Hoffman Controls 865D Control

The Hoffman Controls 865D is a high-performance, microprocessor-based three-phase head pressure control engineered for low-ambient operation in commercial HVACR systems. Serving as the direct replacement for the 865-3AA series, this controller utilizes advanced phase rotation detection to safeguard equipment against phase irregularities and ensure proper motor orientation. By dynamically modulating the condenser fan speed, the 865D maintains optimal refrigerant head pressure, preserving the necessary pressure differential across expansion valves even under fluctuating outdoor temperatures. This unit is specifically designed for 208-230/460Vac applications and is limited to motors ranging from 1/2 to 2 HP. It supports continuously variable speed High Slip/Ventilated (HS/V) induction motors and includes a NEMA 3R weatherproof enclosure for reliable field installation in harsh environments. Technicians can configure the unit for low ambient fan control using the included liquid line temperature sensor or via 0-10Vdc/4-20mA pressure transducer inputs.

• Provides built-in phase rotation detection and fault protection to prevent compressor and motor damage.
• Ensures stable refrigeration system performance by regulating air volume through the condenser in low ambient conditions.
• Features dual-mode functionality, allowing for use as a head pressure control or a manual three-phase fan speed control.
• Equipped with onboard LED diagnostic indicators to confirm power status, motor speed, and input power faults.
• Direct replacement for obsolete 865-3AA controllers, facilitating simplified retrofits for 3-phase induction motors.

How does this control protect the compressor from incorrect wiring?
The 865D includes integrated phase rotation detection that monitors the sequence of the incoming three-phase power. If a phase reversal or single-phasing condition is detected, the unit triggers a fault protection sequence to prevent the motor from running in reverse or overheating.

What type of motors are compatible with the 865D?
This controller is designed for three-phase condenser fan motors (850/1150 RPM) that are rated for continuous variable speed operation. For modulating applications, motors must be High Slip/Ventilated (HS/V) and 56 frame or equivalent as approved by the motor manufacturer.

Can I use a pressure transducer instead of the included temperature sensor?
Yes, the 865D is versatile and will automatically sense and accept 0-10Vdc or 4-20mA signals from external pressure transducers, allowing for direct pressure-based modulation if preferred by the contractor.

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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.