How to check the IGBT break or not:

1. Use the diode position of the multimeter, the red pen to point the three-phase output terminals (U, V, W), the black pen point “+”, measure whether the three-phase bridge on the inverter part is normal or not, and the multimeter shown about 0.4V is Normal, short circuit or open circuit means damage, as shown in Fig.

2. Use the multimeter diode position, the red pen point “-”, and the black pens point the three-phase input terminals (U, V, W). Measure whether the three-phase lower bridge of the rectifier part is normal or not. The multimeter showing about 0.4V is Normal, short circuit or open circuit shows damage, as shown in Fig.1