Carrier P474-1100RF Owner's Manual page 17

MEMORY BACKUP - In the event of a power loss, the
thermostat will retain the stored program settings without
external power or batteries.
2 STAGE OPERATION - The 2nd Stage of heat or cool is
turned on when (1) the 1st Stage has been on for a
minimum of two minutes, and (2) the temperature spread
from the setpoint is equal to or greater than: the setpoint
plus the deadband, plus 2 degrees.
Heating Cooling
75 FX
2nd Stage 1st Stage Heat Cool 1st Stage 2nd Stage
turn on tam on Setpoint Setpoint turn on turn on
MINIMUM HEAT/COOL SETPOINT DIFFERENCE - The Heat
and Cool setpoints will not be allowed to come any closer
to each other than the value set in Advanced Setup step
# 7, on page 13. This minimum difference is enforced
during Auto changeover and Program On operation.
PROGRAMMABLE FAN - If the Programmable Fan timer is
set to a value other than 0, the fan will run for the
preprogrammed amount of time, page 14, step# 10.
The Programmable Fan timer will start the fan at the top
of each hour. The Programmable Fan may be active
even if the thermostat mode is Off.
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