Silent Mode - Mitsubishi Electric FDT125VNVF Technical Manual

(n) Broken wire detection on temperature thermistor and low pressure sensor
1) Outdoor unit heat exchanger thermistor, outdoor air thermistor 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 defrosting and for 3 minutes after the end of defrosting, it is not detected.
• Outdoor unit heat exchanger thermistor: -50°C or lower
• Outdoor air temperature thermistor: -45 or lower
• Low pressure sensor: 0V or under or 4.0V or over
2) Discharge pipe temperature thermistor, suction pipe temperature thermistor and underneath temperature thermistor
(model 200, 250 only)
If the following is detected for 5 second 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 defrosting and for 3 minutes after the end of defrosting, it is not detected.
• Discharge pipe temperature thermistor: -10°C or lower
• Suction pipe temperature thermistor: -50 or lower
• Underneath temperature thermistor: -50°C or lower
(o) Fan motor error
1) If the fan speed of 100rpm or under is detected for 30 second continuously under the outdoor unit fan control (with
the operation command of fan tap at ➀ speed or higher), the compressor stops.
2) When the fan motor speed drops to 100rpm or under 5 times within 60 minutes and the compressor stops, it enters
the anomalous stop mode with E48 displayed on the remote controller.
(p) Anomalous stop by the compressor start stop
1) 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 minutes later.
2) If it fails to shift to the position detection operation again at second time, it judges the anomalous compressor start
and stops the compressor by the anomalous stop (E59).
(q) Anomalous compressor rotor lock (model 200, 250 only)
After shifting to the compressor rotor's position detection operation, if fails again to detect the rotor position, the
compressor stops.
Compressor restarts 3 minutes later but, if it is operated 4 times within 15 minutes, the anomalous stop (E60) occurs.
(7)

Silent mode

(a) As "Silent mode start" signal is received from the remote controller, it operates by dropping the outdoor unit fan tap and
the compressor speed (frequency).
(b) For details, refer to items (1) and (4) above.
(8) Test run
(a) It is possible to operate from the outdoor unit using the dip switch on the outdoor unit control PCB.
ON
SW3-3
OFF
Make sure to turn SW3-3 to OFF after the end of operation.
(b) Test run control
1) Operation is performed at the maximum compressor speed (frequency), which is determined for each model.
2) Each protective control and error detection control are effective.
3) If SW3-4 is switched during test run, the compressor is stoped for once by the stop control and the cooling/heating
operation is switched.
4) Setting and display of remote controller during test run
Mode
Cooling test run
Heating test run
OFF
SW3-4
ON
Normal and end of test run
Item
Contents of remote controller setting/display
Setting temperature of cooling is 5°C.
Setting temperature of heating (preparation) is 30°C.
-
Cooling test run
Heating test run
325
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'12 • PAC-T-174