Rheem RHMV2421MNACJA Service Manual page 187

 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
DIP-SW101-3
Indoor unit fan
setting for
external heater
Heater off
DIP-SW101-3
Indoor unit fan
setting for
external heater
• 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 ≥ 0.9°F
(0.5°C)
*: When 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
4-4. Details of function
Heater is on as shown in following diagram of heating
temperature.
On •
•
•
Enabled
•
•
•
Off •
•
•
Disabled
•
•
Tr-Ts
Off
On
Outdoor temp.
Heat pump only zone
B: 42.8°F (6°C)*
Combination zone
(Heat pump + Heater)
A: -4°F (-20°C)*
Heat pump prohibition zone
Condition
Heater is off as shown in following diagram of heating
temperature.
Other than heating mode
Error occurred
Forced thermostat off
Heat pump only zone
Fan stop protection
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 (=Thon) < -0.9°F (-0.5°C)
Tr: Room temperature
Ts: Set temperature
Thon: Heater on temperature
(Heat pump)
(Heater)
- (05-39) -
4. External input and output