Johnson Controls P72LB-1 Pressure Control

The Johnson Controls P72LB-1 is a robust dual pressure control designed for heavy-duty commercial refrigeration and HVAC applications. Featuring a DPST (Double-Pole Single-Throw) switch mechanism, this all-range pressure switch provides direct individual control of single-phase motors up to 3 hp and three-phase motors up to 5 hp, eliminating the need for separate contactors in many setups. The low-pressure side handles a range of 20" Wc to 100 psi with an adjustable 6 to 50 psi differential, while the high-pressure side operates between 100 and 425 psi with a fixed differential of 55 to 65 psi depending on system load. Built with a rugged steel case, the P72LB-1 is compatible with R-22, R-134A, R-404A, and other non-corrosive refrigerants. Field installation is streamlined by the 36-inch capillary with 1/4" flare nut and the included universal mounting bracket. For technicians requiring precision, the "Sight-Set" calibrated scale allows for visible pressure adjustments without removing the cover, ensuring accurate condenser fan cycling and compressor protection.

• DPST Switch Logic: Provides direct-drive capability for high-amp motors, reducing component count and installation complexity.
• Multi-Refrigerant Compatibility: Designed as an "All Range" control compatible with R-12, R-22, R-134A, R-500, and R-502.
• Rugged Construction: Features an all-steel case and cover to withstand vibration and harsh mechanical room environments.
• Visible Calibration: Integrated adjustment knobs and "Sight-Set" scales allow for rapid setpoint verification and field tuning.

How do I adjust the high-pressure cutout on the P72LB-1?
The high-pressure cutout is set using the range screw located at the top of the unit; however, note that the high-side differential is fixed and cannot be adjusted independently.

Is this control suitable for R-410A systems?
The high-pressure range of up to 425 psi is typically sufficient for many R-410A applications, but always verify your specific system's discharge pressure requirements against the 525 psi maximum overpressure rating.

What is the difference between the P72 and P70 series?
The primary difference is the switch action; the P72 series utilizes DPST contacts for load-carrying capacity, whereas the P70 series often uses SPST or SPDT switches for pilot duty or smaller loads.

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.