P29NC-3C Johnson Controls Pressure Control

Overview

The Johnson Controls P29NC-3C is a low pressure cutout control with a built-in time delay relay designed for HVAC and refrigeration systems. It combines a pressure sensing mechanism with a 60-second time delay to prevent nuisance shutdowns due to momentary fluctuations in system pressures. A sustained drop in pressure energizes the time delay relay and opens a contact, requiring a manual reset to restart the equipment.

Features

• Direct reading scale indication for clear pressure setting visibility
• Dust-protected snap-action switch to maintain internal cleanliness and operational reliability
• Trip-free manual reset mechanism requiring human intervention after a low-pressure lockout
• Built-in 60-second time delay relay to minimize unnecessary equipment cycling

Specifications

• Pressure Range: 20 in. Hg vacuum to 100 PSIG
• Time Delay: 60 seconds
• Contact Form: SPST
• Capillary Length: 36-inch copper capillary tube with 1/4-inch flare nut
• Differential Pressure: 2.2 +/- 1.5 PSI
• Control Voltage: 120/240 VAC
• Maximum Working Pressure: 250 PSIG
• Overpressure Rating: 325 PSIG

Applications

• Chiller low-temperature protection by monitoring the suction side of refrigeration systems
• Industrial equipment lubrication monitoring to protect electrically driven machines with forced oil systems
• Low suction pressure safety cutout for commercial HVAC and refrigeration compressors