Checking Procedures For Other Main Parts - Hitachi FSXN Series Service Manual

8 Troubleshooting

8.7.3 Checking procedures for other main parts

(1) High voltage discharge work for replacing parts
C A U T I O N
Carry out this high voltage discharge work to prevent electric shock.
Procedure
(a) Turn OFF the main switches and wait three minutes. Check to make sure high voltage is not present. If LED201 is ON
after the start-up and OFF after the power supply is turned OFF, the voltage will decrease lower than DC 50V.
(b) Connect connecting wires to an electrical solder bit.
(c) Connect the cables to terminals, P and N of the IPM. => The discharge is started, which will heat up solder bit. Be careful
not to short-circuit between terminals P and N.
(d) Wait 2 or 3 minutes and measure the voltage once again. Make sure no voltage is present.
Plug
Solder Bit
Connecting Wires
(2) Method for checking the transistor module (IPM).
External appearance and internal circuit of transistor module.
Procedure:
Remove all the terminals from the transistor module before the check. If steps (a) and (d) are carried out and the results
are satisfactory, the transistor module is normal. Measure with the multimeter set under 1 kΩ range. Do not use a digital
multimeter.
267
SMGB0065 rev. 1 - 12/2010
Transistor Module (IPM)
Drive Circuit
Drive Circuit
Drive Circuit
Drive Circuit
Drive Circuit
Drive Circuit
Drive Circuit
Sensor
Over Heating
Protection Circuit
P
U
U
W
B
N
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