Mitsubishi Heavy Industries SRRM40HENG-L, Handbook, Page: 46 / 1106

44
SRK-GZ
(6) Inspection procedures of indoor electrical equipment
(7) Inspection procedures of inverter assembly
When the inverter is judged to be defective as a result of diagnosis of the item (2) above, inspect the inverter assembly as follows.)
(a) Diagnosis procedure
(For further details, refer to the Inspection points of outdoor unit on the next page.)
Notes (1) Since the communication timing signal is transmitted only when the
52C is turned ON, check it under the operating condition.
(2) Check the voltage on the terminal block.
¡
Power supply: Between
1
~
2
(AC 220/240V)
¡
Signal: Between
2
~
3
(Changing between DC 0~Approx. 12V)
NO
YES
YES
YES
YES
NO
NO
NO
NO
YES
NO
YES
YES
NO
YES
Is fuse (3.15A) blown?
Indoor electrical equipment
are normal.
Is voltage applied between CNC
1
~
2
at transformer’s secondary
side? (Approx. 12V)
Is voltage applied between
terminals
1 ~ 2 on terminal
block? (220/240V)
Is DC 0~12V detected between
terminals
2 ~ 3 on terminal
block?
Check power supply,
replace transformer.
Replace fuse.
Replace PCB.
Replace PCB.
1
2
3
Is visual check result OK?
Defective PCB
(Including power
transistor)
Is voltage applied to electrolytic
compressor? (Approx. DC 300V)
Is electrolytic capacitor good?
Is voltage applied between 3 ~ 4
of noise filter? (AC 220/240V)
Defective PCB
Defective noise filter
Defective electrolytic capacitor
Checks
1
and
3
must be made under the operating
condition.
Before checking
2
, make sure to turn power off, dis-
charge electricity from the capacitor and check the re-
sidual voltage (10V or less) with a tester for safety.
Soldering iron