Fujitsu AUUH18LUAS Service Manual page 212

 Heat pump prohibition control
Perform heating by external heater only. Indoor unit is continuous thermostat off.
Operation
Heater on
Heater off
• Temperature of heater on (Thon): Adjustable by function number 62 (Operating temperature
switching of external heaters).
• All control temperatures will shift by adjusting "Thon".
Tr-Ts ≥ 0.9°F
(0.5°C)
• Operation status
Heating operation
Room temperature
Comp. On/Off
Heater
Fan
NOTE: In following operations, compressor will be on.
• Other than heating
• Test run
3-5. Details of control output function
Heater is on as shown in following diagram of heating temperature.
• Heater is off as shown in following diagram of heating temperature.
• Other than heating mode
• Error occurred
• Forced thermostat off
Tr-Ts
Off
Tr-Ts (=Thon) ≤ -0.9°F (-0.5°C)
On
On
Off
0.9°F (0.5°C)
Set temp.
-0.9°F (-0.5°C)
On
Off
12 V
0 V
On
Off
Condition
Tr: Room temperature
Ts: Set temperature
Thon: Heater on temperature
3 min or more
- (05-30) -
3. External input and output (for indoor unit)