Mitsubishi P336 User Manual
[
IX Troubleshooting ]
- 266 -
HWE09120
GB
(5) Simple checking procedure for individual components of main inverter circuit
Before inspecting the inside of the control box, turn off the power, keep the unit off for at least 10 minutes, and confirm that
the voltage between FT-P and FT-N on INV Board has dropped to DC20V or less.
the voltage between FT-P and FT-N on INV Board has dropped to DC20V or less.
(6) Troubleshooting for IGBT Module
Measure the resistances between each pair of terminals on the IGBT with a tester, and use the results for troubleshooting.
The terminals on the INV board are used for the measurement.
The terminals on the INV board are used for the measurement.
1) Notes on measurement
Check the polarity before measuring. (On the tester, black normally indicates plus.)
Check that the resistance is not open ( ohm) or not shorted (to 0 ohm).
The values are for reference, and the margin of errors is allowed.
The result that is more than double or half of the result that is measured at the same measurement point is not allowed.
Disconnect all the wiring connected the INV board, and make the measurement.
2) Tester restriction
Use the tester whose internal electrical power source is 1.5V or greater
Use the dry-battery-powered tester.
Use the dry-battery-powered tester.
(The accurate diode-specific resistance cannot be measured with the button-battery-powered card tester, as the applied volt-
age is low.)
age is low.)
Use a low-range tester if possible. A more accurate resistance can be measured.
Part name
Judgment method
IGBT module
See "Troubleshooting for IGBT Module ". (IX [4] - 6 - (6) )
Rush current pro-
tection resistor
R1, R5
tection resistor
R1, R5
Measure the resistance between terminals R1 and R5: 22 ohm
10%
Electromagnetic
relay
72C
relay
72C
This electromagnetic relay is rated at DC12V and is driven by a coil.
Check the resistance between terminals
Check the resistance between terminals
DC reactor DCL
Measure the resistance between terminals: 1ohm or lower (almost 0 ohm)
Measure the resistance between terminals and the chassis:
Measure the resistance between terminals and the chassis:
1
6
5
2
3
4
Upper
Installation
direction
direction
Check point
Checking criteria( )
W
Between Terminals 5 and 6
Between Terminals 1 and 2
Between Terminals 3 and 4
Between Terminals 3 and 4
Not to be short-circuited
(Center value 75 ohm)
Coil
Contact
[YJMU-A]