Carrier P374-1500 Owner's Manual page 22

About Advanced Features & Operation
OUTDOOR SENSOR (Optional Accessory) - When connected
to terminals RS+5, RS1, & RS GND on the back of the
thermostat, the thermostat will read the temperature from
the Outdoor Sensor when asked to. This thermostat will
not control to this sensor, it is only to read outside
temperature.
To read the temperature
press the Outside button.
The display will then only show Outside temperature.
Pressing the Outside button will then return the display
to
normal operation.
The Outdoor sensor is also used by the thermostat to
compare the outside temperature to the Changeover
Balance Point.
The Outdoor Sensor is available in a wired or wireless
version. The wired sensor can be connected to the
thermostat with up to 500' of 20 ga. or 300' of 18 ga.
Unshielded, thermostat wire.
See the Outdoor Sensor instructions for further details.
ELECTRIC HEAT - Selecting Electric Heat ON, page 12,
step 5, will cause the thermostat to turn on the fan
immediately any time there is a heat demand during
3rd stage operation only. Electric Heat is only
available if the thermostat is configured for Dual Fuel.
Since all gas furnaces control the fan, this feature
should be OFF unless the 3rd stage is only electric.
from the Outdoor Sensor,
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