Hitachi SJ100 SERIES Service Manual page 32

[4] IGBT Measurement
Resistance Measurement
From
+
+
+
U
V
W
-
-
-
U
V
W
If the result is out of its spec, replace the unit.
Please note that this cannot cover 100% to find IGBT failure because if the power devices in failure,
sometimes you can find the failure in components while they are activated. (You cannot find the failure
while they are not activated.)
[5] Cooling FAN voltage circuit in the ISPM (PV 24N)
Check "b92" is preset ""00 (FAN to be worked) and disconnect the cooling FAN
Resistance Measurement
From
Pin(up) (Red)
Pin(up) (Black)
( relative check is important )
[6] Cooling FAN
Disconnect the cooling FAN and measure impedance of FAN circuit.
Resistance Measurement
From
Red wire
Black wire
( relative check is important )
[7] BRD(RB,+,-)
Disconnect BRD resistor.
Red wire, Black wire mean tester's wires.
Resistance Measurement
+
Black wire
Red wire
Resistance Measurement
RB
Black wire
Red wire
To
U
V
W
+
+
+
U
V
W
-
-
-
To
Pin(down) (Black)
Pin(down) (Red)
To
Black wire
Red wire
RB
Red wire 100kohm - 400kohm
Black wire
-
100kohm – 700kohm
Red wire
Black wire
Allowable Value
50kohm or more
50 ohm or less
50 ohm or less
50kohm or more
Allowable Value
20kohm or more
50ohm or less
Allowable Value
50kohm or less
100kohm or more
Allowable Value
Diode drop V
8ohm – 14ohm
Allowable Value
Diode drop V
2kohm – 4kohm
6-3/E
DC current detecting
resistor (shunt resistor)
(Order of mili ohm)
Allowable Value
0.3 – 0.5
OL
(only reference)
Allowable Value
OL(initial charge)
OL
(only reference)
+
U
V
W
Rsh