Johnson Controls P72MA-1 Pressure Control

The Johnson Controls P72MA-1 is a robust DPST Dual Pressure Control designed for heavy-duty commercial refrigeration and HVAC systems. This Two Pole pressure switch provides simultaneous control of high-side and low-side pressures, making it an essential component for protecting compressors against low suction or excessive discharge pressures. The low-pressure side features an adjustable range of 20" Wc to 100 psi with a field-settable differential of 6 to 50 psi. For critical safety, the high-pressure side operates between 100 to 425 psi and incorporates a manual reset lockout, ensuring the system remains offline until a technician can diagnose the high-head condition. Engineered as an "All Range" pressure control, it is fully compatible with R-12, R-22, R-134A, R-500, and R-502. The unit includes a 36-inch capillary with a 1/4-inch flare nut, a mounting bracket, and an adjustment knob for precise field calibration.

Key Benefits for Contractors

• DPST Switching: The Double Pole Single Throw configuration allows for the direct control of three-phase loads through a contactor or the simultaneous switching of two separate circuits.
• Manual Reset Safety: High-pressure lockout prevents short-cycling under fault conditions, protecting the compressor from mechanical failure.
• Versatile Refrigerant Application: Designed for use with all standard non-corrosive refrigerants, streamlining truck stock requirements.
• Installation Ready: Comes complete with a universal mounting bracket and adjustment knob for immediate field commissioning.

Common Questions

What is the difference between the P72MA-1 and standard P70 controls?
The P72 series features DPST contacts, whereas the P70 series typically utilizes SPST or SPDT. This allows the P72MA-1 to break both lines of a 208/240V circuit or control separate auxiliary components simultaneously.

How do I reset the high-pressure lockout?
The high-pressure side requires a manual intervention. Once the head pressure drops approximately 35-50 psi below the cutout point, the reset button on the top of the housing can be depressed to restore operation.

Can this be used on R-410A systems?
The P72MA-1 has a maximum high-pressure cutout of 425 psi. Since R-410A systems frequently operate at higher discharge pressures, this control is primarily intended for medium and low-pressure refrigerants like R-134A or R-22 legacy systems.

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.