Specifications

Damper Interface — The monitor thermostat is inter-
faced to the damper actuator through the wiring connector
board. The monitor thermostat can be used to control one
master damper and up to 3 slave dampers. See Fig. 30. The
monitor thermostat directly controls only the master damper.
Slave dampers will receive and follow damper position com-
mands sent to the master damper, but do not send informa-
tion to the monitor thermostat.
Damper Modes — The monitor thermostat has 4 modes
of damper operation available:
• system mode
• local mode
• ventilation mode
• IAQ mode
The monitor thermostat selects a damper mode based on
the system mode. If the monitor thermostat has not chosen
a system mode, the monitor thermostat selects a damper mode
based on the local mode.
DAMPER POSITION END SWITCH — The monitor ther-
mostat senses the position of the zone damper actuator through
a solid-state position end switch located on the actuator printed
circuit board. See Fig. 31.
SYSTEM MODE — When central system heating is needed,
the system mode is heating. When central system cooling is
needed, the system mode is cooling.
If the monitor thermostat zone has a heating demand and
the system is in heating mode, the zone damper is modu-
lated in the damper heating mode.
If the monitor thermostat zone has a cooling demand and
the system is in cooling mode, the zone damper is modu-
lated in the damper cooling mode.
If the monitor thermostat zone demand is opposite of the
system mode, or there is no system mode the monitor ther-
mostat will modulate the zone damper in the following modes:
• if there is no system mode, the Ventilation Position option
is set to a value other than 0, and the duct temperature is
between 65 to 80 F, the monitor will modulate the zone
damper in the damper ventilation mode
• if the above conditions are not met, the monitor thermo-
stat will modulate the zone damper to the damper mini-
mum position.
During system mode the damper will modulate according
to zone demand. As the demand is satisfied, the zone damper
closes as demand drops below 1.5° F until it gets to the mini-
mum damper position. If the zone is the reference zone, the
damper remains fully open at the maximum damper
position.
LOCAL MODE — When the monitor thermostat has not
selected a system mode, the monitor thermostat compares
zone temperature to supply-air temperature and determines
the local damper mode.
If the zone damper supply-air temperature is warmer than
the zone temperature and the monitor thermostat is in heat-
ing mode, then the zone damper is modulated in the damper
heating mode.
If the zone damper supply-air temperature is colder than
the zone temperature and the monitor thermostat is in cool-
ing mode, then the zone damper is modulated in the damper
cooling mode.
If the monitor thermostat has no zone heating or cooling
demand, the monitor thermostat will modulate the zone damper
in one of the following modes:
• if the Ventilation Position option is set to a value other
than 0, the monitor will modulate the zone damper in the
damper ventilation mode if the zone temperature is be-
tween 65 and 80 F
• if the Ventilation Position option is set to 0, the monitor
will modulate the zone damper to the damper minimum
position
VENTILATION MODE — The Ventilation Mode option con-
trols which mode the damper will be in if the system has no
zone heating or cooling demand.
If the Ventilation Position option is set to a value other
than 0, the monitor will modulate the zone damper in the
damper ventilation mode. If the Ventilation Position option
is set to 0, the monitor will modulate the zone damper in the
damper minimum airflow mode. During an occupied period,
regardless of zone demand, the monitor thermostat cannot
close the zone damper beyond the Minimum Damper Posi-
tion setting.
To configure the Ventilation Position option, set category 3,
option 3. Use the left set point buttons to toggle the option
from 0 to 7. The default is 5.
NOTE: Only VVTT dampers (2D and RD) can be slaved. High Torque
Actuators (HTA) cannot be slaved.
Fig. 30 — Damper Interface
Fig. 31 — Damper Position Sensor
(End View Shown)
30