Johnson Controls P47AA-1 Pressure Control

The Johnson Controls P47AA-1 is a commercial-grade steam pressure limit control designed for high-limit cutout or operating control in low-pressure steam heating systems. This SPST pressure switch is engineered to open the circuit on a pressure rise, featuring an automatic reset mechanism that restores operation once the system pressure drops below the differential setting. With a versatile operating range of 0 to 15 psig and an adjustable differential of 2 to 8 psi, this unit provides precise setpoint management for contractors managing boiler safety protocols.

Built with a durable brass bellows sensing element, the P47AA-1 is compatible with steam, water, air, and non-combustible gases. Its "sight-set" calibrated scales allow for rapid field adjustments of both cut-in and cutout points without the need for external gauges during the initial setup. This limit control supports multiple electrical ratings, including 120/208/240/277 VAC, making it a standard replacement for low-pressure boiler systems and industrial Vulcan steamers. For optimal performance, always install the control on a siphon (pigtail) to prevent live steam from impacting the internal components.

• Enhanced Safety: High-force SPST contacts provide reliable open on rise action to prevent overpressure conditions.
• Field Versatility: Suitable for steam boilers, air systems, or liquid applications not harmful to brass or copper.
• Rugged Construction: Designed with a maximum allowable pressure of 50 psi to withstand system surges.
• Universal Connectivity: Standard 1/4 inch NPT connection simplifies integration into existing HVACR manifolds.

• How do you adjust the P47AA-1 setpoints? Use the internal adjusting screws to set the cut-in point first; the differential screw then determines the cutout point relative to your primary setting.
• What is the maximum ambient temperature for this control? This unit is rated for ambient environments between -30°F and 140°F.
• Does this model require a manual reset? No, the P47AA-1 features an automatic reset; for manual reset requirements, refer to the P47AB series.

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.