Ranco P30-3701 Oil Control

The Ranco P30-3701 is a commercial-grade lube oil protection control designed to prevent catastrophic compressor failure and bearing damage in pressure-lubricated refrigeration systems. Engineered with a built-in 90-second time delay, this mechanical oil pressure switch monitors the differential between the oil pump outlet and the crankcase pressure. If the effective oil pressure drops below the setpoint, the S30 time delay module initiates a countdown, allowing the system to stabilize during normal startup or momentary fluctuations. If pressure isn't recovered within the window, the manual reset circuit opens, safely shutting down the compressor.

Built for the rigors of field service, the P30-3701 oil control features a 36-inch capillary with 1/4" flare nuts, utilizing the Super Cap capillary protection system to resist vibration-induced fatigue. This unit is compatible with 120V or 240V AC pilot duty circuits and is a direct drop-in replacement for many Johnson Controls P28 and Penn P28AA-1C series switches. The adjustable pressure range of 8 to 60 PSI and ambient temperature compensation ensure reliable HVAC compressor protection across diverse operating environments.

Key Benefits

• Precise Differential Monitoring: Accurately tracks the pressure delta to ensure adequate lubrication before a hard shutdown occurs.
• Field-Replaceable Components: Features a replaceable S30-1200 time delay module and field-replaceable switch for simplified maintenance.
• Enhanced Durability: Equipped with a high-impact, non-conductive cover and captive cover screw to streamline installation.
• Integrated Alarm Circuit: Includes a standard alarm circuit to provide immediate notification of a low oil pressure trip.
• Broad Compatibility: Cross-references with major brands like Carrier, Danfoss, and Trane for versatile application in commercial refrigeration.

Common Questions

How do I wire the Ranco P30-3701 for 240V systems?
This control features universal terminal identification. You must select the appropriate 120V or 240V terminal for the bimetal heater based on your control circuit voltage to ensure the timing circuit functions correctly.

What is the purpose of the 90-second delay?
The delay prevents "nuisance trips" caused by temporary oil pressure drops during compressor start-up or during defrost cycles when refrigerant dilution might occur.

Can I use this with any refrigerant?
The P30 series is designed for use with all non-corrosive refrigerants commonly found in commercial HVACR applications.

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.