Silent Mode; Test Run; Pump-Down Control - Mitsubishi Heavy Industries V Multi FDC71VNX Technical Manual

(7) Silent mode

(a) As "Silent mode start" signal is received from the remote control, it operates by dropping the outdoor 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 control PCB.
ON
SW3-3
OFF
Make sure to turn SW3-3 to OFF after the end of operation.
(b) Test run control
(i) Operation is performed at the maximum compressor speed (frequency), which is determined for each model.
(ii) Each protective control and error detection control are effective.
(iii) If SW3-4 is switched during test run, the compressor is stopped once by the stop control and the cooling/heating op-
eration is switched.
(iv) Setting and display of remote control during test run
Mode
Cooling test run
Heating test run

(9) Pump-down control

Turning ON the pump-down switch SW1 for 2 seconds during the operation stop or anomalous stop (excluding the
thermostat OFF), the pump-down operation is performed. (This is invalid when the indoor unit is operating. This is
effective even when the indoor unit is stopped by the anomalous stop or the power source is turned OFF.)
(a) Control contents
(i) Close the service valve at the liquid side. (It is left open at the gas side.)
(ii) Compressor is started with the target speed (frequency) at FDC200:45, FDC250:55 rps in the cooling mode.
(iii) Red and green lamps (LED) keeps flashing on the outdoor control PCB.
(iv) Each of protection and error detection controls, excluding the low pressure control, anti-frost control and dewing
prevention control, is effective.
(v) Outdoor unit fan is controlled as usual.
(vi) Electronic expansion valve is fully opened.
(b) Control ending conditions
Stop control is initiated depending on any of the following conditions.
(i) Low pressure of 0.087MPa or lower is detected for 5 seconds continuously.
1) Red LED: Light, Green LED: keeps flashing, Remote control: Displays stop.
2) It is possible to restart when the low pressure is 0.087MPa or higher.
3) Electronic expansion valve (cooling/heating) is kept fully open.
(ii) Stop by the error detection control
1) Red LED: keeps flashing, Green LED: keeps flashing
2) Restart is prohibited. To return to normal operation, reset the power source.
3) Electronic expansion valve (cooling/heating) is left fully open.
(iii) When the cumulative operation time of compressor under the pump-down control becomes 5 minutes.
1) Red LED: stays OFF, Green LED: keeps flashing, Remote control: Stop
2) It is possible to pump-down again.
3) Electronic expansion valve (cooling/heating) is left fully open.
Note (1) After the stop of compressor, close the service valve at the gas side.
Caution: Since pressing the pump-down switch cancels communications with the indoor unit, the indoor unit and the remote
control display "Transmission error – E5". This is normal.
OFF
SW3-4
ON
Normal and end of test run
Item
Contents of remote control setting/display
Setting temperature of cooling is 5°C.
Setting temperature of heating (preparation) is 30°C.
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Cooling test run
Heating test run
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'19 • PAC-T-327