Zonefirst ZDB-12X18 12HX18W Parallel 24V 2-Pos S/R

The Zonefirst ZDB-12X18 is a professional-grade 12HX18W Parallel 24V 2-Pos S/R zone damper engineered for high-static HVAC environments. Built with a heavy-duty extruded aluminum frame and 3-inch parallel blades, this bottom-mount zone damper ensures quiet, low-leakage performance in rectangular ductwork. The unit utilizes a 2-wire spring return motor rated for 24VAC, providing a fail-safe open position when de-energized and a powered closed state. With a synchronous motor tested to exceed 250,000 cycles, it is a reliable choice for HVAC zone control systems. This model is 1/4 inch undersized to fit 12x18 ducts without binding and includes a minimum position adjustment screw to manage bypass air without additional components. Designed for contractors, the ZDB series damper supports simple parallel wiring, allowing up to five motors to run on a single 40VA transformer, making it compatible with legacy systems and modern A2L refrigerant safety requirements.

• Fail-Safe Operation: The 2-wire spring return actuator ensures the damper defaults to an open position during power loss, preventing equipment freeze-ups.
• Precision Airflow Management: Integrated minimum position adjustment allows for field-calibrated bypass air, maintaining system static pressure below 1.0” W.C.
• Durable Construction: Features self-lubricating bushings and an extruded aluminum frame for silent operation and long-term reliability in commercial or residential ducts.
• Easy Installation: Bottom-mount design places the motor on the 18-inch dimension, facilitating access in tight plenum spaces.
• High Compatibility: Seamlessly integrates with 24V zone control panels and is field-convertible to power-open/spring-close if required.

How do I wire multiple ZDB dampers to one zone?
You can wire these 24V motors in parallel. Ensure your transformer is adequately sized; a standard 40VA transformer typically handles up to five Zonefirst ZDB dampers.

Can this damper be used with round ductwork?
No, the ZDB-12X18 is a rectangular parallel blade damper. For round applications, you should utilize the Zonefirst RD or RT series.

Is the motor replaceable without removing the damper?
Yes. The motor can be swapped in under a minute by loosening the setscrew on the drive shaft, ensuring minimal downtime for service calls.

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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.