SERVICE MANUAL - Mitsubishi Heavy Industries Ltd.
SERVICE MANUAL - Mitsubishi Heavy Industries Ltd.
SERVICE MANUAL - Mitsubishi Heavy Industries Ltd.
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S Only case of FDKN<br />
Only case of 151~251 types<br />
CNM<br />
1 and 3 (Red – Black)<br />
DC280V?<br />
CNM<br />
4 and 3 (White-Black)<br />
DC15V?<br />
YES<br />
Does the<br />
fan motor turn<br />
smoothly by<br />
hand?<br />
YES<br />
NO<br />
NO<br />
YES YES<br />
NO<br />
NO<br />
Replacement indoor<br />
unit control PCB<br />
Secondary<br />
side of transformer<br />
(red-red) 14V<br />
or more<br />
(2)<br />
Is the voltage<br />
at CNM 5 (Yellow) DC 1V<br />
YES<br />
or higher?<br />
Note (2) CNM 3 (Black) is GND.<br />
Replacement indoor<br />
unit control PCB<br />
Only case of 301 type<br />
CNM<br />
1 and 4 (Red-Blue)<br />
DC 0~60V ?<br />
NO<br />
Turn the power off and wait<br />
a short time (30 min. ~ 1 hr.)<br />
YES<br />
When tried again,<br />
the fan goes ON.<br />
YES<br />
Replacement indoor<br />
unit control PCB<br />
3 (Black) is GND.<br />
3 (Black) is GND.<br />
3 (black) is GND.<br />
YES<br />
YES<br />
NO<br />
Replacement transformer<br />
Detective fan motor<br />
Replacement fan<br />
motor<br />
Check the<br />
circumstances.<br />
- 19 -<br />
NO<br />
NO<br />
Abnormal data check<br />
with remote controller<br />
After check reset,<br />
fan runs on Me.<br />
Fan ON?<br />
YES<br />
Was it reproduced?<br />
YES<br />
YES<br />
NO<br />
Check the<br />
circumstances.<br />
When the (1)<br />
motor is turning, does<br />
the voltage at CNM 6 (Blue)<br />
fluctuate between<br />
DC 0 ~ 15 V?<br />
Note (1) CNM 3 (Black) is GND.<br />
Replacement indoor<br />
unit control PCB<br />
● Display conditions<br />
If an indoor unit fan motor’s speed is detected to be less than<br />
200 rpm continuously for 30 seconds, the fan motor stops for 2<br />
seconds. After 2 seconds, it starts again, but this occurs 4 times<br />
within a period of 1 hour.<br />
NO<br />
NO<br />
After check reset,<br />
fan runs on Me.<br />
Fan ON ?<br />
YES<br />
Was it reproduced?<br />
YES<br />
When (1)<br />
the motor is turning,<br />
does the voltage at CNM 5<br />
(White) fluctuate between<br />
DC 0 ~ 15 V?<br />
YES<br />
Replacement indoor<br />
unit control PCB<br />
NO<br />
NO<br />
Check the<br />
circumstances.<br />
Replacement fan<br />
motor<br />
Note (1) CNM 4 (Blue) is GND.<br />
● Display conditions<br />
If an indoor unit fan motor’s speed is detected to be less than<br />
200 rpm continuously for 30 seconds, the fan motor stops for 2<br />
seconds. After 2 seconds, it starts again, but this occurs 4 times<br />
within a period of 1 hour.
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