Hoffman Controls 706-123SB Control

The Hoffman Controls 706-123SB is a robust, field-adjustable electronic fan speed controller engineered for demanding HVACR applications. This 10 Amp fan speed control utilizes phase proportioning to provide precise, manually adjustable speed regulation for single-phase permanent split capacitor (PSC) and shaded pole motors. Designed for versatile integration, it supports a broad nominal voltage range from 120V to 277V, making it a standard choice for direct-connected propeller blades and centrifugal blowers. As a technician, you will appreciate the built-in minimum speed adjustment pot located on the side of the housing. This critical feature allows you to set a baseline RPM to prevent motor stalling and ensure proper cooling, especially when dealing with varying motor loads. The 706-123SB is optimized for performance in ambient temperatures between 0?C and 60?C. When installing, always verify that the motor is rated for speed regulation and ensure the FLA current rating is not exceeded at any point in the operating curve to maintain thermal stability.

Key Benefits

• Universal Voltage Compatibility: Operates seamlessly across 120V, 208V, 240V, and 277V systems, reducing the need for multiple SKUs.
• Adjustable Minimum Speed: Features a side-mounted potentiometer to set a minimum RPM limit, protecting the motor from stall conditions.
• High Amperage Capacity: Rated for up to 10 Amps, providing reliable control for larger blower and pump applications.
• Reliable Phase Proportioning: Delivers proportional speed control for open-frame motors and squirrel cage fans.

Common Questions

What types of motors are compatible with the 706-123SB?
This controller is specifically designed for single-phase permanent split capacitor (PSC) or shaded pole motors. It is not intended for use with three-phase motors or synchronous motors that are not designed for phase-proportioning speed regulation.

How do I prevent the motor from humming or overheating?
Motor noise and temperature rise are common during phase-controlled speed reduction. To mitigate this, ensure the motor has thermal overload protection and use the adjustment pot to keep the minimum speed at approximately one-half of the full-rated speed.

Can this be used for applications other than fans?
While primarily used for air-moving equipment like blowers and propellers, it can be applied to other non-air-moving motor drive requirements, such as certain pump types, provided the FLA ratings are strictly observed.

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.