I am still learning about the controls on walk in freezers and coolers. I'm servicing one that is very old.
the evap sometimes freezes. I have been in my school books trying to understand the different types of controls.
I see how the pump down cycle works - shutting down the LL solenoid - pressure drops and contactor opens
via the low pressure switch. This unit has a defrost clock and a low pressure switch. the low pressure switch
has been by-passed. I don't have any info on the unit itself, It is 208/230 thee phase, single evap and condenser
the temp has been fluctuating between 20 & 30 deg, the label says 502 refrigerant. Sight glass is pretty clear. I'm just
not 100 percent sure what type of refrigerant is in it. I've been reading posts and I understand that if the door doesn't
seal properly, it can effect the temp. This one may have multiple problems. I have set 4 stops on the clock. the heaters
are working - I checked today. They get hot during defrost. Is it standard procedure to have a defrost
clock in conjunction with a LL solenoid > pump down circuit? I ohmed the contacts on the low pressure switch and
they do open and close when I adjust the cut out and cut in setpoints. but i'm not sure what to set it at, if I were to wire it back in.
Oh well i'm just trying to get some feedback. The defrost clock door will not shut and it is exposed to the weather. I should take some
pics on my new phone (Galaxy S4 Active) and repost tomorrow. this is quite a sight to see. When I say old, rusty and beat up - I mean
every word of it. thanks and sorry I don't have any model #'s tonight.