© 2008 D 540e - 02/08
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Outdoor Temperature Display
When the thermostat is connected to a tN4 system that
includes an outdoor sensor, the outdoor temperature is
displayed in the upper right hand corner of the display.
Schedules
This thermostat, when connected to a tN4 communication
bus, can follow a programmable schedule in order to
automatically lower the room temperature setting.
Lowering the room temperature setting reduces the
amount of fuel required to heat the building resulting in
energy savings.
For this thermostat to follow a schedule, a device called
a schedule master is required. A schedule master can
be a programmable tN4 Thermostat 546e or 542e, a
programmable tN4 Timer 033e, or other tN4 devices that
indicate they are a tN4 schedule master.
The schedule master may support multiple system
schedules. This thermostat can follow either system
schedule 1 or 2.
To follow a schedule:
•
•
Select switch setting 1 to Setback (On position).
•
•
Locate the schedule item in the Adjust menu. Select
either system schedule 1 or 2.
540e
tN4 Communication
Programmable
Schedule
Device
Schedule Master
Optimum Start
When a programmable schedule is selected, there is
a time delay for the temperature to change from the
temperature to the temperature.
The thermostat uses an Optimum Start feature to predict
the heat up rate of the room. The optimum start feature
allows the room to reach the set room temperature by
the time set in the programmable schedule.
During the time period, the user may notice the heat
being on even though the room temperature is above
the set room temperature. This is due to the Optimum
Start feature heating the room in order to reach the
temperature on time.
The Optimum Start applies for both the heating and the
cooling systems. When the mode is set to Auto, Optimum
Start prioritizes for the heating system.
Optimum Start
10P.M.
5A.M. 8A.M.
Occ
70°F (21°C)
UnOcc
65°F (18°C)
Room
Temp.
Recovery Period
Optimum
Start
Setback
Period
Scene
Room Temperature Setting
1
Follows programmable schedule if available.
If there is no schedule, operates at the
occupied temperature.
2
Away temperature.
3
Unoccupied
temperature.
Scenes
Scenes are system wide manual overrides. By changing
the scene number, all scene participating thermostats
change their operating temperature at the same time.
The scene overrides any time-scheduled changes in
temperature.
The purpose of scenes is to provide a quick and convenient
method to lower the heating temperature (raises the
cooling temperature) on multiple thermostats throughout
a building. This reduces the amount of fuel required to
heat the building resulting in energy savings.
Scenes are often used when leaving on vacation, holidays,
or special events.
In order to use the scene feature, a device called a User
Switch (sold separately) can be used to change the
scene number.
This thermostat supports scenes 1, 2, and 3. Scenes 4
through 8 are not supported. Should a permanent scene
4 or 5 be activated, the thermostat operates in scene 1.
Should a temporary scene 6, 7, or 8 be activated, the
thermostat does not change and remains in the last
supported scene.
This thermostat can participate with scenes when switch
setting 2 is set to scene (On position).
User Switch
