Johnson Controls P145NCB-82 Control

The Johnson Controls P145NCB-82 is a professional-grade lube oil pressure cutout control engineered for precision protection of pressure-lubricated refrigeration compressors. Designed as a direct P145NCA-82 replacement, this electromechanical safety switch monitors the net oil pressure—the critical difference between oil pump discharge and crankcase pressure—to prevent catastrophic mechanical failure. It features a factory-calibrated 6.5 PSI fixed differential and an ambient-compensated 45-second time delay, allowing sufficient pressure build-up during start-up while eliminating nuisance trips in commercial HVACR systems.

For contractors servicing Carlyle compressors or similar semi-hermetic units, the P145NCB-82 includes an integrated alarm circuit and is the functional equivalent to the P45NCB-25. This control is built with a rugged NEMA 1 steel enclosure and utilizes a 1/4" male flare pressure connection for seamless integration with standard refrigerant hoses or SEC99 UltraCap capillary tubes. The manual reset mechanism ensures that a technician must inspect the system after a low-pressure event, providing a vital layer of operational security for industrial cooling applications.

Key Benefits for HVACR Technicians

• Enhanced Compressor Safety: Provides dependable low pressure cutout to protect internal bearings and high-value mechanical components.
• Reliable Time Delay: The 45-second thermal expansion relay is compensated for ambient temperature variations, ensuring consistent timing in mechanical rooms.
• High Pressure Durability: Rated for a 425 PSIG maximum bellows pressure, making it suitable for a wide range of non-corrosive refrigerants.
• Versatile Power Compatibility: Supports dual-voltage 120/240 VAC wiring for simplified field installation across various equipment platforms.
• OEM-Quality Performance: Maintains the exact factory settings required by compressor manufacturers to prevent over-adjustment and unauthorized tampering.

Common Questions

Is the P145NCB-82 compatible with my Carlyle compressor?
Yes, this model is specifically designed for Carlyle and other pressure-lubricated compressors requiring a 6.5 PSI setpoint and 45-second delay. It effectively replaces the P145NCA-82 and P45NCB-25 models with the added benefit of an alarm circuit.

Can I use this control on a 208V system?
While the unit is rated for 120/240 VAC, for 208V applications, it is standard practice to use one leg of the 208V circuit and a neutral to power the 120V heater or use a step-down transformer to ensure consistent timing and relay operation.

Does this unit come with mounting hardware?
The P145NCB-82 is typically supplied as the control only. If your installation requires an angle bracket, you should utilize the BKT38A-600 or a universal mounting plate to secure the NEMA 1 enclosure.

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.