Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 932

FDC-HKX
(ii) When the compressor does not operate although the remote controller display is normal (Without the
check display)
Take following steps first before confirming the following items:
• Confirm that it is normal at the indoor unit side, LED1 (green) keeps flashing on the outdoor unit control PCB and LED2
(red) is not lit.
• When LED1 (red) is flashing while the remote controller display is normal, LED2 (red) can be turned off if SW
ON and turned OFF again.
Note (1) Be sure to turn the SW
Turn on SW (test run) on the outdoor
3-5
contorol PCB.
(Refer to page 819)
Is 52C turned ON?
YES
(1)
Does compressor
operate?
1
NO
(From next page)
Does LED1 (green) on
inverter PCB flash?
YES
Do 7 SEG on out-
door unit PCB indicate
20Hz or higher?
YES
Is voltage detected
between U,V,W on
power transistor?
NO
Defective inverter
Notes (1) Expansion valve of the indoor unit may be closed or the indoor fan may be stopped. Stop the compressor no sooner than it has started. Neglecting
this caution could result in compressor trouble.
(2) Method to check with the outdoor unit only is described on the next page.
930
off after the confirmation.
3-5
• It is designed to transmit the highest request frequency from the
outdoor to the indoor regardless the state of thermostat. It will not
operate therefore if the transmission is not normal between the
outdoor and the indoor.
When it is turned on with SW
•
unless the indoor unit is connected. In such occasion, operate the
system with the remote controller and check if E3 (no counterpart)
or E5 (transmission error) is transmitted or not.
NO
Is voltage detected on
52C coil?
NO
Outdoor unit control
PCB is defective.
YES
• Is indoor return air thermistor normal?
• Is thermostat stopped?
NO
Defective inverter
(See page 933.)
NO
Note(1) Set 7 SEG indicator changeover
swich (SW ) to 0.
4
YES
Defective compressor
(test run), there is no error display
3-5
YES
Replace 52C.
Does LED2 (red) on
YES
inverter PCB light
or flash?
NO
Check error display again.
is turned
3-1
Diagnose errors on
LED's on inverter
PCB.