Mitsubishi Electric PUHZ-RP250YHA2 Service Manual page 39

Phenomena
4. Even controlled 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 is
not cool enough.)
7. Remote controller display works
normally and the unit performs heat-
ing operation, however, the capacity
cannot be fully obtained.
8. For 3 minutes after temperature
adjuster turns off, the compressor
will not start operating even if
temperature adjuster is turned on.
For 3 minutes after temperature
adjuster turns on, the compressor
will not stop operating even if
temperature adjuster is turned off.
(Compressor stops operating
immediately when turning off by
the remote controller.)
Factor
The pair number settings of the wireless remote con-
troller and indoor controller board are mismatched.
No operation for 2 minutes at most after the power
supply ON.
Local 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.
Phenomena of No.2.
Refrigerant shortage
Filter clogging
Heat exchanger clogging
Air duct short cycle
Linear expansion valve fault
Opening cannot be adjusted well due to linear expan-
sion valve fault.
Refrigerant shortage
Lack of insulation for refrigerant piping
Filter clogging
Heat exchanger clogging
Air duct short cycle
Bypass circuit of outdoor unit fault
Normal operation
(For protection of compressor)
39
Countermeasure
Check the pair number settings.
Normal operation
Check the phenomena of No.2.
• 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.
Open suction grille and check the filter.
Clean the filter by removing dirt or dust on
it.
• If the filter is clogged, indoor pipe tem-
perature rises and discharging pressure
increases. Check if heat exchanger is
clogged by inspecting discharging
pressure.
• Clean the heat exchanger.
Remove the shield.
• Discharging temperature and indoor
heat exchanger temperature does not
rise.
Inspect the failure by checking discharg
ing pressure.
• Replace linear expansion valve.
• If refrigerant leaks, discharging tempera-
ture rises and LEV opening increases.
Inspect leakage by checking the tempera-
ture and opening.
• Check pipe connections for gas leak-
age.
Check the insulation.
Open suction grille and check the filter.
Clean the filter by removing dirt or dust
on it.
• 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.
Remove the shield.
Check refrigerant system during opera-
tion.
Normal operation