Johnson Controls W351AB-2 Humidity Control

The Johnson Controls W351AB-2 Humidity Control is a professional-grade electronic humidity control designed for precise relative humidity management in demanding environments like computer rooms, pharmaceutical manufacturing, and clean rooms. This System 350 electronic control operates bridging a 10% to 90% RH setpoint range with a field-adjustable 2% to 10% RH differential. Engineered for flexibility, it features a SPDT relay output and a built-in 12 VDC power supply specifically to drive humidity transmitters, eliminating the need for external power for your sensing elements. The unit accepts a standard 0-10 Vdc input signal and is built into a rugged NEMA 1 enclosure suitable for surface or DIN rail mounting. Designed to work seamlessly with HE-67S3-0N0BT or HE-67S3-0N00P transmitters, this humidity controller provides reliable staging for both humidification and dehumidification equipment. Its modular design allows for rapid field integration with S351 stage modules and D351 display modules via 5-pin connectors, ensuring simplified wiring for complex multi-stage HVACR applications.

• Dual-Mode Functionality: Field-selectable modes allow for dedicated humidification or dehumidification staging depending on system requirements.
• Integrated Transmitter Power: Includes an onboard 12 VDC supply to power 0-10 VDC humidity sensors, reducing overall component count and installation time.
• Modular Scalability: Part of the Johnson Controls System 350 family, allowing for easy expansion with additional stage or display modules through plug-together connections.
• Precision Calibration: Tight 2% to 10% RH differential adjustments provide granular control over equipment cycling to maintain stable indoor air quality.

What humidity transmitters are compatible with the W351AB-2?
This control is optimized for use with the Johnson Controls HE-67S3 series, including both wall-mount (0N0BT) and duct-mount (0N00P) versions that output a 0-10 Vdc signal.

Does this unit come with a built-in sensor?
No, the W351AB-2 is the control module only and requires a separate humidity transmitter to provide the input signal.

Can I mount this on a standard DIN rail?
Yes, the housing is designed for versatile mounting, supporting both flat surface attachment and standard 35mm DIN rail installations.

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.