Johnson Controls P499ACS-401 Pressure Transducer

The Johnson Controls P499ACS-401 is a high-precision electronic pressure transducer engineered for demanding HVACR applications. This stainless steel pressure sensor features a single-piece machined 17-4PH construction, effectively eliminating the risk of refrigerant loss by removing O-rings and welds from the pressure path. Designed with digital compensation, the P499ACS-401 operates reliably within a -1 to 8 bar pressure range, maintaining accuracy despite ambient temperature swings, high humidity, and icing. This unit outputs a standard 4 to 20 mA signal, making it a critical component for fan speed control, pump monitoring, and compressor management in commercial refrigeration systems. The 1/4" SAE 45-degree flare external thread ensures a secure fit onto standard refrigeration ports, while the integrated shielded cable electrical connection minimizes electromagnetic interference in complex industrial environments. Whether you are managing ammonia or non-corrosive refrigerants, this durable transducer provides the repeatability and long-term stability required for professional-grade pressure monitoring and process control.

• Hermetically Sealed Design: The 17-4PH stainless steel port provides a leak-proof system suitable for ammonia and standard HCFC/HFC refrigerants.
• Industrial-Grade Output: Delivers a consistent 4 to 20 mA analog signal for high-resolution input to PLCs and environmental controllers.
• Broad Compatibility: The 1/4" SAE flare connection and slender body design allow for easy installation in tight spaces using deep-socket wrenches.
• Robust Environmental Protection: IP67-rated electronics are specifically built to withstand condensation and thermal cycling in cooling applications.

What is the wiring pinout for the 4-20 mA output?
In a typical two-wire 4-20 mA configuration, the red wire remains the supply voltage while the white wire acts as the signal output. Always verify your specific controller’s requirements for shielded cable grounding to prevent signal noise.

Can this transducer be used on the high-side or low-side?
With a range of -1 to 8 bar, this model is primarily utilized for low-side suction pressure monitoring or low-pressure stage applications in multi-stage systems.

Is this model compatible with ammonia (R-717)?
Yes, the stainless steel construction and lack of internal O-rings make it suitable for ammonia and almost all other non-corrosive pressure media.

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.