Mitsubishi Electric GU-D08 80173-109-01

The GU-D08 is a SCR thyristor power assembly for Mitsubishi legacy medium voltage soft starter and drive units, part drawing number 80173-109-01. This GU-D08 integrates paired SCR thyristors, snubber circuits and built-in temperature sensing thermistor for phase-angle control, responsible for motor voltage ramp regulation during soft start. The code 80173-109-01 is the internal drawing and part revision number for this assembly.

This unit includes over-temperature, overcurrent and surge suppression protection. The thermal sensor signal feeds back to the drive control board to trigger thermal alarm and trip. It is designed to mount on dedicated air-cooled heat sink, and it requires matched gate trigger board to provide firing pulses for SCR control. Isolation design reduces interference between power circuit and low voltage control logic. It is used in pairs or sets for three-phase soft-start power stages.

The GU-D08 is widely deployed in fan, pump and compressor medium voltage soft starter cabinets. This legacy Mitsubishi power assembly is discontinued. Most available GU-D08 80173-109-01 units are tested surplus spare parts for soft starter overhaul and emergency replacement. Gate trigger signal, heat sink mounting dimension and thermal wiring pin definition must be verified before replacement.