[4] IGBT Measurement
Resistance Measurement
Allowable Value
From
To
+
U
50kohm or more
+
V
+
W
U
+
50 ohm or less
V
+
W
+
-
U
50 ohm or less
-
V
-
W
U
-
50kohm or more
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)
Measurement on the ISPM
Disconnect the cooling FAN
Resistance Measurement
Allowable Value
From
To
Pin (Red)
Pin (Black)
20kohm or more
Pin (Black)
Pin (Red)
50ohm or less
( relative check is important )
[6] Cooling FAN
Disconnect the cooling FAN and measure impeadance of FAN circuit.
Resistance Measurement
Allowable Value
From
To
Red wire
Black wire
50kohm or less
Black wire
Red wire
100kohm or more
( relative check is important )
6-3/E
DC current detecting
resistor (shunt resistor)
(Order of mili ohm)
+
U
W
V