Johnson Controls P32AC-1 Pressure Switch

The Johnson Controls P32AC-1 is a robust sensitive differential pressure switch designed for precision air flow monitoring in commercial Building Automation Systems (BAS). Engineered for versatility, this adjustable pressure switch operates within a setpoint range of 0.15" Wc to 12" Wc, providing reliable performance for air proving in electric duct heaters and variable air volume (VAV) systems. The internal scale plate allows for simplified field calibration, ensuring setpoint accuracy without the need for external manometers during routine checks. Built with a durable Buna-N diaphragm and a NEMA 1 enclosure, it handles 1/2 horsepower loads at 120/240 Vac while maintaining high repeatability.

For veteran technicians, the SPDT contact action (Single Pole Double Throw) offers flexible wiring configurations for either opening or closing circuits upon pressure rise or fall. This makes it an essential component for clogged filter detection and frost monitoring on air conditioning coils. The included L-bracket facilitates mounting in various orientations, though vertical installation is recommended to maintain factory calibration. This HVAC differential pressure control is a standard-setting replacement for legacy pressure sensors, ensuring compatibility across a wide range of pneumatic and electrical HVACR infrastructures.

• Precise Field Adjustability: Features an integrated scale plate for rapid setpoint selection between 0.15 and 12 inches of water column.
• Versatile Application: Ideal for vacuum detection, positive gauge pressure monitoring, or differential pressure sensing in ductwork.
• Contractor-Grade Durability: Equipped with a dust-tight snap switch and metallic high-pressure connections to withstand demanding mechanical room environments.
• Flexible Compatibility: The 1/8" FNPT and 1/2" NPSM fittings allow for seamless integration with existing tubing and conduit hardware.

How do I wire the P32AC-1 for air flow proving?
For standard proof-of-flow applications with electric heaters, wire the common (Red) and normally open (Yellow) terminals. The circuit will close once the differential pressure rises above your setpoint, ensuring the heater only energizes when sufficient airflow is present.

Does mounting position affect the setpoint accuracy?
Yes. While this switch is factory-calibrated for vertical mounting, installing it horizontally with the high-pressure port facing down can increase the setpoint by approximately 0.07" Wc. Always recalibrate the switch in its final mounted position.

Can this unit be used for combustion air applications?
The P32AC-1 is primarily designed as an operating control for general HVAC air sensing. For specialized combustion air applications, refer to the specific P32 series technical bulletins for high-temperature or safety-limit requirements.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.