Bryant 551B, 558F, 551A manual Perfect Humidity Dehumidification Option, CONTROLS cont

CONTROLS (cont)

As the refrigerant leaves the evaporator, the refrigerant passes a subcooler control low-pressure switch (S-LPS1 for circuit 1 or S-LPS2 for circuit 2) in the suction line. This low-pressure switch will deactivate the Perfect Humidity™ package when the suction pressure reaches 60 psig. The subcooler control low- pressure switch is an added safety device to protect against evaporator coil freeze-up during low ambient operation. The subcooler control low-pressure will only deactivate the 3-way liquid line solenoid valve in the Perfect Humidity circuit. The compressors will continue to run as long as there is a call for cooling, regardless of the position of the subcooler control low- pressure switch. The 3-way solenoid valve and the Perfect Humidity package will be reactivated only when the call for cool- ing has been satisfied, the subcooler control low-pressure switch has closed above 80 psig, and a new call for cooling exists. The crankcase heaters on the scroll compressors provide additional protection for the compressors due to the additional refrigerant charge in the subcooler.

When the thermidistat is satisfied, the relay internal switch opens, cutting power to and deenergizing the LLSVs. The refrigerant is routed back through the evaporators and the subcooler coils are removed from the refrigerant loops. When the thermostat is satisfied, C1 and C2 are deenergized and the compressors, IFM, and OFMs shut off. If the thermostat fan selector switch is in the ON position, the IFM will run continuously.

Perfect Humidity™ Dehumidification Option

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