Has anybody heard of or used a latching relay? I’ve been working on an older tired York condenser with a semi hermetic compressor. The oil pressure switch was bypassed by others. After installing the new oil pressure switch we kept having nuisance trips. I found the LL solenoid also wired open and the unit running unloaded. The solenoid was passing (noticeably leaking oil too) so the the LPS would make and the unit would constantly cycle on and off to initiate pump down. I replaced the solenoid, dryers, and re charged with R22. RS44B had been previously retrofitted I just wanted to return the unit to factory specs. Though the unit would still bleed by in the suction so I’m thinking the compressor valves are passing now. So now the unit will initiate pump down even after the call, just not as often. I installed an adjustment low pressure control as to increase my differential and have less recycles on the pump down. It worked, but now my oil switch was tripping randomly. What I found was that the unit would recycle the pump down and open the LPS, immediately after I would see a call for Y1. Though because the compressor controller just cycled on for the recycle it would hold out on the y1 call long enough for the oil monitor to trip because the Y1 call has been sitting on the oil switch and hadn’t seen a pressure differential. My fix was to run the control circuit for the pump down to a delay on make timer. This held out the unit long enough to reset the compressor controller and also not have the call sitting on the oil switch. Units running but I read about a latching relay that is designed for this exact purpose.

Posted by Krustinitus at 2021-05-11 23:44:12 UTC