Mitsubishi Heavy Industries V Multi FDC71VNX Technical Manual page 343

(l) Dewing prevention control
[Control condition]
During cooling and dehumidifying operation, if all the following conditions are established, the compressor speed
(frequency) is reduced to prevent dewing and water splash.
(i) Cooling electronic expansion valve aperture (EEVC) is 500 pulses.
(ii) Suction overheat is 10°C or higher.
(iii) Compressor speed (frequency) is A rps or higher.
[Control contents]
(i) When the suction overheat is 10°C or higher, the compressor speed (frequency) is
reduced at each 1 minute.
(ii) Compressor speed (frequency) does not rise till the cooling
expansion valve becomes 460 pulses.
(iii) This control takes A rps as its lower limit so that compressor
speed is not controlled when it is less than A rps.
(m) Refrigerant quantity shortage protection
Under the compressor protection start III control during cooling and dehumidifying operations, the following control is
performed by detecting the indoor heat exchanger temperature (Thi-R) and the indoor return air temperature (Thi-A).
[Control condition]
When the state that the indoor heat exchanger temperature (Thi-R) does not become lower than the indoor return air
temperature (Thi-A) by 4°C or more continues for 1 minute.
[Control contents]
It judges that the flowing of refrigerant in to the indoor unit is insufficient so that the compressor is stopped and E57 is
displayed on the remote control.
(n) Broken wire detection on temperature sensor and low pressure sensor
(i) Outdoor heat exchanger temperature sensor, outdoor air temperature sensor and low pressure sensor
If the following is detected for 5 second continuously within 2 minutes to 2 minutes and 20 seconds after the
compressor ON, the compressor stops. After a delay of 3 minutes, it restarts but, if the same is detected repeatedly 3
times within 40 minutes, the compressor stops with the anomalous stop.
Note (1) During defrost operation and for 3 minutes after the end of defrost operation, it is not detected.
• Outdoor heat exchanger temperature sensor: -50°C or lower
• Outdoor air temperature sensor: -45°C or lower
• Low pressure sensor: 0V or under or 4.0V or over
(ii) Discharge pipe temperature sensor, suction pipe temperature sensor, compressor under dome temperature sensor
If the following is detected for 5 seconds continuously within 10 minutes to 10 minutes and 20 seconds after the
compressor ON, the compressor stops. After a delay of 3 minutes, it restarts but, if the same is detected repeatedly 3
times within 40 minutes, the compressor stops with the anomalous stop.
Note (1) During defrost operation and for 3 minutes after the end of defrost operation, it is not detected.
• Discharge pipe temperature sensor: -10°C or lower
• Suction pipe temperature sensor: -50°C or lower
• Compressor under dome temperature sensor : -50°C or lower
(o) Fan motor error
(i) If the fan speed of 100min
operation command of fan tap at
(ii) When the fan motor speed drops to 100min
the anomalous stop mode with E48 displayed on the remote control.
(p) Anomalous stop by the compressor start stop
(i) When it fails to shift to the compressor DC motor's rotor position defection operation at 5 seconds after establishing
the compressor start condition, the compressor stops temporarily and restarts 3-minute later.
(ii) If it fails to shift to the position detection operation again 20 times, it judges the anomalous compressor start and
stops the compressor by the anomalous stop (E59).
or under is detected for 30 seconds continuously under the outdoor fan control (with the
- 1
speed or higher), the compressor stops.
①
or under 5 times within 60 minutes and the compressor stops, it enters
- 1
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'19 • PAC-T-327
Model A rps
FDC200 60
FDC250 60