Johnson Controls Pressure Switch Fan Cycling In 275PSI

The Johnson Controls P100AP-354C is a fan cycling pressure switch with an approximate 275 PSI rating.

The distinction between this and higher pressure fan cycling controls is the pressure range at which it operates, and that range must match the refrigerant in the system.

This is a point that causes real confusion in the field. A fan cycling control operates on pressure, but what actually matters is the condensing temperature that pressure corresponds to. Because each refrigerant has its own pressure-temperature relationship, the same pressure represents quite different condensing temperatures in different systems. A control set correctly for one refrigerant will cycle fans at the wrong condensing temperature in a system running another.

For that reason, fan cycling controls are selected and set with reference to the pressure-temperature chart for the specific refrigerant, targeting a condensing temperature that maintains adequate pressure differential across the metering device without running head pressure unnecessarily high.

Setting them too high wastes energy through elevated head pressure and reduced compressor efficiency; too low leaves the metering device starved in cold weather.

The 275 PSI range suits refrigerants operating at lower condensing pressures.

Applications include commercial refrigeration and air conditioning systems with air cooled condensers operating in variable ambient conditions.

Brand

Johnson Controls

SKU

P100AP-354C

Category

Pressure Switches

Weight

0.2 lbs

Dimensions

4.20" x 1.50" x 1.20"

Price

$43.00

Availability

In stock

Rating

0 / 5.0