Fujitsu AOU42RGLX Design & Technical Manual page 64

 Heater selection 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 setting no. 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 no. 66
and 67 for outdoor unit.
• External heater output
Tr-Ts ≥ 0.9°F
(0.5°C)
• Outdoor temperature zone
• Operation status
Outdoor temperature
Outdoor temperature zone *
* The outdoor temperature zone transition from one to another will stay in that zone for minimum of 30 min.
NOTE: In following operations, compressor will be on in heat pump prohibition zone.
• Other than heating
• Test run
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) ≤ -0.9°F
On
Outdoor temp.
B + 3.6°F (2°C): 46.4°F (8°C)
*B: 42.8°F (6°C)
A + 3.6°F ( 2°C): -0.4°F (-18°C)
*A: -4°F (-20°C)
46.4°F (8°C)
42.8°F (6°C)
(Factory setting)
-0.4°F (-18°C)
-4°F (-20°C)
On
Comp. On/Off
Off
12 V
Heater
0 V
On
Fan
Off
Condition
Tr: Room temperature
Ts: Set temperature
(-0.5°C)
Thon: Heater on temperature
Heat pump only zone
(Heat pump)
Combination zone
(Heat pump + Heater)
Heat pump prohibition zone
(Heater)
*Adjustable by function setting no. 66 and 67
Heat pump
Combination zone
prohibition
zone
- 58 -
Heat pump
only zone
8. External input and output