Maintenance
365
M
ai
n
ten
an
ce
9.2 Diode module and IGBT inspection
Remove the power cables (R, S, T) and the motor output cables (U, V, W).
Confirm that the electrolytic capacitors are fully discharged.
Check the feedthrough status at the inverter terminals (R, S, T, U, V, W, P2,
and N) by measuring the resistance between each terminal using a
multimeter.
If current is flowing between the terminals, a low resistance value
(Ω)
is
measured. If current is not flowing between the terminals, a high resistance
value (M Ω) is measured.
If the capacitors are not fully discharged, a low resistance value may be
measured even if current is not flowing in the circuit. This may result in
incorrect diagnostic procedures.
Refer to the circuit diagram above and test the components on the printed
circuit board. Measure the resistance at the terminals indicated on the circuit
diagram.