Johnson Controls P545NCB-25 Oil Control

The Johnson Controls P545NCB-25 is a high-performance electronic lube oil control designed for refrigeration compressors featuring single-point differential pressure monitoring. Engineered by PENN Controls, this unit integrates a P400BD-1 differential pressure switch and a 120-second factory set time delay to protect mechanical components during low-pressure events. Operating on 120/240 VAC, it continuously evaluates net oil pressure, ensuring the compressor oil safety switch only triggers a lockout if the differential falls below 10 PSI ± 1.5 PSID for a sustained period. This model is optimized for non-corrosive refrigerants and features a manual reset to ensure a technician inspects the system before a restart. The inclusion of SPDT relay contacts allows for seamless liquid line solenoid integration and remote alarm signaling, while front-mount LEDs provide instant diagnostics of the lubrication system status. With simplified backwards compatibility, it serves as a reliable field replacement for legacy oil pressure failure switches in commercial HVACR applications.

• Enhanced Compressor Protection: Prevents catastrophic failure by monitoring net oil pressure and de-energizing the contactor if lubrication is insufficient.
• Reduced Short-Cycling: Features a selectable anti-short cycle timer (0 to 100 seconds) to protect the motor from frequent start/stop stress.
• Integrated Diagnostics: Front-facing LEDs show green for "on," yellow for "timing," and red for "lockout," facilitating rapid troubleshooting.
• Built-in Test Circuit: Enables technicians to verify electrical functionality and timing without needing external gauges or tools.
• System Coordination: Dedicated terminals for liquid line solenoid control help prevent refrigerant migration during low oil pressure shutdowns.

Is the P545NCB-25 compatible with ammonia systems?
No, this specific model is designed for use with non-corrosive refrigerants only. For ammonia applications, a stainless steel or corrosion-resistant pressure switch is required.

Can I adjust the 120-second time delay in the field?
The primary lube oil time delay is factory-set and cannot be field-adjusted to ensure compliance with compressor manufacturer specifications. However, the anti-short cycle delay can be configured using internal jumpers.

Does this unit come with the necessary wiring?
Yes, the P545NCB-25 typically includes the P400 switch and the required WHA-P400-125 wiring harness for immediate installation into the compressor oil pump port.

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.