AirStage ARXB07LALH, Service Manual

Page: 53 / 207

3-4 ELECTRONIC EXPANSION VALVE CONTROL
03-09
3-5 DRAIN PUMP OPERATION
1. Initialization
2. Operation Control
When starting up
Automatic operatic control
Automatic PI control is performed based on the indoor unit heat exchanger outlet temp and inlet temp.
Room temperature control
The room temperature is controlled so that it reaches to the set-up temperature based on the difference
between the room temperature and the set-up temperature, and the change of indoor unit temperature.
if the room temperature becomes 0.5 C lower than the set-up temperature, EEV is fully closed.
3. Special Control
(1) When cooling and 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 refrigent circulation is stopped by a start of indoor heat exchanger frost prevention
operation, the drain pump will turn off in 1 hour after the end of indoor heat exchanger frost
prevention operation.
(4) When the water level in the drain pan rises up and then the float switch functions:
Microcomputer stops the refrigerant circulation and indoor 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 minutes, 'FAILURE INDICATION' operates.
(6) When the float switch turns OFF within 3 minutes, the unit starts cooling operation.
1
2
When the power is turned ON.
When it has passed the limited time since the last initialization.
When indoor unit stopping
Oil recovery operation : Controlled pulse.
Test run operation : Controlled pulse.
Icing protection control : Fully closed.
Pump down operation : Fully open.
Defrost operation : Controlled pulse
Outdoor unit Condition
EEV Condition
Cooling
Heating
Fully closed
Slightly open
(Cooling) Move to the cooling control base pulse in steps.
(Heating) Move to the heating control base pulse in steps.
OFF Fully closed