Troubleshooting By Inferior Phenomena - Mitsubishi Electric PUHZ-RP3VHA Technical & Service Manual

10-5. TROUBLESHOOTING BY INFERIOR PHENOMENA

Phenomena
1. Remote controller display does not
work.
2. "HO" display is remained on the
remote controller.
3. When pressing the remote controller
operation switch the OPERATION
display is appeared but it will be
turned off soon.
4. Even controlling by the wireless
remote controller no beep is heared
and the unit does not start operat-
ing. Operation display is indicated
on wireless remote controller.
5. When operating by the wireless
remote controller, beep sound is
heard, however, unit does not start
operating.
6. Remote controller display works
normally and the unit performs
cooling operation, however, the
capacity cannot be fully obtained.
(The air does not cool well.)
Factor
1DC12V is not supplied to remote controller.
(Power supply display is not indicated on LCD.)
2DC12~15V is supplied to remote controller, however,
no display is indicated.
• "HO" is not displayed.
• "HO" is displayed.
1At longest 2 minutes after the power supply "H0" is
displayed to start up.
2Communication error between the remote controller
and indoor unit
3Communication error between the indoor and outdoor
unit
4Outdoor unit protection device connector is open.
1After cancelling to select function from the remote
controller, the remote controller operation switch will
be not accepted for approx 30 seconds.
1The pair number settings of the wireless remote
controller and indoor controller board are mis-
matched.
1No operation for 2 minutes at most after the power
supply ON.
2Hand-held remote controller operation is prohibited.
• Remote controlling adaptor is connected to CN32
on the indoor controller board.
• Hand-held remote controller operation is prohibited
by centralised controller etc. since it is connected to
MELANS.
3Factor of No.2 above.
1Refrigerant shortage
2Filter clogging
3Heat exchanger clogging
4Air duct short cycle
37
Countermeasure
1Check LED2 on indoor controller board.
(1) When LED2 is lit.
Check the remote controller wiring for
breaking or contact failure.
(2) When LED2 is blinking.
Check short circuit of remote controller
wiring.
(3) When LED2 is not lit.
Refer to No.3 below.
2Check the following.
• Failure of remote controller if "HO" is not
displayed
• Refer to No.2 below if "HO" is displayed.
1Normal operation
2Self-diagnosis of remote controller
3"HO" is displayed for 6 minutes at most. in
case of indoor/outdoor unit communica-
tion error. Check LED3 on indoor con-
troller board.
(1)When LED3 is not blinking.
Check indoor/outdoor connecting wire
for mis-wiring.
(Converse wiring of S1 and S2, or
break of S3 wiring.)
(2)When LED3 is blinking.
Indoor/outdoor connecting wire is nor-
mal.
4Check LED display on outdoor controller
board.
Check protection device connector (63L
and 63H) for contact failure.
1Normal operation
1Check the pair number settings.
1Normal operation
2Normal operation
3Check the details of No.2 above.
1• If refrigerant leaks, discharging tempera-
ture rises and LEV opening increases.
Inspect leakage by checking the tem-
perature and opening.
• Check pipe connections for gas leakage.
2Open suction grill and check the filter.
Clean the filter by removing dirt or dust on
it.
3• If the filter is clogged, indoor pipe tem-
perature rises and discharging pressure
increases. Check if heat exchanger is
clogged by inspecting discharging pres
sure.
• Clean the heat exchanger.
4Remove the shield.