Fujitsu AUUH18LUAS Service Manual page 224

 Auxiliary heat pump control by outdoor temperature 3
• External heater output
Operation
Heater on
Heater off
– Temperature of heater on (Thon): Set temperature (Ts) -0.9°F (-0.5°C)
– Temperature of heater off: Set temperature (Ts) +0.9°F (+0.5°C)
Tr-Ts ≥ 0.9°F
(0.5°C)
• Auxiliary heat pump On/Off
– Temperature of heat pump on (Thon): Adjustable by function number 62 (Operating temperature
switching of heat pump).
– All control temperatures will shift by adjusting "Thon".
Tr-Ts ≥ 0.9°F
(0.5°C)
*: →hen room temperature stays in this zone for a specific time, auxiliary heater is turned on. For
details, refer to function number 71.
• Outdoor temperature zone
B + 3.6°F (2°C): 46.4°F (8°C)
A + 3.6°F (2°C): -0.4°F (-18°C)
*: Adjustable by function setting 66 and 67
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
Tr-Ts
Off
Tr-Ts (=Thon) < -0.9°F (-0.5°C)
On
Outdoor temp.
Heater only zone
B: 42.8°F (6°C)*
Combination zone
(Heat pump + Heater)
A: -4°F (-20°C)*
Heater only zone
Condition
Tr: Room temperature
Ts: Set temperature
Thon: Heater on temperature
*
Tr: Room temperature
Ts: Set temperature
Thon: Heat pump on temperature
- (05-42) -
3. External input and output (for indoor unit)