Hoffman Controls 814-10EH Control

The Hoffman Controls 814-10EH is a line-voltage, solid-state fan speed controller designed for precise head pressure control in air-cooled condensers. Engineered for versatile field application, this electronic voltage starter functions as a triac-based motor speed control, maintaining optimal refrigerant pressures by modulating condenser fan motor RPM in response to liquid line temperatures or pressures. This specific model supports a wide operating range of 120V to 480V AC and can handle an inductive load up to 10 Amps. It utilizes a 24V control circuit for integration with standard HVAC safety strings and operating controllers. For technicians managing low ambient cooling cycles, the 814-10EH prevents evaporator freeze-ups and compressor slugging by ensuring the condensing unit maintains a stable thermal profile even when outdoor temperatures drop. Its rugged construction is built for HVACR contractor demands, offering a reliable alternative to cycling fans or using dampers.

Key Technical Benefits

• Universal Voltage Compatibility: Operates across 120V, 208V, 240V, and 480V systems, reducing the need for multiple truck-stock SKUs.
• Precise Head Pressure Regulation: Maintains consistent condensing pressure through infinite variable speed control rather than abrupt on/off cycling.
• Heavy-Duty 10A Rating: Capable of driving larger PSC (Permanent Split Capacitor) motors used in commercial refrigeration and air conditioning.
• Low Ambient Capability: Enables reliable cooling operation in sub-freezing conditions by accurately modulating airflow.
• Simplified 24V Interface: Easily interfaces with existing low-voltage control logic for seamless system commissioning.

Common Technical Questions

Can the 814-10EH be used with ECM motors?
No, this controller is specifically designed for single-phase PSC or shaded pole motors that are rated for variable voltage speed control. Using this with a standard ECM may damage the motor's internal inverter.

How does this unit sense the pressure changes?
The 814-10EH typically interfaces with a thermistor sensor or a pressure transducer. It converts these inputs into a proportional output voltage to adjust fiber-optic pulse widths or phase-angle firing for the motor.

Is an additional transformer required for the 24V circuit?
While the 814-10EH manages high-voltage loads, the 24V signal must be provided by the system's existing class 2 transformer or a dedicated external power source to trigger the control logic.

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.