Simple Check On Inverter Circuit Components - Mitsubishi Electric R410A Service Handbook

[8-9 Troubleshooting Inverter Problems (TLMU) ]
8-9-13

Simple Check on Inverter Circuit Components

Turn off the power of the unit and leave it turned off for 10 minutes. Check that the voltage of the electrolytic capacitor (inverter
main circuit) is 20 VDC or below. Then, remove the relevant parts from the control box.
Before checking, turn the power off and remove the parts to be checked from the control box.
Part name
IGBT module Refer to the following page(s). [8-9-16 Troubleshooting Problems with IGBT Module](page 274)
Diode stack Refer to the following page(s). [8-9-15 Troubleshooting Problems with Diode Stack](page 274)
IPM (Intelligent Refer to the following page(s). [8-9-14 Troubleshooting Problems with Intelligent Power Module](page
power module) 273)
Rush current <P72, P96, P120, P144 models>
protection resis- Measure the resistance between terminals: 22 ±10%
tor <P168 model>
R1(R2) Measure the resistance between the + terminal on the diode stack and terminal TB31. (*Can be mea-
sured without the need to remove the noise filter board): 22 ±10%
Electromagnetic
relay
72C
Test button
DC reactor DCL Measure the resistance between terminals: 1
Measure the resistance between terminals and the chassis:
Current sensor <P168 model>
ACCT Disconnect the CNCT2 connector and measure the resistance between terminals: 280 ± 30
1 - 2 PIN (U-phase),3 - 4 PIN (W-phase)
HWE14080
This electromagnetic relay is rated at 200VAC and is driven by a coil. The resistance between the
coils in row A cannot be measured with a tester.Check only for shorting.
Installation direction
Row Row Row Row
A B C D
A2 44 34 24 14
A1 43 33 23 13
ACCT-W
*Check the ACCT connection phase and the
direction of the connection
Judgment method
<P72, P96, P120, P144, models>
Check point
Row
Coil
Row A
E
Row B to Row E
Contact
<P168 model>
Check point
Between No. 1 pin and
Coil
No. 3 pin of the CN03 on
the noise filter board
+ terminal on the diode
stack and terminal
Contact
TB31 on the noise filter
or lower (almost 0 )
IPM
W V U
ACCT-U
W U
- 272 -
Checking criteria
Not to be short-circuited
With the test button
turned off :
With the test button
turned on : 0
Checking criteria
Not to be short-circuited
With the test button
turned off :
With the test button
turned on : 0
GB