No head pressure control. This really isnt one of the most difficult pieces of equipment at all. I just wanted to make sure i was doing everything correct before I go back and charge. Its only about 2 years old if that, and im already replacing a comp. Not sure what tech. did before me. Old comp. LRA amped. Could have been coincidence but i doubt it. Im pretty sure it was a charging issue the first time.
Funny but they keep dirt in this cooler for research purposes. Yes unit has reciever, rooftop condnser, yes it is a pump down system.
Print out the document that I linked to earlier in this thread.
Read it and follow the instructions.
You will KNOW that the unit is charged properly.
If you want to get into WHY the compressor has failed in such a short time, you'll need to give us a full set of system operating conditions once you've got it back online
No head pressure control. This really isnt one of the most difficult pieces of equipment at all. I just wanted to make sure i was doing everything correct before I go back and charge. Its only about 2 years old if that, and im already replacing a comp. Not sure what tech. did before me. Old comp. LRA amped. Could have been coincidence but i doubt it. Im pretty sure it was a charging issue the first time.
A lot of times, that headmaster valve is stuck back in the back and isn't easy to see on a first inspection.
I don't know California's weather, but if your ambient drops much below 50F or so, you'll definitely need some sort of low ambient control to maintain a minimum liquid pressure.
We protect it by keeping it cool and ensuring that no liquid returns, I'm just saying with a reefer system charging it by checking compressor sh is a poor practice. I'm not saying it shouldn't be checked but sh should be checked and set at the evap. If its set 10* at evap but running 45* at compressor then there needs to be secondary means of cooling the compressor.
10-4, I agree. The original post was for some explanation on charging or rules of thumb. (not sure how to repost with my reply) So I gave a few. This not being a diy site, Didn't want to give to too much info. Just enough so anyone in the trade could find a few key points helpful. If we want to go crazy...I want pressures, sh, sc, amp draw, sight glass, were going see this box satisfy and make sure she pumps down. In the mean time if this isn't our account were checking the other equipment and working up a maintenance contract. Who was the last company out here?
Copeland recommends a minimum 20 to 40 degrees compressor superheat. Within this range you should be able to get the right evap SH. Compressor SH always trumps evap SH. Is this 59 degrees the temp you want or the temp you are getting before topping the charge off?
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Originally Posted by Ken11
