Mitsubishi Electric CAHV-R450YA-HPB Service Manual page 166

[ X Troubleshooting ]
Outdoor Unit F an
-7- Fan
The rotation speed of the fan is controlled by the inverter. Check the inverter output status on the LED to check the rotation
speed. The maximum rotation speed of the fan is approximately 780 rpm. Make appropriate settings on the display function
to get the output to be displayed [%]. Refer to section 2. "Checking the sensor status" for how to use the display function
(page 129). 78% indicates that the fan is operating at full speed, and 0% indicates that the fan is stopped.
The rotation speed of the fan changes according to the number of units in operation. If the fan does not operate or if it vibrates,
FAN INV board problem or fan motor error is suspected. Refer to section -5-(2) [5] "Check the fan motor ground fault or the
winding." (page 151) and section [6] "Check the fan inverter board failure." (page 151)
-8- Troubleshooting
1. Important notes
If the unit or its refrigerant circuit components experience malfunctions, take the following steps to prevent recurrence.
(1) Diagnose the problem and find the cause.
(2) Before repairing leaks on the brazed sections on the pipes, recover the refrigerant. Braze under nitrogen purge to prevent
oxidation.
(3) If any component (including the compressor) malfunctions, only replace the affected parts; it is not necessary to replace
the entire unit.
(4) Be sure to recover the refrigerant from the unit before disposing of the unit.
(5) If the cause of the problem cannot be identified, contact the service desk with the following information: unit model, serial
number, and the nature of the problem.
2. Before replacing the fan
(1) Before replacing the fan, turn off the main power of the unit.
(2) The motor connectors are on the FAN INV board in the control box and can be accessed by removing the service panel.
(3) Install the fan wires as they were, using the same route and all required clamps.
HWE22020
A
198 ~ 264 VAC
NO
Check the voltage between L3 and N at the power supply
terminal block TB1.
198 ~ 264 VAC
NO
B
Replace the M-NET board
YES
Replace the noise filter.
YES
Replace the noise filter.
Check and fix any power supply wiring and main power
supply problems found.
- 157 -
C
Turn on the
power again.
GB