The electrical circuit in the unit ventilator is dependent on the controller and sequence that
is being utilized. The unit can be supplied with a 208V, 277V or 460V power supply. The
unit is equipped with an unfused service disconnect. A copy of the electrical schematic can
be found folded in a pouch inside of each unit ventilator, located on the electrical enclosure
or supply air fan housing.
The outdoor air dampers and return air dampers are mechanically linked. As the outdoor
air damper opens, the return air damper closes. A spring return damper actuator is
connected to a linkage set that extends to both sets of dampers. The damper actuator
manufacturer can vary. Please refer to the wiring schematic for the damper actuator model
type.
Internal powered exhaust is an optional feature that is provided with the VHC series. This
feature comes with a spring return damper actuator that is separate from the one used to
control the outside air and return air dampers. However, the powered exhaust damper
actuator is electrically linked to the outside air damper. As the outside air damper opens,
so does the powered exhaust damper.
Typically 1” disposable filters are provided in the unit. Please refer to the “shop drawings”
for specific details on filter construction and thickness. Below are sizes and quantity per
unit for the different model types.
Model Number
Filter Size
Quantity Per Unit
VLC 24, VLC 30, VLC 36
20” x 24” nominal
1
VLC 48, VLC 60
16” x 24” nominal
2
VHC 36, VHC 48, VHC 60
20” x 25” nominal
2
-9-
Electrical Circuit
Dampers
Powered Exhaust (optional)
Filtration
