Hitachi X200 Series - Manual (Page 218)

IGBT Test Method
The following procedure will check the inverter transistors (IGBTs) and diodes:
1. Disconnect input power to terminals [R, S, and T] and motor terminals [U, V, and W].
2. Disconnect any wires from terminals [+] and [–] for regenerative braking.
3. Use a Digital Volt Meter (DVM) and set it for 1Ω resistance range. You can check the
status of the charging state of terminals [R, S, T, U, V, W, +, and –] of the inverter
and the probe of the DVM by measuring the charging state.
Table Legend Almost infinite resistance: ≅ ∞ Ω Almost zero resistance: ≅ 0 Ω
DVM DVM DVM Part
+ –
Measured
Value
Part
+ –
Measured
Value
Part
+ –
Measured
Value
[R] [+1] ≅ ∞ Ω [S] [–] ≅ 0 Ω [W] [+] ≅ ∞ Ω D1
[+1] [R] ≅ 0 Ω
D5
[–] [S] ≅ ∞ Ω
TR3
[+] [W] ≅ 0 Ω
[S] [+1] ≅ ∞ Ω [T] [–] ≅ 0 Ω [U] [–] ≅ 0 Ω D2
[+1] [S] ≅ 0 Ω
D6
[–] [T] ≅ ∞ Ω
TR4
[–] [U] ≅ ∞ Ω
[T] [+1] ≅ ∞ Ω [U] [+] ≅ ∞ Ω [V] [–] ≅ 0 Ω D3
[+1] [T] ≅ 0 Ω
TR1
[+] [U] ≅ 0 Ω
TR5
[–] [V] ≅ ∞ Ω
[R] [–] ≅ 0 Ω [V] [+] ≅ ∞ Ω [W] [–] ≅ 0 Ω D4
[–] [R] ≅ ∞ Ω
TR2
[+] [V] ≅ 0 Ω
TR6
[–] [W] ≅ ∞ Ω
NOTE: The resistance values for the diodes or the transistors will not be exactly the
same, but they will be close. If you find a significance difference, a problem may exist.
NOTE: Before measuring the voltage between [+] and [–] with the DC current range,
confirm that the smoothing capacitor is discharged fully, then execute the tests.
6−15
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