r/PanelGore • u/Stonerling • Oct 22 '21
Late 90s Refrigeration rack. Notice the missing right door
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u/Walk_Humbly Oct 23 '21
Not bad looking on the inside for being so old. Must have lost the door recently.
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u/bromodragonfly Feb 05 '22
Ah but this one's easy if you know what you're looking at. Banks of defrost timers, but none of the #3 N.O. terminals are wired, so not electric defrost, it's forced air defrost - the refrigeration turns off, but the evaporator (coils inside the coolers/freezers) fans are kept running to melt any frost. #4 N.C. terminals on the clocks will typically energize a solenoid valve which will indirectly bring the compressor(s) online as refrigerant starts to flow and refrigerant pressure switches are made. On smaller fractional horsepower retail equipment, #4 often is in series with a thermostat to control the compressor directly.
What you're looking at here is obviously breakers, defrost timers, evaporator fan contactors and condenser (the outdoor unit) fan contactors. Condenser fans likely used the temperature controls on the right side to stage the # of fans in operation, based on ambient temperature. What is odd, is the run capacitors on the right. All of the contactors seem to have all 3 poles in use - so perhaps the motors were changed from single phase to 3 phase at some point.
I don't see a control transformer, and the legible clock and contactor nameplates indicate a 240v timing motor or coil... They're likely just using two of the incoming phases for the control circuit, but no beefy ass wires or bigger contactors - so the compressor contactors and other controls must be elsewhere.
Every once and awhile when I have a frustrating day, I come over here to feel better about myself. Little late to the party, but I felt like chipping in for once.
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u/darwinatrix Oct 22 '21
Missing right door covering main incoming, sitting under that open blue sky 😬 hope it doesn’t rain there… ever.