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506071−01 02/08
If the Fahrenheit/Celsius display must be changed, use a
plastic, non−conductive tool to push the dip switch to the
right position (see figure 18).
F/C (Fahrenheit/Celsius) switch
shown in Celsius position
1
2
3
4
5
6
7
PLUG IN (Use Care To Avoid Bending Prongs.)
Figure 18. Changing Fahrenheit/Celsius Setting
Indoor Temperature Measurement Range
Measurement Scale
Fahrenheit
. . . . . . . . . . . . . . . . . . . .
Measurement Range
35°F to 99°F
. . . . . . . . . . . . . . . . . .
Measurement Resolution
0.5°F
. . . . . . . . . . . . . . . . . . . . .
Measurement Accuracy
+/−1°F
. . . . . . . . . . . . . . . . . . . . . .
Field Offset
via DIP switches to +/−3°F
. . . . . . . . . . . . . .
Sampling Method: temperature measurements sampled
every 15 seconds. Displayed temperature is the average
of the last four measurements.
Outdoor Temperature Measurement Range
Measurement Scale
Fahrenheit
. . . . . . . . . . . . . . . . . . . .
Measurement Range
−22°F to 122°F
. . . . . . . . . . . . . . . .
Measurement Resolution
1°F
. . . . . . . . . . . . . . . . . . . . . . .
Measurement Accuracy
+/−2°F
. . . . . . . . . . . . . . . . . . . . . .
Temperature Setpoint Range
Setting range
50°F (10°C) to 90°F (32°C)
. . . . . . . . . . . .
Setting resolution
1°F (1°C)
. . . . . . . . . . . . . . . . . . . . . . . . .
Smart Setback Recovery (via DIP switch #6)
Smart Setback Recovery (SSR) affects the way the ther-
mostat responds to program events. If SSR is disabled, the
thermostat will react to a program event at the time the
event occurs. However, if SSR is enabled, the thermostat
will react to a program event before the event occurs such
that the desired temperature is reached at the time of the
event, not after.
Autochangeover Deadband Selection (via DIP
switch #7)
Autochangeover deadband can be set to 4
or 6 degrees. When autochangeover is enabled (via the
AUTO button), the thermostat will automatically change
over from heating to cooling and vice versa, to keep the
room temperature in between the heating and cooling set-
points. The deadband is the minimum difference between
the heating and cooling setpoints.
Fan Control
AUTO or ON modes, gas or electric heat
compatible via DIP switches (also see Thermostat Output
section).
I/O Relays
All thermostat relays are latching type to
minimize power consumption.
Equipment Protection Timers
Minimum Compressor OFF time
5 minutes
. . . . . . . . . . .
Minimum Compressor ON time
4 minutes
. . . . . . . . . . . .
Minimum Furnace ON time
3 minutes
. . . . . . . . . . . . . . .
Minimum furnace cycle time (elapsed time between any
furnace activation & next furnace activation)
6 minutes
Minimum elapsed time between any compressor activa-
tion and the next compressor activation
6 minutes
. . . .
NOTE − All protection timers (except the compressor OFF
timer) can be over−ridden if a heating or cooling demand is
initiated or terminated using the UP, DOWN, HEAT, or
COOL buttons.
Equipment Protection Override
Both the minimum
compressor OFF timer and the minimum equipment cycle
timer can be over−ridden by pressing and holding either the
HEAT or COOL button down for 4 seconds.
Over Temperature Protection
Thermal-mechanical
switch opens W1 and W2 at 93°F+/−6°F.
Filter Reminder
Settings of Off, 1, 3, 6 or 12 (months
of fan run time) are available. When programmed time has
elapsed, a FILTER indicator is displayed.
Maintenance Reminder
Settings of Off, 6 or 12
(months of chronological time) are available. When pro-
grammed time has elapsed, a maintenance indicator
MAINTENANCE" is displayed.
Service Reminder
The SERVICE indicator is dis-
played only under the following conditions:
S
if the thermostat Y1 terminal has been activated with
24VAC for at least 5 minutes, AND the L terminal is
shorted to the R terminal;
OR
S
if the thermostat Y1 terminal has been activated with
24VAC for at least 5 minutes, AND the L terminal is
shorted to the C terminal.
Power Loss/Recovery
Thermostat memory is re-
tained for a minimum of 24 hours during a power loss (in-
cludes retention of clock setting, program information,
HOLD status, programmed temperature setpoint, heat/
cool and fan mode settings, filter reminder status, mainte-
nance reminder status, and equipment protection timers).
After 24 hours of power loss, programmed settings will be
lost and replaced with default settings.
IMPORTANT
Power must be applied for at least six consecutive
hours prior to a power loss in order for memory to
be retained for the specified time.
LCD Backlight
Activated for 30 seconds when any
button is pressed.
NOTE − During an electrical storm or similar disturbance,
the backlight may activate for a few seconds. This is nor-
mal and will no longer occur after the electrical disturbance
has passed.
Thermostat Operating Conditions
35°F to 105°F
.
5% to 90% RH
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermostat Storage Conditions
−40°F to 185°F
. .
5% to 95% RH
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
