Fujitsu ASTG09KMTC Design & Technical Manual page 30

 Auxiliary heater control by outdoor temperature 1
This control selects heat pump or external heater according to the outdoor temperature. When out-
door temperature is high, the heating is performed by using heat pump only.
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".
• Outdoor temperature zone boundary A and B: Adjustable individually by function setting number
66 and 67.
• External heater output
Tr-Ts ≥ 0.5°C
• Outdoor temperature zone
*: Adjustable by function setting 66 and 67
8-4. Details of 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
• Heat pump only zone
Tr-Ts
Off
Tr-Ts (=Thon) ≤ -0.5°C
On
Outdoor temp.
Heat pump only zone
B + 2°C: 8°C
B: 6°C*
Combination zone
(Heat pump + Heater)
A + 2°C: -18°C
A: -20°C*
Heat pump prohibition zone
Condition
Tr: Room temperature
Ts: Set temperature
Thon: Heater on temperature
(Heat pump)
(Heater)
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8. External input and output