P74BA-1C Johnson Controls Pressure Control

Overview

The Johnson Controls P74BA-1C is an adjustable electromechanical differential pressure control designed to sense pressure differences between two points in HVAC and industrial systems. It measures the difference in pressure exerted upon its two sensing elements and operates a single-pole single-throw (SPST) switch that opens on a decrease in pressure difference, providing a reliable control mechanism for building automation and air-side monitoring applications.

Features

• Incorporates a field-proven Pennswitch mechanism with completely enclosed contacts.
• Pressure differential setting is easily adjusted via an external wheel without removing the cover.
• Calibrated scale provides highly visible setpoint indication.
• Equipped with heavy-duty pressure elements engineered to withstand high overrun pressures.
• Supplied with a universal mounting bracket for flexible installation options.

Specifications

• Operating Pressure Range: 8 to 70 PSIG
• Differential Pressure Range: 8 to 30 PSI (adjustable)
• Contact Type: SPST (opens on decrease in pressure difference)
• Switch Rating: 20 A at 120 VAC, 18.7 A at 208 VAC, 17 A at 240 VAC (1 Phase AC Full Load)
• Maximum Overpressure: 180 psig
• Process Connection: 36-inch copper capillary tubes with 1/4-inch flare nuts
• Bellows Material: Stainless steel

Applications

• Designed for motor actuator positioning and refrigeration compressors.
• Used to prove pump operation and monitor flow conditions in heating or cooling systems.
• Suitable for detecting pressure drops across water chillers and water-cooled condensers.
• Frequently applied in air handlers, dampers, fans, and process control loops.