There isn't any videos hardly at all, describing how these work. Teach me what you know And then please explain how to build one DIY style. I've got something I need to keep on the ultra down low. Seriously though fantastic video I'm really pleased to see a video like this one. Thank you very much for the great tutorial
What you're calling an expansion tank I know as a liquid receiver. And usually the valve on the outlet of the receiver is closed when the system is off or when there isn't a call for refrigeration. I know it as a liquid line solenoid valve or a pump down solenoid. When it closes, liquid is drawn out of the line after the valve through the rest of the system back through the condenser and stored into the receiver until the next call when the valve opens up. Does the properties of the components change with cascade systems? I'm well versed in low, medium and high temp refrigeration but never worked on ultra low. Would like to know more if possible.
Hi, Topher! First the expansion tanks are only used on older ULT freezers and when newer models came out the expansion tanks were eliminated. Secondly here is information directly from the manufacturer's manual: "9) When the control sensor sees -35C, the expansion tank solenoid valve opens, releasing the extra refrigerant trapped in the tank. Remember this is a normally open valve, voltage will be turned off to allow the valve to open. Note: if the control sensor sees -25C or warmer the valve will be reenergized closed." The primary purpose of the expansion tank adds additional refrigerant to the system only after it has reached, is near, or at least is approaching, its operating point.
So the two stages have different refrigerants. Stage 1 evaporator cools the stage 2 condenser via the heat exchanger? I think i understand it. A diagram would have been helpful as i don't understand how they can share components. Great video though, very interesting
Good day, Sir. Actually we are now doing a research about 2 stage cascade refrigeration system too. And for the pairs of refrigerant, we tested 3 pairs for us to choose which is more suitable to attain a -80 C . May I ask on how we choose the best? what we need to considered? thank you
Hi! Every manufacture's piece of equipment has a nameplate on what refrigeration should be used as well as the amount, this should always be followed. For ultra low temperatures, the two most commonly refrigerants are 1st stage R-290 (trace amount) and R-404A 2nd stage R-508b.
Aren't tge liquid refrigerant receiver tanks and associated solenoids meant for system pumpdown? With such large temperature differentials in each loop I'd assume that is one of the main problems here, no?
Hi! The additional refrigerant provided by the expansion tank increases the charge of refrigerant in the refrigerant fluid path of the system to thereby provide additional cooling capacity to the system.
i have same model and er07 appears on screen and not going away though the cooling is really well but er07 is not going away.recently changed the batteries and still this er07 persist. any solution for this?
Hi, Fawad Ahmad! It appears to be related to one of the circuit boards or a bad cable. One thing we would try first, is to clear the alarm by pushing the alarm reset button. If this doesn't work, then we would power off the unit including turning off the battery and unplugging the machine for approximately 10sec. Hope this helps.
This is a very informative video for me. Can you please let me know the Gas pressure ranges for the lower and higher stage compressors.? 1- Suction line pressure 2- Delivery line pressure 3- Stand by pressure
I can't see any service valves how do you guys brake in to the system line tap ? Also dose the system run in defrost Hot gas or electrical ? I would to see the heat Exchanger inside the unit maybe next video Whats the Refrigeration unit uses
Hi! For question 1: We usually use piercing valves to check the charge, but we only do this if we are going to evacuate and recharge the refrigeration system anyway. We use them just as a temporary tap to check pressure and recover the refrigerant. We don't like leaving them in because of the leak risk. We then braze in a Schrader valve as our permanent access to the system; because if we have to service them again we have easy access to the system. We do very little field service, so this works well for us in our shop. But for field service this would be inconvenient if not impossible. So, we think in that case you would use a piercing valve to service the system, then you would crimp, cut, and braze the line to seal the system. For question 2: We have only seen them use electric heaters for defrost, and that is only for door defrost.
Hi! We have a blog about ULT Freezers here that might help answer your question: newlifescientific.com/blogs/new-life-scientific-blog/how-does-a-ult-freezer-work If you have further question/s, please don't hesitate to email us at cs@newlifescientific.com.
1st stage 200/0 with an ambient temperature of 75f (23c) the 2nd stage 100 - 125 / 12-18” when the unit is at -80c. These reading are with the new compressor that Thermo installed into the freezers after repair NT2212GKV as the old compressors RF41C5E are no longer manufactured.
Hi! Those are the leads from the ~6 thermocouples that are placed in various points throughout the refrigeration system to monitor performance. On certain models, thermocouples 1/2:1st Stage Heat Exchanger, thermocouple 3: 2nd Stage Evaporator Inlet, thermocouple 4/5: 2nd Stage Evaporator Outlet, thermocouple 6: Suction port 2nd Stage Compressor. Monitoring these will help diagnose the majority of the problems you will encounter with these freezers.
Hi! Maybe, but if it was possible it would likely take many stages (normal ULT cascade uses 2). We're not sure which refrigerants could/would be used for that. Liquid nitrogen and liquid helium is used for extremely low temperature applications.
Bom dia meu nome é Paulo Cezar Ziemer e tenho uma dúvida: se eu tiver um furo no primeiro estagio o que eu poderia fazer Good morning my name is Paulo Cezar Ziemer and i have a question if i heave a hole in the frist stage what can i do?
Hi, Paulo! 1st: The hole would have to be repaired and the filter drier would need to be replaced 2nd: First stage would need to be pressure tested with nitrogen, to verify there are no leaks. 3rd: Evacuate the 1st stage using a vacuum pump. 4th: Add refrigerant to the first stage according to the manufacture requirements listed on the machine. If you need more help, please don't hesitate to contact our live chat on our website (www.newlifescientific.com) or email us at cs@newlifescientific.com
Hi! Typically the refrigerant used in the 2nd stage (low stage) is R508b (with a little R404a or R290 to improve the miscibility of the oil and refrigerant). Newer Thermo freezers are starting to use R170 as the 2nd stage refrigerant.
I bet they made the stage two share stage ones condenser to help cool the refrigerant before stage one evap exchanges heat from stage two lowering the heat load on stage one. Efficient. Balance.
We currently have a -80c freezer that is liquid cooled and it keeps having issues maintaining temperature. Does the second stage suction line temperature have a role in this? We see an identical model with a much higher temperature for this component than our freezer when it's struggling to maintain -80c.
Hi! Diagnosing a freezer based on a statement is very difficult. 1stage primary/only function is to cool the 2nd stage. The 2nd stage function is to cool the actual freezer space. We would start with the simple steps, verifying that the filter is clean, proper airflow around the freezer, and then look into the refrigeration system. Usually when the freezer is struggling to maintain temperature the second stage is probably in need of service. Initial steps would include, insulation integrity, refrigerant possibly low, if these initial steps did not correct the problem then the second stage would be completely serviced. Which would be to remove the compressor and flush the oil, replace the filter drier, then pressure test and recharge the system.
Hello, In all of the ULT freezers we've had, the evaporator is actually copper pipes spread throughout the body of the freezer around the chamber. As such, there are no fans. Hope this helps!
awesome channel my man, So cool to see a proper detailed rundown of these cascade/science equipment. Keep it up
Thank you sir for good detail information...now i understand how to 1stage and 2 stage refrigrant..good sharing..nice to meet you sir...
VERY INTESTING THIS TYPE OF MACHINE GREAT
Great video. Thank you for making the corrections, it was even a good exercise to figure out what they where pointing out.
Hi Francisco,
Thanks for watching! Glad you enjoyed it.
There isn't any videos hardly at all, describing how these work.
Teach me what you know
And then please explain how to build one DIY style.
I've got something I need to keep on the ultra down low.
Seriously though fantastic video I'm really pleased to see a video like this one.
Thank you very much for the great tutorial
Basically using the evaporator of one system to cool the condenser of the other system.
What you're calling an expansion tank I know as a liquid receiver. And usually the valve on the outlet of the receiver is closed when the system is off or when there isn't a call for refrigeration. I know it as a liquid line solenoid valve or a pump down solenoid. When it closes, liquid is drawn out of the line after the valve through the rest of the system back through the condenser and stored into the receiver until the next call when the valve opens up. Does the properties of the components change with cascade systems? I'm well versed in low, medium and high temp refrigeration but never worked on ultra low. Would like to know more if possible.
Hi, Topher! First the expansion tanks are only used on older ULT freezers and when newer models came out the expansion tanks were eliminated. Secondly here is information directly from the manufacturer's manual:
"9) When the control sensor sees -35C, the expansion tank solenoid valve opens, releasing the extra refrigerant trapped in the tank. Remember this is a normally open valve, voltage will be turned off to allow the valve to open. Note: if the control sensor sees -25C or warmer the valve will be reenergized closed."
The primary purpose of the expansion tank adds additional refrigerant to the system only after it has reached, is near, or at least is approaching, its operating point.
So the two stages have different refrigerants. Stage 1 evaporator cools the stage 2 condenser via the heat exchanger? I think i understand it. A diagram would have been helpful as i don't understand how they can share components. Great video though, very interesting
Good day, Sir. Actually we are now doing a research about 2 stage cascade refrigeration system too. And for the pairs of refrigerant, we tested 3 pairs for us to choose which is more suitable to attain a -80 C . May I ask on how we choose the best? what we need to considered? thank you
Hi! Every manufacture's piece of equipment has a nameplate on what refrigeration should be used as well as the amount, this should always be followed.
For ultra low temperatures, the two most commonly refrigerants are 1st stage R-290 (trace amount) and R-404A 2nd stage R-508b.
Aren't tge liquid refrigerant receiver tanks and associated solenoids meant for system pumpdown? With such large temperature differentials in each loop I'd assume that is one of the main problems here, no?
Hi! The additional refrigerant provided by the expansion tank increases the charge of refrigerant in the refrigerant fluid path of the system to thereby provide additional cooling capacity to the system.
What refrigerants are used in these system ? I would guess R404A or R290 and R1150.
And how does 2. stage know when to use the buffer.
Hi! R404a 1 stage and R-290 & R-508B 2nd stage are the most common, but it's best to check your specific freezer for the correct refrigerant.
@@newlifescientificinc.789 I don't do ULT, just refrigeration, icemaker, slushice.
But how/when does it know to use the buffer ?
What refrigerant do these systems use?
Do both stages use different refrigerants?
Hi snapdragon,
Most of the ULT freezers we see use R404a in the first stage and R508b in the second stage. This is a fairly standard configuration.
@@newlifescientificinc.789 R290 is found in them also.
what kind of insulation material is needed to insulate tubings properly? what is the glue and tapes used for refurbishing the unit? thank you.
Hi! K-Flex closed cell foam pipe insulation tape: www.supplyhouse.com/K-Flex-800-EL-018-Elastometric-Insulation-Tape
i have same model and er07 appears on screen and not going away though the cooling is really well but er07 is not going away.recently changed the batteries and still this er07 persist. any solution for this?
Hi, Fawad Ahmad! It appears to be related to one of the circuit boards or a bad cable. One thing we would try first, is to clear the alarm by pushing the alarm reset button. If this doesn't work, then we would power off the unit including turning off the battery and unplugging the machine for approximately 10sec. Hope this helps.
This is a very informative video for me.
Can you please let me know the Gas pressure ranges for the lower and higher stage compressors.?
1- Suction line pressure
2- Delivery line pressure
3- Stand by pressure
Hi! Pressures differ from manufactures and types of refrigerants. No one size fits all answer.
I can't see any service valves how do you guys brake in to the system line tap ?
Also dose the system run in defrost Hot gas or electrical ?
I would to see the heat Exchanger inside the unit maybe next video
Whats the Refrigeration unit uses
Hi! For question 1:
We usually use piercing valves to check the charge, but we only do this if we are going to evacuate and recharge the refrigeration system anyway. We use them just as a temporary tap to check pressure and recover the refrigerant. We don't like leaving them in because of the leak risk. We then braze in a Schrader valve as our permanent access to the system; because if we have to service them again we have easy access to the system. We do very little field service, so this works well for us in our shop. But for field service this would be inconvenient if not impossible. So, we think in that case you would use a piercing valve to service the system, then you would crimp, cut, and braze the line to seal the system.
For question 2:
We have only seen them use electric heaters for defrost, and that is only for door defrost.
how it works 8:38
Hi! We have a blog about ULT Freezers here that might help answer your question: newlifescientific.com/blogs/new-life-scientific-blog/how-does-a-ult-freezer-work
If you have further question/s, please don't hesitate to email us at cs@newlifescientific.com.
Ak sath dono compresar nahi chal rha hai kya problem ho Santa hai
what should pressures be?
1st stage 200/0 with an ambient temperature of 75f (23c) the 2nd stage 100 - 125 / 12-18” when the unit is at -80c. These reading are with the new compressor that Thermo installed into the freezers after repair NT2212GKV as the old compressors RF41C5E are no longer manufactured.
Thank you for the series of videos! By any chance do you know what the red / blue wires you can see @4:50 next to the battery are for?
Hi! Those are the leads from the ~6 thermocouples that are placed in various points throughout the refrigeration system to monitor performance. On certain models, thermocouples 1/2:1st Stage Heat Exchanger, thermocouple 3: 2nd Stage Evaporator Inlet, thermocouple 4/5: 2nd Stage Evaporator Outlet, thermocouple 6: Suction port 2nd Stage Compressor. Monitoring these will help diagnose the majority of the problems you will encounter with these freezers.
@@newlifescientificinc.789 Thank you so much for this information. 👍
Is it possible to get a cascade system down to minus 270 degrees Celsius??
Hi! Maybe, but if it was possible it would likely take many stages (normal ULT cascade uses 2). We're not sure which refrigerants could/would be used for that. Liquid nitrogen and liquid helium is used for extremely low temperature applications.
What are you trying to make? Liquid hydrogen? Btw. I heard minus 270 degrees celsius can only be achieved by cascaded ammonia systems.
Bom dia meu nome é Paulo Cezar Ziemer e tenho uma dúvida: se eu tiver um furo no primeiro estagio o que eu poderia fazer
Good morning my name is Paulo Cezar Ziemer and i have a question if i heave a hole in the frist stage what can i do?
Hi, Paulo!
1st: The hole would have to be repaired and the filter drier would need to be replaced
2nd: First stage would need to be pressure tested with nitrogen, to verify there are no leaks.
3rd: Evacuate the 1st stage using a vacuum pump.
4th: Add refrigerant to the first stage according to the manufacture requirements listed on the machine.
If you need more help, please don't hesitate to contact our live chat on our website (www.newlifescientific.com) or email us at cs@newlifescientific.com
I wished for more, flow diagram through all components especially after correction. Otherwise it’s good to see the components
What is the freon of the 2nd stage that make temp - 80 C and which freon type can work with 404a comp
Hi! Typically the refrigerant used in the 2nd stage (low stage) is R508b (with a little R404a or R290 to improve the miscibility of the oil and refrigerant). Newer Thermo freezers are starting to use R170 as the 2nd stage refrigerant.
I used old R23 in second stage now is banned in Europe ! newone substitut produced TEGA GERMANY!😊 GERMANY
Awesome video dude, appreciate it.
I bet they made the stage two share stage ones condenser to help cool the refrigerant before stage one evap exchanges heat from stage two lowering the heat load on stage one. Efficient. Balance.
We currently have a -80c freezer that is liquid cooled and it keeps having issues maintaining temperature. Does the second stage suction line temperature have a role in this? We see an identical model with a much higher temperature for this component than our freezer when it's struggling to maintain -80c.
Hi! Diagnosing a freezer based on a statement is very difficult. 1stage primary/only function is to cool the 2nd stage. The 2nd stage function is to cool the actual freezer space. We would start with the simple steps, verifying that the filter is clean, proper airflow around the freezer, and then look into the refrigeration system. Usually when the freezer is struggling to maintain temperature the second stage is probably in need of service. Initial steps would include, insulation integrity, refrigerant possibly low, if these initial steps did not correct the problem then the second stage would be completely serviced. Which would be to remove the compressor and flush the oil, replace the filter drier, then pressure test and recharge the system.
What is the ambient temperature? Maybe outside is just too hot.
Can i have a refrigerator circuit? Someone could help me ?
Great stuff. Thanks for sharing
How to start studying cascade refrigeration system
Would like to see the evaporator. Are there evaporator fans?
Hello,
In all of the ULT freezers we've had, the evaporator is actually copper pipes spread throughout the body of the freezer around the chamber. As such, there are no fans. Hope this helps!
thank you so much
Thank you
Excelente.
Great video but need to edit out the "uuummm" that I heard quite a bit. No hate ❤
It looks like a Type 1 appliance
Hindi me
does the ULT system needs a buffer tank
HI! The older units have an expansion tank, if this is what you are referring to as a buffer tank then yes.