Spec Sheet

Table Of Contents
THX9321 PRESTIGE
®
2.0 AND THX9421 PRESTIGE
®
IAQ WITH EIM
68-0311—07 128
Economizer and Time of Day (TOD)
Operation
Economizer
The thermostat controls an economizer module to provide
ventilation during occupied periods and free cooling when
outdoor conditions are favorable. In some climates the
cooling system may run several hours when it may not be
required to maintain indoor comfort. When outdoor
conditions are favorable, ventilation with outdoor air can
achieve the same level of comfort at lower cost. Table 9
explains how the Economizer Module is controlled by the
thermostat.
The thermostat works with the Jade W7212 Economizer
Module for conventional systems and the Jade W7213
and W7214 Economizer Modules for heat pump systems.
Time of Day (TOD)
The thermostat can be set up for a Time of Day output in
the installer setup. This output is commonly used to
control lighting panels, turning them on for occupied
periods and off for unoccupied periods. Table 10 explains
how the TOD feature works with various thermostat
modes.
The Economizer Module and Time of Day output connect
to the A-L/A terminal at the thermostat or EIM and are set
up at ISU 2220.
Fig. 310.
Pre-Occupancy Purge
The thermostat can be set up for Pre-Occupancy Purge in
the installer setup (ISU 4010). When setup for Pre-
Occupancy Purge, the thermostat runs the fan 1 to 3
hours before each occupied period to provide a
comfortable workplace upon arrival. Options are Off and 1
to 3 hours.
Fig. 311.
Table 9. Economizer Operation.
Thermostat
Mode Equipment Operation
A-L/A
terminal:
Economizer
Occupied Heat/Cool/Fan running
ON
Occupied
temporarily
Heat/Cool/Fan running
Occupied Heat/Cool/Fan NOT
running
Occupied
temporarily
Heat/Cool/Fan NOT
running
Pre-occupancy
purge
Fan running
Unoccupied Cooling system running
Unoccupied
temporarily
Cooling system running
Standby Cooling system running
Unoccupied Cooling system NOT
running
OFF
Unoccupied
temporarily
Cooling system NOT
running
Standby Cooling system NOT
running
ON
Non-
programmable
Fan running
Non-
programmable
Fan NOT running OFF
Table 10. TOD Operation.
Thermostat Mode
A-L/A
terminal: TOD
Occupied
ONOccupied temporarily
Temperature overrides
Unoccupied
OFF
Unoccupied temporarily
Standby
Non-programmable