Mitsubishi Electric CITY MULTI PQRY-P200YMF-B Service Handbook page 95

6) Individual parts failure judgment methods.
Part name
Diode Stack (DS)
Transistor Module (TRM)
Electromagnetic Contactor (52C)
Rush current protection resistor (R1, 5)
DC reactor (DCL)
Cooling fan (MF1)
Transformer (T01)
[Caution at replacement of inverter parts]
1
The transistor module and INV board should be replaced together at the same time.
When the transistor module is damaged, the INV board may possibly be broken, and the use of the broken INV
board damages the normal transistor module. Therefore, replace the transistor module and INV board together at
the same time. However, if the INV board is damaged, judge that the transistor module is faulty, then judge whether
replacement is necessary or not.
2 Fully check wiring for incorrect and loose connection.
The incorrect or loose connection of the power circuit part wiring like transistor module and diode module causes to
damage the transistor module. Therefore, check the wiring fully. As the insufficient tightening of screws is difficult to
find, tighten them together additionally after finishing other works. For the wiring of the base for transistor module,
observe the wiring diagram below carefully as it has many terminals.
3 Coat the grease for radiation provided uniformly onto the radiation surface of transistor/diode modules.
Coat the grease for radiation on the full surface in a thin layer, and fix the module securely with the screw for
fastening. As the radiation grease attached on the wiring terminal causes poor contact, wipe it off if attached.
Refer to "Judging Diode Stack Failure."
Refer to "Judging Transistor Module Failure."
Measure the resistance value at each terminal.
A2 A1
1/L1 3/L2 5/L3
2/T1 4/T2 6/T3
Measure the resistance between terminals: 4.5k~5.5kΩ
Measure the resistance between terminals: 1 Ω or lower
Measure the resistance between the terminals and the chassis: ∞
Measure the resistance between terminals: 0.1k~1.5kΩ
Measure the resistance between terminals on the primary side (CNTR1):
1.0k~2.5kΩ
Measure the resistance between terminals on the secondary side (CNTR):
20~60Ω
–92–
Judgment method
Check Location Judgment Value
A1-A2
1/L1-2/T1
3/L2-4/T2
5/L3-6/T3
0.1k~1.3kΩ
∞