The Johnson Controls P29NC-2C Pressure Control W/TIME DELAY; 20″/100# 60 SEC.TIME DELAY 1/4″MALE FLARE
The P29 combines a pressure sensing mechanism with a time delay. A drop in pressure energizes the time delay relay which opens a contact after a predetermined time period. There are two principal applications for this control:
- Chiller Low Temperature Cutout: Pressure element is connected to the suction side of a chiller refrigeration system and the time delay relay is wired to the compressor control circuit. Prolonged low suction pressure, such as pressure caused by a low temperature condition, will cause the control to shut down the refrigeration compressor.
- Industrial Equipment, Oil Pressure Lubrication Cutout: On any electrically driven machine with a forced oil system, the pressure element is connected to the lube oil system and the time delay relay is wired in the control circuit. The control time delay allows oil pressure to build up to normal on start-up or recover from temporary fluctuations. A sustained loss of oil pressure will cause the control to shut down the machine.