Johnson Controls P70MA-11 Pressure Control

The Johnson Controls P70MA-11 is a robust dual pressure control engineered for high-pressure refrigeration and air conditioning systems. This SPST (Single Pole Single Throw) controller features a low side range of 20" Hg to 100 psi and a high side range of 100 to 425 psi, making it a standard replacement for R-22, R-404A, and R-507 applications. Designed with a NEMA 1 enclosure, this unit ensures reliable operation in demanding mechanical rooms. The P70MA-11 incorporates a high side manual reset lockout switch, providing critical protection against high discharge pressures. As a direct equivalent to the P70MA-11C, this model is built for field service longevity, utilizing a bellows-actuated design for precise response times. Professionals prefer this P70 series pressure switch for its durability and ease of installation, though this specific model is supplied without an adjustment knob to prevent unauthorized setpoint tampering in the field.

Key Benefits

• Dual Pressure Monitoring: Consolidates both high and low-pressure protection into a single, compact SPST pressure control housing.
• Manual Reset Lockout: The high-side manual reset adds a layer of safety, requiring technician intervention to verify system integrity before restarting.
• Cross-Compatibility: Fully interchangeable with the P70MA-11C, ensuring seamless integration into existing Johnson Controls HVAC setups.
• Rugged Construction: Features a NEMA 1 enclosure and heavy-duty bellows capable of withstanding the vibrations and thermal cycles of commercial refrigeration.
• Universal Refrigerant Support: Optimized for use with non-corrosive refrigerants including R022, R134A, and R404A.

Common Questions

How do I adjust the differential on the P70MA-11?
The low side differential is set at a factory standard, typically around 6 to 50 psi. Adjustments should be made using internal screws, as this model does not include external adjustment knobs to ensure setpoint security.

Is this control suitable for R-410A systems?
No, the 425 psi high side limit is designed for lower pressure refrigerants like R-22 or R-404A. For R-410A high pressure cutouts, a control rated for at least 650 psi is recommended.

Can the P70MA-11 replace a P70MA-1?
While the P70 series shares mounting footprints, always verify the specific pressure ranges and reset requirements. The P70MA-11 is specifically characterized by its manual reset on the high-pressure side.

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.