IM 178 / Page 23
Damper Assemblies
The optional damper assemblies described in this section
are provided with manually adjustable linkages, or may be
shipped with factory installed actuators and linkages.
Economizer dampers
Outside air intake is provided on both sides of the unit, and
the return air path is at the center of the damper set. As the
single actuator modulates the outside air dampers open, the
return air dampers close. Exhaust air exits the unit through
the gravity relief dampers provided at the end of the econo-
mizer section.
The outside air return air damper assembly (economizer)
comes with manually adjustable linkage. This adjustable
linkage can also be used for connection of a damper operator.
The damper is set so that the crankarm moves through a
90-degree angle to bring the economizer dampers from full
open to full close. Mechanical stops have been placed in the
crankarm mounting bracket. Do not remove stops. If the
crankarm is driven past the stops, damage to the linkage or
damper will result. The unit will ship with a shipping bolt securing
the linkage crankarm. Remove shipping bolt before use.
Figure 17a.
Figure 17b.
Economizer
Optional Return Air Fan
Outside
Air
f
d
Outside
Air
Shaft, .500 Dia.
x 1.50 Long
.25
90
°
Stroke
OA
Closed
OA
Open
.75
Figure 17c.
Note: For good airflow control, adjust linkages so damper
blades do not open beyond 70 degrees. Opening a damper
blade beyond 70 degrees has little effect on its airflow.
Do not “overclose” low leak damper blades. The edge seal
should just lightly contact the adjoining blade. The blades will
lock up if they are closed so far the seal goes over center.
3.00
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
