Troubleshooting By Inferior Phenomena - Mitsubishi Electric PUHZ-SW40VHA Service Manual

10-5. TROUBLESHOOTING BY INFERIOR PHENOMENA

Phenomena
1. Remote controller display does not
work.
2. "PLEASE WAIT" 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 heard
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 cool-
ing operation, however, the capacity
cannot be fully obtained. (The air
does not cool well.)
OCH525
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.
• "PLEASE WAIT" is not displayed.
• "PLEASE WAIT" is displayed.
1At longest 2 minutes after the power supply "PLEASE
WAIT" 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 mismatched.
1No operation for 2 minutes at most after the power
supply ON.
2Local remote controller operation is prohibited.
• Remote controlling adaptor is connected to CN32
on the indoor controller board.
• Local remote controller operation is prohibited
by centralised controller etc. since it is connected to
MELANS.
3Phenomena of No.2.
1Refrigerant shortage
2Filter clogging
3Heat exchanger clogging
4Air duct short cycle
25
Countermeasure
1 Check 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 phenomena No.3 below.
2 Check the following.
• Failure of remote controller if "PLEASE
WAIT" is not displayed
• Refer to phenomena No.2 below if
"PLEASE WAIT" is displayed.
1 Normal operation
2 Self-diagnosis of remote controller
3 "PLEASE WAIT" is displayed for 6 min-
utes at most in case of indoor/outdoor
unit communication error. Check LED3 on
indoor controller board.
(1) When LED3 is not blinking.
Check indoor/outdoor connecting wire
for miswiring.
(Converse wiring of S1 and S2, or
break of S3 wiring.)
(2) When LED3 is blinking.
Indoor/outdoor connecting wire is
normal.
4 Check LED display on outdoor controller
circuit board. Refer to 10-9.
Check protection device connector (63H)
for contact failure.
Refer to 10-9.
1 Normal operation
1Check the pair number settings.
1Normal operation
2Normal operation
3Check the phenomena No.2.
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 intake grille 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 blockage.