INSTALLATION MANUAL FXMQ_PB/FBQ ECONOMIZER
5
C.
Fan Mode
1.
While in fan only operation, cooling thermo-off, and heating thermo-off, the damper will open to the minimum vent
position. The minimum vent position is site-configurable.
D.
Enthalpy Control
1.
The enthalpy economizer control senses both temperature and humidity of the outside air. When the heat content
of the outside air is below the control set point, the control permits the outside air dampers to operate as described
in section 5.A.2. above. When the heat content rises above the control set point, the control closes the outdoor air
dampers to the minimum vent position. This setpoint can be adjusted as needed.
Figure 2. Single Enthalpy Curve and Boundaries
Table 3. Single Enthalpy and Dual Enthalpy High Limit Curves
E.
Settings
1.
The mixed air temperature set point must be no lower than 65
°
FDB for continuous operation. This may be
configured down to 60
°
FDB, however thermo off may be carried out due to freeze protection.
2.
The economizer is recommended for standard comfort cooling applications only. This must not be used for high heat
density, year round cooling applications.
3.
The enthalpy curve setting must not be programmed to ES4 or ES5.
6.
Wiring Diagram
Provide field supplied 24VAC power supply and 18 gauge, stranded wire as indicated in Figure 3. All wiring and electrical work
should conform to applicable national, state, and local codes.
