Mitsubishi Electric SUZ-KA24NAHZ Service Manual page 40

Phenomena
4. Even controlling by the IR wireless
remote controller no beep is heard
and the unit does not start operat-
ing. Operation display is indicated
on the IR wireless remote controller.
5. When operating by the IR 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.)
7. Remote controller display works nor-
mally and the unit performs heating
operation, however, the capacity
cannot be fully obtained.
8. 1For 3 minutes after temperature
adjuster turns off, the compressor
will not start operating even if
temperature adjuster is turned on.
2For 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.)
OCH754A
Factor
1 The pair number settings of the IR wireless remote
controller and indoor controller board are mismatched.
1 No operation for 2 minutes at most after the power
supply ON.
2 Hand-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 centralized controller etc. since it is connected to
MELANS.
3 Refer to factor of No.2 on previous page.
1 Refrigerant shortage
2 Filter clogging
3 Heat exchanger clogging
4 Air duct short cycle
1 Linear expansion valve fault
Opening cannot be adjusted well due to linear expan-
sion valve fault.
2 Refrigerant shortage
3 Lack of insulation for refrigerant piping
4 Filter clogging
5 Heat exchanger clogging
6 Air duct short cycle
7 Bypass circuit of outdoor unit fault
12 Normal operation
(For protection of compressor)
1 Check the pair number settings.
1 Normal operation
2 Normal operation
3 Check phenomena of No.2.
1 If refrigerant leaks, discharge temperature
rises and LEV opening increases.
Inspect leakage by checking the tempera-
ture and opening.
Check pipe connections for gas leakage.
2 Open intake grille and check the filter.
Clean the filter by removing dirt or dust
on it.
3 If the filter is clogged, indoor pipe tempera-
ture rises and discharging pressure increas-
es. Check if heat exchanger is clogged by
inspecting discharging pressure.
Clean the heat exchanger.
4 Remove the shield.
1 Discharge temperature and indoor heat
exchanger temperature does not rise.
Inspect the failure by checking discharge
pressure.
Replace linear expansion valve.
2 If refrigerant leaks, discharge temperature
rises and LEV opening increases.
Inspect leakage by checking the tempera-
ture and opening.
Check pipe connections for gas leakage.
3 Check the insulation.
4 Open intake grill and check the filter.
Clean the filter by removing dirt or dust
on it.
5 If the filter is clogged, indoor pipe tempera-
ture rises and discharge pressure increas-
es. Check if heat exchanger is clogged by
inspecting discharge pressure.
Clean the heat exchanger.
6 Remove the shield.
7 Check refrigerant system during operation.
12 Normal operation
40
Countermeasure