat travels towards colder area) Therefore the evaporator (Low side) operates usually between 5C and 25C lower than the area to be refrigerated. If this was not happening then no heat would be collected and therefore no cooling!

Condenser: The condenser is the ‘Heat disposer! The condenser’s gas has to be much hotter than the air or water in which heat is to be disposed of. Typically an air cooled unit will see condenser gas temperatures 10C to 20C higher than the air temperature and water cooled 5C to 10C higher.

Now the Harry situation: Given that the ambient reported is (85F) 30C and we add 20C TD., the condensing gas is at 50C or 176PSIG which is correct and as reported. So you are spot on Harry, you’s the Guru!

And ignore any suggestion that such head pressure is ‘damaging etc etc because it simply is not: It needs to be noted that near all compressor manufacturers refer to a condensing temp of 55C (204PSITG) in their data for R134a! See extract from Danfoss BD50 data pictured. Talk of condenser pressures not exceeding 130PSIG indicates a lack of understanding of the basic fundamentals of refrigeration.

[sailingharry]

So here's the current situation.

The fridge ran on Stat overnight, holding a box temp of about 35F -- our target.

We leave for the summer on Friday, and there's 1000 things still broken -- the head (toilet, not evaporator pressure) issue was fixed this afternoon....

I'm going on the theory that the unit was overcharged, and connecting the high side gauges let out enough gas to resolve it.

Fallback is the system still can function as a spillover -- and besides, we are heading north (Maine and hopefully Canada)

I'll monitor it, but for now I'm calling it "not a high priority" (that's not quite calling it "fixed!"), and moving on to higher priorities.

Thanks all for the helpful thoughts and input. I learned a lot.

[Richard Kollmann]

I wish someone would explain I can not get through that compressing mole-ques of refrigerant gas creates heated gas. A topical refrigeration design will include a condenser sized to liquefy the gas while maintaining sufficient differential pressure acrouss the refrigerant flow control device. In this Seafrost system refrigerant flow is controlled by maintaining fixed evaporator temperatures in order to achieve a specific box temperature at a higher temperature than the evaporator.
I have explained how the small compressor now I will give you the actual pressuire and their temperature as refrigerant flows through system.
Refrigeration is not running Standard temperature 60 degrees F. Correct charge of refrigerant in system will display a high and low pressure depending on system hardware temperature a pressure on both sides of 50 to 60 PSI with R134A.

1. Upon compressor starting with every part of system warm it will take a full ten minutes refrigerant to stabilize around a low pressure of 8 to 12 psi and high pressure of 120 psi.
2. Because this system uses a LPR valve to control flow at 20 minutes high pressure will be stable at 120 plus with a refrigerant temperature after condenser 115 to to 125 degrees. At this point of time low pressure regulator will try to maintain the factory preset low pressure. Design for refrigerator evaporator might be +12 degrees. The pressure interring pressure regulator 120 or if there is much heat to be removed from box high pressure could reach 135 psi.
3. Evaporator temperature will become stabilized by low pressure preset valve.
The compressor temperature should be limited to 130 degrees F when possible because it relies on sub cooled returning temperature from evaporator.

Wrong instructions can cause those asking for help bad Bad information leads to major disappointment.
Many of us helping Skip on Flying pig a few years back, you can look it up, we created a year and more troubles for Skip and his Wife.

We all can give incorrect advice but now is a game to I suppose just to get attention or mislead for fun. No wonder the experts From manufactures do not like to participate. There seams to be enough monitors following this forum where have they bin lately?

[Richard Kollmann]

I enjoy, I admit the emails I get for my time spend in helping boaters every day. So you can see why I am responding this morning Louie to your hateful criticism of my technical knowledge. I should post your discussing mail to me this morning but no I will save it as it because it is legal free speech.

Talk about complacence an technical ability I do apologize for to quickly expressing my anger last night my mind was ahead of my typing but hopefully you got the point, or you would not have attacked visually me today. Your advice in an attempt to sell your product is usually counter productive, you might say harmful to others. I hope the rest of my day is better.

To stay with this thread your arrow on post 35 relates to condenser temperature and not refrigerant temperature the excessive pressure created by compressor remains the same after leaving condenser. What was point of using chart?

[OzeLouie]

Originally Posted by Richard Kollmann

I enjoy, I admit the emails I get for my time spend in helping boaters every day. So you can see why I am responding this morning Louie to your hateful criticism of my technical knowledge. I should post your discussing mail to me this morning but no I will save it as it because it is legal free speech.

Talk about complacence an technical ability I do apologize for to quickly expressing my anger last night my mind was ahead of my typing but hopefully you got the point, or you would not have attacked visually me today. Your advice in an attempt to sell your product is usually counter productive, you might say harmful to others. I hope the rest of my day is better.

To stay with this thread your arrow on post 35 relates to condenser temperature and not refrigerant temperature the excessive pressure created by compressor remains the same after leaving condenser. What was point of using chart?

As I posted (P34) you use every opportunity to denigrate anyone you perceive as a threat to your ‘dictatorship, but this time you have stooped to a new low.
My PM to you was out of genuine concern and respect for a fellow industry member specially after reading your rather indecipherable post 37!
You have twisted that PM into something dirty and used it against me without actually exposing it so I shall:

PM to Richard Kollmann:

Hi Richard, I write this to you as a matter of genuine concern.

We have been in a Covid19 lock down here for two weeks and unable to work so I have spent time studying past CF posts and it is obvious that you have contributed considerably and earned a reputation accordingly.

In my opinion your recent comments have become quite irrational and technically incorrect, yet understandable at your age. There are those in this industry making fun of your comments, but I find it sad.

I would strongly suggest that you get your posts vetted so as to not ruin the reputation you have earned.

Regards OzeLouie (Louie Mackay)

Now how in hell do you can twist that into 'hateful criticism' ?

[Coolerking]

Ok gang. this is way above my pay grade, and frankly kinda strange.
Too busy to get dragged into stuff like this.
I do this for a living, have been in the industry for 30 years, both as a professional sailor, boat captain, and now for 18 years a Marine industry Refrigeration and HVAC tech handling all of the Southern California area.

Those of you who have contacted me via Pm please continue to feel free to do so.
I won't be offering any more public assistance with any of the HVAC issues on this or any other posts going fwd as its just not effective.
If you need help, PM me and I will do my best to advise.
Hope you all find the winds fair and the seas following!

[Richard Kollmann]

Originally Posted by Coolerking

Ok gang. this is way above my pay grade, and frankly kinda strange.
Too busy to get dragged into stuff like this.
I do this for a living, have been in the industry for 30 years, both as a professional sailor, boat captain, and now for 18 years a Marine industry Refrigeration and HVAC tech handling all of the Southern California area.

Those of you who have contacted me via Pm please continue to feel free to do so.
I won't be offering any more public assistance with any of the HVAC issues on this or any other posts going fwd as its just not effective.
If you need help, PM me and I will do my best to advise.
Hope you all find the winds fair and the seas following!

Coolerking, I am but one of the followers of marine refrigeration that will be disappointed that you decided not to participate here. Only a qualified technician’s experienced with various types of marine refrigeration can provide the wide range of open answers to real questions here. In the future I am sure we all will PM you for help and advice.

[Uncle Bob]

Originally Posted by Coolerking

Ok gang. this is way above my pay grade, and frankly kinda strange.
Too busy to get dragged into stuff like this.
I do this for a living, have been in the industry for 30 years, both as a professional sailor, boat captain, and now for 18 years a Marine industry Refrigeration and HVAC tech handling all of the Southern California area.

Those of you who have contacted me via Pm please continue to feel free to do so.
I won't be offering any more public assistance with any of the HVAC issues on this or any other posts going fwd as its just not effective.
If you need help, PM me and I will do my best to advise.
Hope you all find the winds fair and the seas following!

Hey, I fully understand your sentiment, there have been a number of refrig techs and manufacturers that have either bailed or been chased away from this site over the last few years, sad really as the forum is the poorer for their departure.

[SemperAvanti41]

I have had many problems with refrigeration on boats over the years. The first thing I would do is swap out the Secop controller with either a new one or one that is currently working. A new one goes for $163.00 and sooner or later your going to need one anyway. Also the new ones seem to use less power.

[OzeLouie]

Originally Posted by SemperAvanti41

I have had many problems with refrigeration on boats over the years. The first thing I would do is swap out the Secop controller with either a new one or one that is currently working. A new one goes for $163.00 and sooner or later your going to need one anyway. Also the new ones seem to use less power.

Yes the new Motor Driver Modules (MDM) have 'soft start' This allows the compressor motor to start slowly with much lower current draw, far more efficiently and less troublesome than the older MDMs that stress everything with their massive high albeit momentary start current.
I don't believe the MDM is Harry's problem but good to have a spare specially if he still has the older troublesome one.

[Richard Kollmann]

Harry now thinks his extreme high high side pressure after removing some refrigerant solved his problem. I wish he had reported operating low pressure before ending his reporting. My guess is if valve is not replaced or correctly adjusted Cleave next time will be contacted.