69-1493–1
6
T8400C ELECTRONIC THERMOSTAT
Table 1. Heating Cycle Rates.
Optional System Checkout
When in steps 2 and 3 only, the
▼
key can be
used to turn heat or cool outputs on and off.
Change the SYSTEM switch setting to test heat
or cool outputs. No action takes place if the
SYSTEM switch is in the Off position.
Examples: System setting at HEAT: If heat is
on, the
▼
key turns it off; if heat is
off,
▼
turns it on.
System setting at COOL: If cool is
on,
▼
key turns it off; if cool is off,
▼
turns it on.
2. Press the
▲▼
keys simultaneously for more than
one second to light all segments on display and to
enter installer setup mode. When the keys are
released, a two-digit software revision code is
displayed.
NOTE:
In installer setup mode only, each press of
the
▲
key momentarily displays 01. Each
press of the
▼
key momentarily displays
02. When the keys are released, these two-
digit codes are no longer displayed.
3. Press the
▲
key. Factory information is displayed. A
typical example is shown, but information displayed
varies by model. This information is for factory use
only.
4. Press the
▲
key again to display
°
C or
°
F.
System
Cycles Per Hour
Steam, Gravity
1
Hydronic Heat, Condensing Gas
Furnaces
a
3
Gas or Oil Forced Air
6
Electric Heat
9
Special Applications
b
12
5. Press the
▼
key
to change the
°
C or
°
F indication.
6. Press the
▲
key
to display the heat cycle rate of 1,
3, 4, 5, 6, 9, or 12. If the desired cycle is displayed,
press the
▲
key
to exit the installer setup mode. To
change the heat cycle rate, press the
▼
key to scroll
between 1, 3, 4, 5, 6, 9, and 12. Stop scrolling when
the desired rate is displayed. See Table 1 for the
cycle rate options and the corresponding system
equipment.
a
High Efficiency Furnace.
b
Refer to equipment manufacturer’s instructions.
NOTE: Steps 7 and 8 are available on select models.
7. Press the
▲
key to display cooling algorithm
configuration default.
M14684
M14685
M14690
M14686
M14687
M14688
M14689
M18419
8. Press the
▲
key to change cooling algorithm to C1
or C3.
C1 = Standard cooling algorithm.
C3 = Aggressive cooling algorithm (can cause
overshooting).
9. Press the
▲
key to save all changes, exit installer
setup mode and return to normal operation.
NOTE:
After exiting installer setup mode, change the
setpoint to the desired room temperature.
CHECKOUT
Heating
1. Slide the SYSTEM switch to Heat and the FAN
switch to Auto.
2. Press and hold the
▲
key to raise the temperature
setting several degrees above the room tempera-
ture. After approximately ten seconds, the heating
equipment should start. In conventional systems, the
system turns on the fan using a time delay relay or a
limit control. When using an electric heat thermostat,
the fan starts immediately.
3. Press the
▼
key to lower the temperature setting
below the room temperature. Heating equipment
should stop.
4, 5, 12
