Lennox KGC Series Unit Information page 46

ECONOMIZER OPERATION-OUTDOOR AIR IS SUITABLE FOR FREE COOLING -- FREE COOL LED "ON"
Thermostat Demand
Off
G
Y1
Y2
Y3
ECONOMIZER OPERATION-OUTDOOR AIR IS NOT SUITABLE FOR FREE COOLING -- FREE COOL LED "OFF"
Thermostat Demand
Off
G
Y1
Y2
*IAQ sensor can open damper to DCV max.
H-Outdoor Air Dampers
Optional manual and motorized outdoor air dampers
provide fresh outdoor air. The motorized damper assembly
opens to minimum position during the occupied time
period and remains closed during the unoccupied period.
Manual damper assembly is set at installation and
remains in that position. Set damper minimum position
in the same manner a seconomizer minimum position.
Adjust motorized damper position using the thumbwheel
on the damper motor. See FIGURE 35. Manual damper
fresh air intake percentage can be determined in the same
manner.
I-Gravity Exhaust Dampers
Dampers are used in downflow (FIGURE 36) and
horizontal (FIGURE 37) air discharge applications.
Horizontal gravity exhaust dampers are installed in the
return air duct. The dampers must be used any time an
economizer and a power exhaust fan is applied to KGC
series units Gravity exhaust dampers allow exhaust air to
be discharged from the system when an economizer and/
or power exhaust is operating. Gravity exhaust dampers
also prevent outdoor air infiltration during unit off cycle.
See installation instructions for more detail.
DAMPER MOTOR
THUMBWHEEL
FIGURE 35
TABLE 23
Damper Position
Unoccupied
Closed
Closed
Modulating
Modulating
Modulating
TABLE 24
Damper Position
Unoccupied
Closed
Closed
Closed
Closed
NOTE - GED is optional except when used with power
exhaust dampers, where it is required.
Page 46
Occupied
Closed
Minimum
Modulating
Modulating
Modulating
Occupied
Closed
Minimum*
Minimum*
Minimum*
GRAVITY EXHAUST DAMPERS - DOWNFLOW
HOOD TOP
HOOD TOP
SUPPORT
FIGURE 36
GRAVITY EXHAUST DAMPERS - HORIZONTAL
RETURN AIR PLENUM
13
(330)
29-1/2
(749)
FIGURE 37
Mechanical Cooling
No
No
No
Stage 1
Stage 2
Mechanical Cooling
No
No
Stage 1
Stage 2
DAMPER
ASSEMBLY
6-1/2
(165)