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© 2008 D540e - 02/08
Cool Group Master
Cool Group 1
Master
Member
Member
tN4 Communication
In order to prevent heating and cooling at the same time,
this thermostat can operate together with other thermostats
on a tN4 system to form a cool group.
This thermostat can be set as the cool group master. The
cool group master operates the cooling equipment for
the group. Other thermostats can be set to be members
of the cool group.
When operating as a cool group, the air temperature
readings of all the cool group member thermostats are
communicated to the cool group master and a temperature
average is determined.
This thermostat shows this cool group average temperature
as the “Room” temperature while the mode is set to Cool,
or the mode is set to Auto and the thermostat is allowing
cooling operation. In all other modes, the cool group
master thermostat measures and displays the built-in
“local” temperature sensor measurement.
Fluctuations in the displayed “Room” temperature may
occur during automatic mode switch over when the display
changes from using the local temperature for heating to
using the cool group average temperature for cooling.
When this thermostat is set to Cool mode or is cooling in
Auto mode, the cooling system is operated to maintain
the Set Room Cool setpoint and all thermostats in the
cool group do not operate for air heating. However, cool
group member thermostats that have a floor minimum
temperature set are able to continue heating.
This thermostat is the master of cool group number 1 when
switch setting 3 is set to cool master 1 (Off position).
Backlight
The backlight turns on for 30 seconds once a button is
pressed.
Warm Weather Shut Down
The thermostat indicates warm weather shut down
using the
WWSD
icon. The WWSD feature prevents the
heating system from operating if the outdoor temperature
is above the WWSD temperature. The WWSD feature is
activated by the tN4 System Control. In order to disable
the WWSD, the tN4 System Control’s WWSD setting
must be adjusted.
Freeze Protection
In any event that the room temperature should fall below
40°F (4.5°C), the heating is turned on.
Cycles Per Hour
When the thermostat is on a tN4 bus together with a tN4
System Control, the thermostat operates the heating system
on the cycles per hour determined by the tN4 System
Control. The thermostat automatically determines the
cycles per hour when operating the cooling system.
When the thermostat is not in communication with a tN4
System Control, the Heating Cycles Per Hour setting in the
Adjust menu allows the installer to select Auto or Sync.
When set to Auto, the thermostat automatically determines
the cycles per hour.
When set to Sync, the thermostat synchronizes to cycle
with other thermostats on the tN4 bus.
Synchronization
When the thermostat is on a tN4 bus together with a tN4
System Control, all the thermostats are synchronized to
start heating at the same time. This improves efficiency
of the heating system by reducing short cycles.
When the thermostat is not in communication with a tN4
System Control, the Heating Cycles Per Hour setting in the
Adjust menu allows the installer to select Auto or Sync.
When set to Sync, the thermostat synchronizes with other
thermostats on the tN4 bus.
When set to Auto, the thermostat does not synchronize
with other thermostats.
