Compressor Preheating; External Electrical Heater Control; Electronic Expansion Valve Control - Fujitsu AO G09KATA Series Service Instruction

6-5. Compressor preheating

By preheating the compressor, warm airflow is quickly discharged when the operation is started.
• Triggering condition
– 30 minutes after compressor stopped.
– Outdoor unit heat exchanger temperature (Tn)
When the jumper wire (JM2) is disconnected:

6-6. External electrical heater control

The external electrical heater is operated as below.
Ts -3°C
Ts -12°C
When the room
temperature drops
NOTES:
• When the compressor stop, external electric heater is off.
• It operates only in heating mode and when the indoor fan operates. (However, S-LOW is exclud-
ed.)

6-7. Electronic expansion valve control

The most proper opening of the electronic expansion valve is calculated and controlled under the
present operating condition based on the table below.
Operation mode
Cooling/dry mode
Heating mode
NOTE: At the time of supplying the power to the outdoor unit, the initialization of the electronic ex-
pansion valve is operated (528 pulses are input to the closing direction).
6-5. Compressor preheating
Tn
Off
-2°C
On
Tn
Off
5°C
On
When the room
temperature rises
Heater : Off
Heater : On
Heater : Off
- (01-25) -
Tn
-4°C
Tn
7°C
Ts: Setting temperature
Ts -1°C
Ts -10°C
Pulse range
Between 52 and 480 pulses
6. Various control