Fujitsu ASU30RLE Service Instruction page 119

 Heater selection control by outdoor temperature 2
Operation
Heater on 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
Heater off
• Error occurred
• Forced thermostat 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 by function setting no. 36 for outdoor
unit.
• External heater output
Tr-Ts ≥ 0.9°F
(0.5°C)
• Outdoor temperature zone
A + 3.6°F ( 2°C): -0.4°F (-18°C)
• Operation status
Outdoor temperature
(Factory setting)
Outdoor temperature zone *
Comp. On/Off
Heater
Fan
* 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
Tr-Ts
Off
Tr-Ts (=Thon) ≤ -0.9°F
(-0.5°C)
On
Outdoor temp.
*A: -4°F (-20°C)
*Adjustable by function setting no. 66.
46.4°F (8°C)
42.8°F (6°C)
-0.4°F (-18°C)
-4°F (-20°C)
Heat pump
prohibition
zone
On
Off
12 V
0 V
On
Off
03-29
Condition
Tr: Room temperature
Ts: Set temperature
Thon: Heater on temperature
Combination zone
(Heat pump + Heater)
Heat pump prohibition zone
(Heater)
Combination zone