Mitsubishi Heavy Industries FDT28KXE6A Service Manual page 89

Error code
E42
Remote controller:
E42-1, 2*
7-segment display:
*1 E42-1: CM1, E42-2: CM2 *2 E42-1: 1 time flash, E42-2: 2 time flash
1. Applicable model
Outdoor unit
2. Error detection method
When anomalously high output
current of inverter is detected
by the current sensor mounted
in the power transistor
3. Condition of error displayed
When 88A or higher output
current of inverter is detected 4
times within 15 minutes.
4. Presumable cause
• Compressor anomaly
• Leakage of refrigerant
• Power transistor module
anomaly
• Anomalous power supply for
inverter PCB
• Outdoor fan motor anomaly
Note:
In case that there is no the insulation resistance anomaly, the compressor anomaly could be considered.
If this anomaly occurs after replacement of power transistor module and/or inverter PCB, try to replace compressor as well.
If the error does not recur, connect the Mente PC and continue to collect data
LED Green Red
Keeps flashing Stays Off
Indoor
*
Keeps flashing 2
Outdoor
5. Troubleshooting
Diagnosis
Save data for 30 minutes before stopping in Mente PC
Is the
coil resistance and insulation
(megger check) of compressor
motor OK?
YES
Does the outdoor fan run ?
YES
Is 15V
of power for control PCB
detected? Is the outdoor fan motor OK?
(Refer the checking method of
15V in page 46)
YES
Reset power supply and restart
Does E42 recur?
YES
Is it the unit with 2 compressors?
YES
Do you
have inverter checker for
judging whether inverter PCB is
OK or not?
NO
After power OFF,
Remove the 1-3 layers
of control box
Is the
checked result by measuring
the resistance beween each terminal
of power transistor module OK?
(Are there any short-
circuit?)
87
–
Content
Current cut (CM1, CM2)
YES
When
interchanging the
cables between inverter and
YES
compressor, is the compressor
failed to startup
switched?
YES
Is the
checked result by
YES
inverter checker
OK?
–
Countermeasure
Check and save the data of
operating conditions
Check pressure anomaly
Check the operation of
outdoor fan
Replace compressor.
NO
Check the capillary tube
and stariner of oil separator.
If necessary, replace the
capillary tube and strainer
as well.
Repair it according to the
NO
troubleshooting of E48
Replace inverter PCB or
NO
outdoor fan motor
Check it as much as
possible under the
operating conditions for
30 minutes before error
occurred
NO Wait and see.
Continue to obain data, if
possible
(Keep connecting the
Mente PC)
Replace compressor that is
NO
failed to startup
Replace power transistor
module
NO
Replace inverter PCB
Replace power transistor
module.
Refer Page 46.
NO
(Remove the power cable from
compressor and check the
resistance between P-U,
P-V, P-W, N-U, N-V, N-W
respectively.
Replace inverter PCB
YES