Allows air conditioning to be used in cold weather (Examples: Computer Room Cooling, Dance Clubs Etc.)
Supco Tee Connection (SF9601 or SF9602),
Crank Case Heater (CH101, CH102, CH103 etc or for a 1 ton mini-split use a CH197.) and a Mini-Pressure Fan cycle switch (MPF-7008 or MPF-7009)
The MPF-7008 Cuts In @ 225psig and Cuts Out @ 150psig, and the MPF-7009 Cuts In @ 275psig and Cuts Out @ 190psig.
Wire the crankcase heater into the permanent hot side of the contactor. The Tee Connection gets placed on the liquid line right on the shrader valve and the Pressure Switch gets placed on the tee connection. Then the pressure switch is wired into the fan circuit to delay the fan from coming on until the desired psig is reached.
Note: The customer can wire a t-stat in line with the pressure switch to cut it out in warmer weather.