Auto Changeover Operation - Fujitsu AB F18LAT Series Service Instruction

1-4. AUTO CHANGEOVER OPERATION

When the air conditioner is set to the AUTO mode by remote control, operation starts in the optimum
mode from among the HEATING, COOLING, DRY and MONITORING modes. During operation,
the optimum mode is automatically swiched in accordance with temperature changes.
The temperature can be set between 18°C and 30°C in 1 degC steps.
When operation starts, only the indoor and outdoor fans are operated for 1 minute.
1
After 1 minute, the room temperature and outdoor air temperature are sensed and
the operation mode is selected in accordance with the table below.
( Fig.5 : Outdoor air temperature zone selection )
C zone
32°C
B zone
-10°C
A zone
( Table 4 : Operation mode selection table )
Outdoor temperature :To
Room temperature :Tb
Tb > Ts +2 degC
Ts +2 degC > Tb > Ts-2 degC
=
Ts +2 degC > Tb
Ts : Setting temperature
2 When COOLING was selected at
The same operation as COOLING OPERATION of item 5-1 above is performed.
However, the setting temperature is raised
When the compressor frequency have been below 20Hz for 8 minutes or the room temperature reaches
"setting temperature -1.5°C" , operation is automatically switched to DRY OPERATION of item 5-3 above
is performed.
However, compressor control based on room temperature is as follows.
Room
temperature
Ts -1.5°C
If the room temperature reaches "setting temperature +2°C" during DRY operation,
operation returns to COOLING operation.
When HEATING was selected at
3
above is performed. However, the room temperature correct coefficient value is 0°C.
When the compressor was stopped for 6 consecutive minutes by the temperature control function
4
after the COOLING or HEATING operation mode was selected at
to MONITORING and the operation mode is selected again.
A zone
Monitoring
Monitoring
=
Heating
, the air conditioner operates as follow:
1
Compressor :ON
Compressor :OFF
, the same operation as HEATING OPERATION of item 5-2
1
B zone
Cooling
(Automatic Dry)
Monitoring
Heating
1degC and the room temperature correct coefficient value is 0°C
Ts -0.5°C
1
01-04
C zone
Cooling
(Automatic Dry)
Monitoring
Monitoring
above, operation is switched