Fujitsu AOHG07KGCA, Service Manual

Page: 120 / 147

7-9. External electrical heater control
The external electrical heater is operated as below.
When the room
temperature rises
When the room
temperature drops
Ts: Setting temperature
Heater : Off
Heater : On
Heater : Off
Ts -10 ° C
Ts -1 ° C
Ts -3 ° C
Ts -12 ° C
NOTES:
• →hen the compressor stop, external electric heater is off.
• It operates only in heating mode and when the indoor fan operates. (However, S-LO→ is exclud-
ed.)
7-10. 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 Pulse range
Cooling/dry mode
Between 52 and 480 pulses
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).
7-11. Prevention to restart for 3 minutes (3 minutes st)
→hen the compressor fails to start for the number of times below, it does not enter operation status
for 3 minutes.
Retry number 50
Retry set number 3
→hen the compressor fails to start in the retry set number above, the compressor is stopped.
7-12. 4-way valve control
• If heating mode is selected at the compressor start, 4-way valve is energized for heating.
• →hen the air conditioner is switched between cooling and heating mode, compressor is stopped,
and the 4-way valve is switched when the 140 seconds passes and the compressor is started.
7-9. External electrical heater control
- (04-28) -
7. Various control
C
O
N
TR
O
L
A
N
D
FU
N
C
TI
O
N
S
C
O
N
TR
O
L
A
N
D
FU
N
C
TI
O
N
S