Hoffman Controls 865D-HP Pressure Controller

The 865D-HP Control is an improved microprocessor based Three Phase Head Pressure Control that is a direct replacement for the 865-3AA, 865D and 865D-2 Series Controls. The 865D HP can be used as a Fan Modulating Head Pressure Control or a Fan Cycling Head Pressure Control via a selection switch with up to two Temperature Sensor inputs or one 0-10Vdc or 4-20mA Pressure Transducer input. The Control varies the air volume through the condenser thus regulating head pressure for proper heat rejection in low ambient conditions.

The 865D-HP Control maintains a minimum pressure differential across the expansion valve to provide the proper rated capacity for all ambient operating conditions regardless of refrigerant types. This maintains proper system operating conditions, while assuring proper suction pressure (evaporator temperature) over the anticipated ambient operating range.

The 865D-HP Control is limited to 1/2 to 2 HP, three phase, 208-230/460Vac, direct connected, propeller type, condenser fan motor applications. Modulating applications require continuously variable speed High Slip tolerant/Ventilated (HS/V), 850/1150 RPM, direct drive, 56 Frame, vertical shaft designed motors approved by the motor manufacturer for continuous variable speed operation. The optional Fan Cycling Mode can use lower quality motors not designed for variable speed applications.

The 865D-HP Control is supplied with a NEMA 3R r a in proof enclosure for field installation in poor weather/ambient conditions and includes an encapsulated Temperature Sensor and mounting hardware that is designed for fast response of liquid line temperature changes