Johnson Controls A350PS-2 Temperature Control

The Johnson Controls A350PS-2 is a field-proven electronic temperature control designed for precise Proportional plus Integral (P+I) control in demanding HVACR applications. Operating on 24VAC, this System 350 module provides a versatile 0-10VDC or 0-20mA analog output, making it a reliable choice for modulating valves, dampers, or variable speed drives. With a broad setpoint range of 90 to 250 degrees F (32 to 121 degrees C) and an adjustable differential of 2 to 30 degrees F, the A350PS-2 ensures tight thermal regulation. This unit comes standard with an A99BC-25 silicon sensor, known for its high-impedance stability and accuracy over long lead lengths. Designed for DIN rail or surface mounting, it integrates seamlessly with other System 350 modules to build a custom HVAC control system. This modulating temperature controller eliminates the offset common in proportional-only systems, maintaining the setpoint regardless of load fluctuations.

• P+I Control Logic: Eliminates temperature droop for superior accuracy in modulating HVAC applications.
• Output Versatility: Field-selectable 0-10VDC or 0-20mA signals ensure A350PS-2 compatibility with various actuator brands.
• Rugged Sensor Performance: The included A99BC-25 PTC sensor provides reliable feedback in high-temperature environments.
• Modular Design: Plugs directly into other System 350 components for streamlined commercial temperature control setups.
• Diagnostic Convenience: Features a built-in LED to indicate power and output status, simplifying field troubleshooting.

How do I calibrate the A350PS-2 for a 4-20mA output?
The unit is natively capable of 0-20mA; for a 4-20mA application, you must calibrate the input signal or utilize the internal jumpers to align the output scale with your specific actuator requirements.

Can I extend the sensor lead on the A99BC-25?
Yes, because it is a silicon-based A99 series sensor, you can extend the wire up to several hundred feet using standard 18 AWG shielded cable without significant signal degradation or the need for frequent recalibration.

Is the A350PS-2 suitable for steam applications?
Given its 250°F upper limit, it is frequently used in low-pressure steam or hot water modulation, provided the sensor is installed in a properly rated thermowell.

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.