Fujitsu AB* A12GATH, Service Manual

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3-4-2 ELECTRONIC EXPANSION VALVE CONTROL for Outdoor air unit
03-14
1. Initialization
When starting up
3. Special Control
Oil recovery operation : Controlled pulse(Maximum 1400 puls)
Test run operation : Controlled pulse.
Freeze prevention control : Fully closed.
Vacuuming operation : Fully open.
Defrost operation : Controlled pulse(Maximum 1400 puls)
When indoor unit stopping by Thermo-OFF condition.
When the power is turned ON.
When it has passed the limited time since the last initialization.
The discharge airflow temperature is controlled so that it reaches to the set-up temperature based on the difference
between the discharge airflow temperature and the set-up temperature.
Cooling operation: 1) If the discharge airflow temperature becomes 5°C lower than the set-up temperature,
EEV is fully closed.
2) If the suction airflow temperature becomes 0.5°C lower than the set-up temperature,
EEV is fully closed.
Heating operation: 1) If the discharge airflow temperature becomes 5°C higher than the set-up temperature
for 5 minutes or more, EEV is fully closed.
2) If the suction airflow temperature becomes 0.5°C higher than the set-up temperature,
EEV is fully closed.
Discharge airflow temperature control
Automatic PI control is performed based on the indoor unit heat exchanger outlet temp and inlet temp.
Automatic operatic control
2. Operation Control
Fully closed OFF
(Cooling) Move to the cooling control base pulse in steps.
(Heating) Move to the heating control base pulse in steps.
Fully closed
Fully closed
Heating
Cooling
EEV Condition
Outdoor unit Condition