Mitsubishi Electric PEFV-P72NMHSU-E Technical & Service Manual page 56

4. Simple check on the main inverter circuit components
Turn off the power supply, take the following components out of the control box, and then check the components.
Parts name
Diode bridge
Inrush current limiting resistor R
AC reactor (ACL)
Current sensor
ACCT
THHS sensor
5. Troubleshooting the diode bridge
Measure the resistance between terminals of the diode bridge with a tester, and use the measured value for troubleshooting.
1) Read before taking measurements.
Check the polarity before taking measurements. Black is positive on a regular multimeter when it is used to measure resis-
tance.
Check that the circuit is not completely open (
These resistance measurement values are provided only as a guide, and small deviations from these values are allowed.
If the resistance between a given terminal and other terminals all fall within a range of minus 50% and plus 100%, the resis-
tance is normal.
2) Tester restrictions
Use a tester that has an internal voltage supply of 1.5 V or greater.
Use a dry-battery-powered tester.
(An accurate diode resistance measurement cannot be obtained with a button-battery-operated card tester because of its low
applied voltage.)
Use a tester that can measure in small increments.
It will allow for more accurate measurement.
3) External view
+
~(L)
4) Internal circuit diagram
+
L
N
-
6. Precautions for inverter parts replacement
1) Check for faulty or loose wiring.
To avoid damage to the IPM, thoroughly check the wiring to the main circuit components in the diode bridge.
2) Securely attach the diode bridge with mounting screws.
HWE1017B
Refer to "5. Troubleshooting the diode bridge".
Measure the resistance between terminals : 22 Ω
Measure the resistance between terminals. : 1 Ω or less
Measure the resistance between terminals and the chassis:
Disconnect the CNCT2 connector, and check the resistance between the terminals.
580 Ω 30 Ω
Disconnect the connector CNTH, and measure the resistance between connector ter-
minals.
Check that the terminals are not short-circuited (0 Ω) or open-circuited (
Ω) or short-circuited (- 0 Ω).
<Reference values for resistance check>
~(N)
+
-
-
Red (-)
~(L)
~(N)
- 50 - 50
Evaluation criteria
10%
Black ( + )
+ - ~(L)
- - 5 - 200 Ω
- -
5 - 200 Ω
5 - 200 Ω
Ω).
~(N)
5 - 200 Ω
- -
- -
GB