Fujitsu AirStage AB12, Service Manual

Page: 74 / 199

After the power is turned on, the following operation is controlled automatically to control the most suitable refrigerant
charge according to the operation mode and operation conditions of each unit.
Electronic expansion valve control process.
The electronic expansion valve adjusts the opening by selecting the number of pulses from the rated capacity,operation
mode ( cool / heat ) and set temperature of each indoor unit.
(1) The air conditioner restarts with the previous setting operation.
(2) When the air conditioner restarts, the " THREE MINUTE DELAY FUNCTION " operates.
(3) When the air conditioner restarts for heating operation, the " COLD AIR DISCHARGE PREVENTION FUNCTION "
operates.
(4) When the timer power is interrupted during operation and is reset later, the timer display flashes ( on 3 sec. / off 1 sec.).
(1) When refrigerant circulation starts, the drain pump starts simultaneously.
(2) The drain pump operates continuously for 3 minutes after the refrigerant circulation stopped.
(3) When the refrigerant circulation stops by the 'Indoor heat exchanger de-icing function', the drain pump is turned off
in 1 hour after the compressor stops.
(4) When the water level in the drain pan rises up and then the float switch functions:
Microcomputer stops the refrigerant circulation and indoor and outdoor fan motor operation.
Drain pump operates continuously for 3 minutes after the float switch is turned off.
(Almost condensing water may be drained)
(5) When the float switch turns ON continuously for 3 min., 'FAILURE INDICATION' operates.
(6) When the float switch turns OFF within 3 min., the unit starts cooling operation.
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2
6-7 DRAIN PUMP OPERATION
6-6 AUTO RESTART
6-5 ELECTRONIC EXPANSION VALVE CONTROL
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