Hitachi WJ200-001L, Instruction Manual

Page: 322 / 680

6
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17
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
Part DVM Measured
Value
Part DVM Measured
Value
Part DVM Measured
Value – + – + – +
D1 [R] [+1]  ∞ Ω D5 [S] [–]  0 Ω TR4 [U] [–]  0 Ω
[+1] [R] 
0 Ω
[–] [S] 
∞ Ω
[–] [U] 
∞ Ω
D2 [S] [+1] 
∞ Ω
D6 [T] [–] 
0 Ω
TR5 [V] [–] 
0 Ω
[+1] [S]  0 Ω [–] [T]  ∞ Ω [–] [V]  ∞ Ω
D3 [T] [+1]  ∞ Ω TR1 [U] [+]  ∞ Ω TR6 [W] [–]  0 Ω
[+1] [T]  0 Ω [+] [U]  0 Ω [–] [W]  ∞ Ω
D4 [R] [–]  0 Ω TR2 [V] [+]  ∞ Ω TR7 [RB] [+]  ∞ Ω
[–] [R] 
∞ Ω
[+] [V] 
0 Ω
[+] [RB] 
0 Ω
TR3 [W] [+] 
∞ Ω
[RB] [–] 
∞ Ω
[+] [W] 
0 Ω
[–] [RB] 
∞ 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.
D1
[R/L1]
D2 D3
D4 D5 D6
[PD/+1] [P/+] [RB]
TR1 TR2 TR3
TR4 TR5 TR6 TR7
[U/T1]
+
[N/
-
]
[S/L2]
[T/L3] [V/T2]
[W/T3]