Mitsubishi Electric R410A, Service Handbook

Page: 281 / 346

[8-9 Troubleshooting Inverter Problems (TLMU) ]
- 272 - HWE14080 GB
8-9-13 Simple Check on Inverter Circuit Components
Œ
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.
Œ
Before checking, turn the power off and remove the parts to be checked from the control box.
Part name Judgment method
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
power module) Refer to the following page(s). [8-9-14 Troubleshooting Problems with Intelligent Power Module](page
273)
Rush current
protection resis-
tor
R1(R2) <P72, P96, P120, P144 models>
Measure the resistance between terminals: 22
ȍ
±10%
<P168 model>
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
ȍ
±10%
Electromagnetic
relay
72C
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.
DC reactor DCL Measure the resistance between terminals: 1
ȍ
or lower (almost 0
ȍ
)
Measure the resistance between terminals and the chassis:
Current sensor
ACCT <P168 model>
Disconnect the CNCT2 connector and measure the resistance between terminals: 280
ȍ
± 30
ȍ
1 - 2 PIN (U-phase),3 - 4 PIN (W-phase)
Check point
Row A
Not to be short-circuited
Row B to Row E
Installation direction
Test button
Row
A
Row
B
Row
C
Row
D
Row
E
A2 44 34 24 14
43 33 23 13 A1
<P72, P96, P120, P144, models>
Coil
Contact
Check point
Not to be short-circuited
<P168 model>
Coil
Contact
Checking criteria
Checking criteria
Between No. 1 pin and
No. 3 pin of the CN03 on
the noise filter board
+ terminal on the diode
stack and terminal
TB31 on the noise filter
With the test button
turned off :
With the test button
turned on : 0
With the test button
turned on : 0
With the test button
turned off :
U
U
V
IPM
*Check the ACCT connection phase and the
direction of the connection
W
ACCT-W
W
ACCT-U