Johnson Controls Pressure Switch Fan Cycling In 400PSI

The Johnson Controls P100AP-332C is a fan cycling pressure switch with an approximate 400 PSI rating.

Fan cycling control addresses a problem specific to air cooled condensers operating in cold weather. The condenser is sized to reject heat on a design summer day, and in cold ambient conditions it rejects heat far too effectively. Head pressure falls, and with it the pressure differential across the metering device.

That differential is what drives refrigerant through the expansion device. Too little, and the evaporator is starved regardless of how much refrigerant the system contains. The symptoms are poor cooling, low suction pressure, and on refrigeration systems a fixture that will not pull down, all occurring specifically in cold weather.

A fan cycling switch senses head pressure and cycles the condenser fan off when pressure falls below its setpoint, allowing head pressure to rise back to a workable level. On multi-fan condensers, staged switches cycle fans progressively.

The 400 PSI figure relates to the pressure range the control operates within, which suits higher pressure refrigerants.

Setpoints must suit the refrigerant in the system, since the pressure corresponding to a given condensing temperature differs substantially between refrigerants.

Applications include commercial refrigeration and air conditioning with air cooled condensers.

Brand

Johnson Controls

SKU

P100AP-332C

Category

Pressure Switches

Weight

0.2 lbs

Dimensions

4.20" x 1.50" x 1.20"

Price

$56.00

Availability

In stock

Rating

4.8 / 5.0