Late to the party but thank you for what you are doing!! I just started listening to the podcast and watching your videos and it is amazing! One day at a time and keeping up with my learning. Thank you sir!
It is never too late to learn. Thank you for investing in yourself and your refrigeration knowledge. You can find more great content here linktr.ee/refrigerationmentor
Brand new service tech to the trade (almost a year into it and thrown to the wolves) Just so happens I got the email this morning for this video. And yesterday I had a compressor fail. Broke it down and found that it had a bad valve plate. I will definitely be watching this video again while I trouble shoot the issue. A piece of the valve plate broke off where the pistons push through. I’m still learning the correct terminology so I apologize.
I just replaced an AC and heater in a 22-year-old home. After 2 days the compressor stopped working - just ambient air from the vents. The thermostat actually alerted me to this with an error message. The company came out quickly to check - the compressor was very hot - they cooled with water (I'll assume to reset a thermal switch) - it ran for about 5 minutes then shut off - the fan still working but no cool air. The unit will be replaced tomorrow but I wonder if a 4-ton AC unit (Had a 5 ton for 22 years) will need to work harder than a 5 ton, thus running longer before the home cools down to the thermostat set point - and if it runs longer, will it heat up more and possibly this happen again? Vent calculations were done, a 4-ton was called for, so I can't really question this, but I think strange a brand-new unit would fail at the compressor. Are there things I can check weekly after the new unit is installed to be sure it's not going to fail when it's 95+ outside. I will monitor the temp at the exit of the compressor (just outside the AC unit) and it should be very cold. I will take reading with an IR thermometer and note these. One other thought - if the duty cycle of the compressor was 70/30 (on/off) I can see it might not have time to cool down before the compressor starts again - thus heating up an already hot compressor. Any way to estimate how long it should take a 3400sq/ft home to cool from 78 to 73? is there a rule of thumb in this area? Yes, window efficiency and air leaks in the home will matter, but just in general.. should it cool 2 degrees per hour? more / less? and if the home heats up from 3pm-8pm and the AC can't keep up, so it's on all the time, does this mean I need a larger AC unit (more tonnage?) Thanks for any input.
there are some rule of thumbs but not real standards alway go into the operation envelop or performance chart to make sure you stay inside. Low temp compressors will run at a higher compression ratio
Uh-oh... this video is not for the uneducated (me). Just an old person looking for a way to fix my chest freezer i use as a frig (it's only a year and a half old; overheating terribly). Thank you.
@@RefrigerationMentor thank you very much for your reply-- my guess is dirty coils (have a Lab who tracks in a lot of dirt) but can't get to them. Appears to require turning over and access underneath. Tried side panel, no coils there. No access at back or other side, so i guess underneath. Frigidaire 7 cubic ft chest freezer. (Customer svc closed thru weekend.) Thank you!
Yes, everything you said is really important, but it is very important to run the system at a superheat value suitable for the design. While a high superheat value may cause overheating in the compressor, a low superheat value may cause liquid refrigerant to reach the compressor. Super heat control must be performed, especially in systems with long distances between the evaporator and condenser or in systems where the suction pipe has to be replaced (there may be a need to move the outdoor unit).
@@RefrigerationMentor Oh I already figured this out. It's because when you add/subtract the same number to the top and bottom of a fraction, you can't just cancel them out like you can if you multiply top and bottom by the same number. So 1/2 is .5, but if you add 14.7 to both top and bottom, you get 15.7/16.7, which is most certainly not .5. But if you multiplied 1/2 by 14.7, both the top and bottom, you get 14.7/29.4, which is still .5, so you can cancel it out. DIfference between absolute and gauge is addition, not multiplication, so you can't cancel it out, which is why that extra 15 or 14.7 is important for compression ratio.
What’s the high end of superheat that’s acceptable to Copeland If my memory serves me you said 20-40 is acceptable. 40 being the max as long as the discharge is not above 225 deg Please if you see this comment let me know so I know I am telling the junior techs right Thanks
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Late to the party but thank you for what you are doing!! I just started listening to the podcast and watching your videos and it is amazing! One day at a time and keeping up with my learning. Thank you sir!
It is never too late to learn. Thank you for investing in yourself and your refrigeration knowledge. You can find more great content here linktr.ee/refrigerationmentor
Thank you very much. I really appreciate what you have done and continue to do for our industry!
Our pleasure!
Nice video
Brand new service tech to the trade (almost a year into it and thrown to the wolves) Just so happens I got the email this morning for this video. And yesterday I had a compressor fail. Broke it down and found that it had a bad valve plate. I will definitely be watching this video again while I trouble shoot the issue. A piece of the valve plate broke off where the pistons push through. I’m still learning the correct terminology so I apologize.
It’s so good to hear that you are taking the compressors apart and inspecting them.
Thank you for share with us your knowledge. A follower from Venezuela. Grettings
My pleasure Gustavo!
I just replaced an AC and heater in a 22-year-old home. After 2 days the compressor stopped working - just ambient air from the vents. The thermostat actually alerted me to this with an error message. The company came out quickly to check - the compressor was very hot - they cooled with water (I'll assume to reset a thermal switch) - it ran for about 5 minutes then shut off - the fan still working but no cool air. The unit will be replaced tomorrow but I wonder if a 4-ton AC unit (Had a 5 ton for 22 years) will need to work harder than a 5 ton, thus running longer before the home cools down to the thermostat set point - and if it runs longer, will it heat up more and possibly this happen again? Vent calculations were done, a 4-ton was called for, so I can't really question this, but I think strange a brand-new unit would fail at the compressor. Are there things I can check weekly after the new unit is installed to be sure it's not going to fail when it's 95+ outside. I will monitor the temp at the exit of the compressor (just outside the AC unit) and it should be very cold. I will take reading with an IR thermometer and note these. One other thought - if the duty cycle of the compressor was 70/30 (on/off) I can see it might not have time to cool down before the compressor starts again - thus heating up an already hot compressor. Any way to estimate how long it should take a 3400sq/ft home to cool from 78 to 73? is there a rule of thumb in this area? Yes, window efficiency and air leaks in the home will matter, but just in general.. should it cool 2 degrees per hour? more / less? and if the home heats up from 3pm-8pm and the AC can't keep up, so it's on all the time, does this mean I need a larger AC unit (more tonnage?) Thanks for any input.
Thanks a million ! You made it super easy and understandable
What will be the effect on discharge line temperature if we put the compressor in the path of condenser airflow?
It will reduce the temperature of the discharge as the hottest part of heat of compression happens inside the compressor itself. Great question!
Thank you for this Update.
What is the formula to convert from °F to K?
How I was shown was divide °F by 1.8 so 20F/1.8 = 11K
@@RefrigerationMentor Thank you very much! waiting more of your update
Another great video, keep up the good work.
Thank you
What is the standard compression ratio
there are some rule of thumbs but not real standards alway go into the operation envelop or performance chart to make sure you stay inside. Low temp compressors will run at a higher compression ratio
Uh-oh... this video is not for the uneducated (me). Just an old person looking for a way to fix my chest freezer i use as a frig (it's only a year and a half old; overheating terribly). Thank you.
@@2Hearts3 well it could be low on charge, plugged capillary tube or dirty condenser.
@@RefrigerationMentor thank you very much for your reply-- my guess is dirty coils (have a Lab who tracks in a lot of dirt) but can't get to them. Appears to require turning over and access underneath. Tried side panel, no coils there. No access at back or other side, so i guess underneath. Frigidaire 7 cubic ft chest freezer. (Customer svc closed thru weekend.) Thank you!
Yes thank you so much loving this better than my lecturer
You're very welcome!
Yes, everything you said is really important, but it is very important to run the system at a superheat value suitable for the design. While a high superheat value may cause overheating in the compressor, a low superheat value may cause liquid refrigerant to reach the compressor. Super heat control must be performed, especially in systems with long distances between the evaporator and condenser or in systems where the suction pipe has to be replaced (there may be a need to move the outdoor unit).
All valid points. Thanks for sharing.
Really valuable information ,
Thanks
We are glad you enjoyed this video.
Great Trevor 👍
Thanks 👍
What’s the point of converting to absolute from gauge? My high school maths is telling me this cannot affect the ratio when added to both sides.
That’s a great question. I will look into that.
@@RefrigerationMentor Oh I already figured this out. It's because when you add/subtract the same number to the top and bottom of a fraction, you can't just cancel them out like you can if you multiply top and bottom by the same number. So 1/2 is .5, but if you add 14.7 to both top and bottom, you get 15.7/16.7, which is most certainly not .5. But if you multiplied 1/2 by 14.7, both the top and bottom, you get 14.7/29.4, which is still .5, so you can cancel it out. DIfference between absolute and gauge is addition, not multiplication, so you can't cancel it out, which is why that extra 15 or 14.7 is important for compression ratio.
Thanks
Your Welcome!
Provide compressor guide
offers.refrigerationmentor.com/free-guide
Dommage je comprends pas l'anglais
Yeah it’s good.
Thx sir
Your welcome
What’s the high end of superheat that’s acceptable to Copeland
If my memory serves me you said 20-40 is acceptable.
40 being the max as long as the discharge is not above 225 deg
Please if you see this comment let me know so I know I am telling the junior techs right
Thanks
Yes if you can maintain a 20F (11K) superheat at the compressor and the discharge below 225F (107C) you should be good.
Hi, if I convert °F to °C, will it still be °C/1.8?
Good
Thank you
Good
Thank you! More great content here linktr.ee/refrigerationmentor