6-1 Inspection and Maintenance Note 2: A nearly infinite value is shown in a no-conduction state. However, the value may not be infinite if the momentary conduction occurs through the influence of the smoothing capacitor The value shown ranges from a few to a few dozen Ω in a conduction state. The Inverter or converter is in good shape if the values from various parameters are nearly equal, though they are not consistent depending on the types of elements or testers. Note 3: The BRD unit is provided for the Inverters with 22 kW or lower capacity.
Converter unit +1 P/+2 RB BRD unit Inverter unit R/L1 S/L2 T/L3 C 6 Inspection and Maintenance N/- 6-8 Tester polarity Measurement value + (red) - (black) Converter unit D1 R/L1 +1 No conduction +1 R/L1 Conduction D2 S/L2 +1 No conduction +1 S/L2 Conduction D3 T/L3 +1 No conduction +1 T/L3 Conduction D4 R/L1 N/- Conduction N/- R/L1 No conduction D5 S/L2 N/- Conduction N/- S/L2 No conduction D6 T/L3 N/- Conduction N/- T/L3 No conduction Inverter unit TR1 U/T1 P/+2 No conduction P/+2 U/T1 Conduction TR2 V/T2 P/+2 No conduction P/+2 V/T2 Conduction TR3 W/T3 P/+2 No conduction P/+2 W/T3 Conduction TR4 U/T1 N/- Conduction N/- U/T1 No conduction TR5 V/T2 N/- Conduction N/- V/T2 No conduction TR6 W/T3 N/- Conduction N/- W/T3 No conduction BRD unit TR7 RB P/+2 No conduction P/+2 RB Conduction RB N/- No conduction N/- RB No conduction D1 D2 D3 D2 D3 1 2 D4 D5 D6 D5 D6 TR1 TR2 TR3 TR7 U/T1 V/T2 W/T3