Design Technical Manual

Table Of Contents
AUXILIARY HEATER CONTROL BY OUTDOOR TEMPERATURE 3
Selects Heat pump or External heater according to the outdoor temperature. Even when outdoor
temperature is high, the heating is performed by using both of heat pump and external heater.
Operation Condition
Heater ON Heater ON as shown in diagram of heating temperature
Heater
OFF
DIP-SW2-3 ON
Indoor unit fan
setting for external
heater: Enable
Heater OFF as shown in diagram of heating temperature
Other than Heating mode
Error occurred
Forced thermostat off
Fan stop protection
DIP-SW2-3 OFF
Indoor unit fan
setting for external
heater: Disable
Heater OFF as shown in diagram of heating temperature
Other than Heating mode
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 individually by Function setting
No. 36 and 37 for outdoor unit.
External heater output
OFF
ON
Tr-Ts ≥ 0.F
(0.C)
Tr-Ts
Tr-Ts (=Thon) -0.9°F
(
-0.C)
Tr: Room temperature
Ts: Set temperature
Thon: Heater ON temperature
Outdoor temperature zone
Heat pump only zone
(Heat pump)
Combination zone
(Heat pump + Heater)
B + 3.6°F (2°C): 46.4°F (8°C)
Outdoor temp.
*Adjustable by Function setting
When room temperature stays in this zone for a specic time, auxiliary heater is turned on.
For details, refer to indoor unit function number 71 in Chapter. 7 "FUNCTION SETTING".
*B: 42.8°F (6°C)
- (08 - 44) -
EXTERNAL INPUT
& OUTPUT
EXTERNAL INPUT
& OUTPUT