If you are installing external
blower on a flat roof:
2 x 4 framing
Locate the 11" (27.9 cm) dia. hole
Build a sloping base that will mount the
exterior blower at a minimum pitch of
2-1/2" (6.4 cm). Weatherproof the base
Locate the base so that the exterior
blower's vent aligns with the 11"
(27.9 cm) dia. hole and the blower sits
evenly on the base with no gaps. Note:
Make sure that the discharge end of the
exterior blower faces away from the
direction of prevailing winds.
Use dimensions from either FIGURE 1
or 2 (Page 3) to locate the 1-1/4"
(3.0 cm) dia. wiring hole.
Remove roofing nails from the
upper two-thirds of the shingles to allow
the back flashing sheet on the exterior
blower housing to fit under them.
Center the exterior blower ring in
the 11" (27.9 cm) diameter hole, making
sure that the 1-1/4" (or 3.0 cm) diameter
electrical wiring hole lines up with the
hole in the wiring box.
Attach the exterior blower to roof
or frame using screws appropriate for
your installation. All four holes in the
back panel must be filled to prevent
moisture that may get inside the remote
blower housing from leaking into the
Seal all the shingles around the
exterior blower housing, flashing sheet,
and mounting screw heads or frame with
Top and side flanges of the back plate
may be covered with trim. It is
recommended that electrical connection
be made and checked first. Do not block
the vent grill opening at the bottom of
the trim. Doing so will decrease blower
11" (27.9 cm)
Electrical Shock Hazard
Disconnect power before
making electrical connections.
Connect the ground wire to
green ground screw in wiring
Failure to do so can result in
death or electrical shock.
Remove the cover from the exterior
blower. Then remove the wiring box cover.
Pull electrical wiring through the
hole in the blower base and secure it
according to local codes.
Attach the black plastic vent collar
to the exterior blower with the four screws
provided. Connect the vent system to this
collar and seal the connection securely
with duct tape.
Make the electrical connections.
(See FIGURE 3 and wiring diagram.)
Connect the white and black wires of the
power supply cable wire to the white and
black wires in the wiring box with twist-on
Connect the green power supply ground
wire to the green ground screw.
Replace the wiring box cover and
screws taking care not to pinch the wiring
under the wiring box cover.
Turn on power (See Use and Care
Guide that came with your vent hood
system). Check operation of blower and
make sure damper is opening freely.
Reinstall exterior blower housing.