Mitsubishi Electric PURY-M200YNW-A1 Service Handbook page 278

[8-3 Refrigerant Control Problems ]
Cause
3. RPM error of the outdoor unit FAN
Motor failure or board failure, or airflow rate de-
crease due to clogging of the heat exchanger
The fan is not properly controlled as the outdoor
temperature cannot be precisely detected by the
temperature sensor.
The fan is not properly controlled as the pres-
sure cannot be precisely detected by the pres-
sure sensor.
4. Long piping length
The cooling capacity varies greatly depending on
the pressure loss. (When the pressure loss is
large, the cooling capacity drops.)
5. Piping size is not proper (thin)
6. Insufficient refrigerant amount
Protection works and compressor frequency does
not rise due to high discharge temperature.
7. Clogging by foreign object
8. The indoor unit inlet temperature is excessively
low. (Less than 15°C [59°F] WB)
9. Compressor failure
The amount of circulating refrigerant decreases
due to refrigerant leak in the compressor.
10. HBC LEV3 actuation failure
Sufficient cold water is not supplied as sufficient
sub cool cannot be secured on the HBC due to
LEV1, 2, and 3 actuation failure.
11. TH12, TH15 and 63HS1 sensor failure or faulty
wiring
LEV3 is not controlled normally.
12. HBC valve block actuation failure Sufficient cold
water is not supplied because of the insufficient
water flow rate and coexistence of cold and hot
water on the HBC due to valve block actuation fail-
ure.
13 Open phase in the power-supply due to improper
power-supply wiring
14 LEV4 failure
BS_08_L
Check method and remedy
Refer to the following page(s).
[8-7 Troubleshooting Outdoor Unit Fan Problems]
[7-3-3 Error Code [1302] (during operation)]
Check the piping length to determine if it is contributing to
performance loss.
Piping pressure loss can be estimated from the temperature
difference between the indoor unit heat exchanger outlet
temperature and the saturation temperature (Te) of 63LS.
->Correct the piping.
Refer to item 1 (Compressor frequency does not rise suffi-
ciently.) on the previous page.
Refer to the following page(s). [6-3 Evaluating and Adjusting
Refrigerant Charge]
Check the temperature difference between in front of and
behind the place where the foreign object is clogging the
pipe (upstream side and downstream side). When the tem-
perature drops significantly, the foreign object may clog the
pipe.
-> Remove the foreign object inside the pipe.
Check the inlet air temperature and for short cycling.
Change the environment where the indoor unit is used.
Check the discharge temperature to determine if the refrig-
erant leaks, as it rises if there is a leak.
Refer to the following page(s). [8-8-2 General Overview on
LEV Operation (HBC)]
Check the thermistor.
Check wiring.
Refer to the following page(s). [8-14 HBC Maintenance In-
structions (Applicable to main and sub HBCs)]
Make sure that the power-supply wiring is properly connect-
ed. (Refer to item (6) in section [6-1 Read before Test Run].)
Possible open phase.
Refer to the following page(s). [8-8-3 Possible Problems and
Solutions]
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