Johnson Controls P74HA-14 Pressure Control

The Johnson Controls P74HA-14 is a professional-grade differential pressure control designed for heavy-duty HVACR applications, including chiller proof-of-flow and compressor lube oil pressure sensing. This rugged controller features a specialized switch action where the main contacts close on differential increase while the separate auxiliary contacts open, making it ideal for simultaneous equipment operation and status signaling. Built with a robust 8 to 70 psi range, this unit integrates two opposing brass bellows elements to accurately monitor the pressure drop across two distinct points in a system.

For technicians working with non-corrosive refrigerants or water-circulating systems, the P74HA-14 provides a reliable SPDT snap-acting switch mechanism. The adjustable differential pressure allows for precise field calibration via an internally located hexagonal nut, while the primary setpoint is easily managed through a top-mounted adjusting disk and calibrated scale. Whether you are managing flow across a water-cooled condenser or protecting a refrigeration rack, this Penn pressure switch ensures high contact force and no contact bounce for long-term operational stability.

• Versatile Application: Effective as either an operating control or limit control for liquid, air, or oil pressure monitoring.
• Dual-Signal Logic: Features 4-terminal wiring that allows the main circuit to engage while an auxiliary alarm circuit disengages on pressure rise.
• Enhanced Durability: Low-profile pressure elements are engineered to withstand high overrun pressures often encountered during system startup or transit.
• Precise Calibration: Large, legible scale and a "trip-free" design ensure repeatable HVAC pressure regulation in demanding environments.

What is the standard connection type for the P74HA-14?
This model typically utilizes a Style 13 connector, which includes 36 inches of capillary tubing with a 1/4-inch flare nut, though 1/4-inch male flare (Style 5) and FNPT (Style 15) variations exist for specific ammonia or high-pressure gas applications.

Can the P74HA-14 be used as a safety cutout?
While often used for proof-of-flow, it is designed as an operating control. For safety-critical applications, it is recommended to pair this with a dedicated manual-reset cutout like the P28 series for comprehensive compressor protection.

Is this control compatible with ammonia systems?
Standard P74 models are for non-corrosive refrigerants. If your application involves ammonia, verify that the unit features the stainless steel bellows and appropriate NPT connection required for corrosive media.

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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.