P70LB-6C Johnson Controls Pressure Control

Overview

The Johnson Controls P70LB-6C is a high-performance dual pressure control designed primarily for combination high- and low-pressure applications in commercial refrigeration and air conditioning systems. This dual-function control responds directly to system pressure shifts on both the high and low sides, enabling single-device control over the compressor to optimize system efficiency and safety. It features a single-pole single-throw (SPST) switch configuration that opens the circuit when pressure exceeds or drops below the defined thresholds, protecting vital HVAC/R equipment from adverse operational conditions.

Features

• Sight-Set Calibrated Adjustment: Features a visible calibrated pressure scale on the enclosure, enabling full and easy adjustability through the pressure range without needing to remove the cover.
• Precision Differential Option: Built with a MICRO-SET differential mechanism that allows for ultra-fine adjustments and precision pressure control on low-pressure systems.
• Robust Enclosure: Contained within a rugged, all-steel case and cover designed to provide long-lasting protection for internal components in demanding commercial environments.
• High-Side Lockout Safety: Equipped with an independent high-pressure safety cutout mechanism to prevent automatic resetting under dangerous high-pressure conditions.
• Anti-Bounce Contacts: Engineered with a long-life contact structure featuring no bounce on make to ensure reliable electrical connection and extended runtime.

Specifications

• Switch Action: Single-Pole Single-Throw (SPST); opens on low pressure drop or high pressure rise.
• Low Pressure Range: 12 in. Hg to 80 psig (-41 to 552 kPa)
• Low Pressure Differential: Adjustable from a minimum of 5 psi (34 kPa) to a maximum of 35 psi (241)
• High Pressure Range: 100 to 500 psig (690 to 3447 kPa)
• High Pressure Differential: Non-adjustable, fixed at approximately 65 psi (448 kPa)
• Pressure Connection: 36-inch capillary line equipped with a 1/4-inch flare nut
• Adjuster Option: Included adjustment knob for external setting changes
• Compatibility: Designed for use with common non-corrosive refrigerants (such as R-12, R-22, R-134a, R-500, and R-502)
• Enclosure Rating: Standard NEMA 1 Type enclosure

Applications

• Commercial Refrigeration: Used as a combination high-side and low-side operating control for commercial display cases, walk-in coolers, and freezing units.
• Air Conditioning Systems: Implemented within commercial HVAC systems to regulate compressor function based on refrigerant loop pressure fluctuations.
• Safety Cutout Control: Functions as a critical safety switch to shut down compressors during low-charge conditions (loss of pressure) or restricted high-side flow (overpressure).