ABB ACH550-UH-03A3-4 Variable Frequency Drive

ABB ACH550-UH-03A3-4 is a three-phase HVAC variable frequency drive designed to power equipment on 380–480 VAC mains. It delivers 1.5 HP output to drive motors in fans, pumps, and compressors, enabling precise speed control and energy-efficient operation in commercial and light-industrial HVAC systems. The UH variant includes a bypass enclosure, providing a mechanical bypass that allows the load to be reconnected directly to the mains for maintenance or fault scenarios without removing power from the drive assembly. As part of ABB's ACH550 family, this model targets HVAC applications on 380–480 VAC three-phase power; the 03A3-4 designation identifies the 1.5 HP rating within that voltage range. The combination of voltage, phase, horsepower, and bypass capability makes it well suited for retrofit or new installations where a dedicated HVAC drive with a bypass option is desired.