P70NA-1C Johnson Controls Pressure Control

Overview

The Johnson Controls P70NA-1C is a dual-pressure electromechanical control designed primarily for commercial refrigeration and air conditioning applications. It provides combined high- and low-pressure monitoring in a single device to directly regulate compressor operations. By responding to real-time system pressure changes on both the high and low sides, it ensures optimal equipment protection and system integrity.

Features

• All-Steel Construction: Equipped with a durable all-steel case and cover that offers rugged, long-lasting protection for internal electrical and mechanical components.
• Dual Manual Reset Lockout: Provides a trip-free manual reset lockout mechanism for both high-pressure and low-pressure sides, preventing unmonitored equipment from automatically restarting until conditions return to safe operational levels.
• Sight-Set Calibration: Features a visible, calibrated pressure scale on the NEMA 1 enclosure, enabling straightforward adjustments across the range without removing the cover.
• Dual Copper Capillaries: Includes two 36-inch copper capillary tubes equipped with 1/4-inch flare nuts for secure connection to system lines.
• Premium Sensing Technology: Utilizes reliable bellows sensing elements engineered for long-term operational stability.

Specifications

• Switch Action: Single-Pole Single-Throw (SPST)
• Low-Pressure Range: 20 in. Hg to 100 psi (-68 to 690 kPa)
• Low-Pressure Differential: Fixed (manual reset lockout)
• High-Pressure Range: 100 to 500 psi (690 to 3,447 kPa)
• High-Pressure Differential: Fixed (manual reset lockout)
• Pressure Connection: 36 in. Capillary with 1/4 in. Female Flare Nut
• Enclosure Rating: NEMA 1 standard
• Media Compatibility: Non-corrosive refrigerants

Applications

• Commercial Refrigeration Systems: Monitors low-side and high-side compressor pressure to maintain safe operating parameters.
• Air Conditioning Systems: Controls and protects compressors against extreme pressure fluctuations in commercial environmental control setups.
• HVAC Building Automation: Serves as a critical safety device within building HVAC controls to prevent equipment damage due to refrigerant loss or line blockages.