Viking VBCV4238 Installation Instructions Manual Download Page 6

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WALL INSTALLATION
EXTERIOR-POWER VENTILATOR

VEV900-Exterior-Power Ventilator Kit (900CFM)

1. Choose a position on the outside wall. Min. 24” (61.0

cm from ground may vary depending on local codes
or location. Make sure that no wall studs, pipes or
wires run through the opening area.

2. Drill a guide hole at the center of the opening area.
3. From the outside, use the guide hole as a starting

point to lay out the installation.

A. Use a T-square to measure 10

3/4

” (27.3 cm) to the

left of the guide hole, then 12

7/8

” (32.7 cm) to

locate the top-left corner of the layout.

B. Starting from the top -left corner, mark a 25”

(63.5 cm) by 28

1/2

” (72.4 cm) rectangle on wall

located from guide hole.

4. Cut a rectangular hole in the siding only. Do not cut

the sheathing. Nail down all siding ends.

5. Mark an 11” (27.9 cm) diameter circle centered on the

guide hole and mark the center of the 1

1/4

” diameter

electrical wiring hole.

6. Cut the 11” (27.9 cm) hole in the sheathing and drill

the 1

1/4

”(3.2 cm) as marked.

7. Place a large bead of caulk on the back side of the

housing along the outer edge.

8. Center the blower ring in the 11” (27.9 cm) diameter

hole, making sure that the 1

1/4

” (3.2 cm) diameter

electrical wiring hole aligns with the hole in the wiring
box.

9. Attach blower to the wall with the six screws

provided. It is recommended that the screws
be located inside the blower housing. All six
holes in the back panel must be filled, or any
moisture that may get inside the housing could
leak into the house.

10. Using a good grade of caulk, seal all around the

mounting screw heads.

11. Bring electrical wiring through the hole in the

wiring box and secure it according to local
codes.

12. Make the electrical connections with the proper

connector for the type of wire being used.
Connect white to white, black to black, and
green or bare wire to green.

13. Replace wiring box cover and screws. Do not

pinch wiring under cover.

14. Check for free movement of the damper before

installing housing cover and screws.

15. Turn on power and check operation of the blower.
16. Top and side flanges of the back plate may be

covered with trim strips. Do not block grill opening at
bottom with trim. It will adversely affect performance
of the blower.

Black
to
Black

120 VAC
Line In

White
to
White

Green to
Green

11” (27.9 cm)
dia. hole

Guide
Hole

8”

(23.2 cm)

4” (18.4 cm)

4” (3.2 cm)

Dia. Hole

12 7/8”

(32.7 cm)

28 1/4”
(71.8 cm)

25” (63.5 cm)

103

4”

(27.3 cm)

WALL CUTOUT

ROOF INSTALLATION
EXTERIOR-POWER VENTILATOR

VEV900-Exterior Power Ventilator Kit (900CFM)

(also see instructions supplied with ventilator kit)

1. Locate the blower on the rear slope of the roof. Place it

in a location to minimize duct run.  The location should
be  free  of  obstacles  (T.V.  leads,  electrical  lines,  etc.).
Bear  in  mind,  if  the  blower  top  is  level  with  the  roof
peak,  it  will  not  be  seen  from  the  street.    Keep  this
approximate  location  in  mind  as  you  work  from  within
the attic.

2.  Mark a point halfway between rafters.
3.  Drill a guide hole through the roof at this point.
4.  From the outside, use the guide hole as a starting point.

A. Use a T-square to measure 8

1/2

” (21.6 cm) to the left

of the guide hole, then down 10

3/8”

(26.4 cm) to

locate the bottom left corner of the layout.

B. Mark the rectangular cutout and remove only the

shingles in this area.

5. Mark an 11” (27.9 cm) diameter circle centered on the

guide hole and mark the center of the 1

1/4

” (3.2 cm)

diameter electrical wiring hole.

6. Cut out the roof board(s) along the 11” (27.9 cm)

diameter circle and drill a 1

1/4

” hole as marked.

7. For flat roof installations, build a curb that will mount the

blower at a minimum pitch of 2/12. Discharge end of the
blower should be pointed away from prevailing winds.

8. Remove roofing nails from the upper two-thirds of the

shingles around the cutout area. Carefully lift the
shingles to allow the back flashing sheet on the blower
housing to fit under them.

9. Center the blower ring in the 11” (27.9 cm) diameter

hole, making sure that the 1

1/4

” (3.2 cm) diameter

electrical wiring hold aligns with the hole in the wiring
box.

10. Attach the blower to the roof with the six screws

provided. It is recommende that the screws be located
inside the blower housing. All six holes in the back
panel must be filled, or any moisture that may get inside
the housing could leak into the house.

11. Using a good grade of roofing cement, seal all of the

shingles around the housing and flashing sheet as well
as the mounting screw heads.

12. Bring electrical wiring through the hole in the wiring

box and secure it according to local codes.

13. Make the electrical connections with the proper

connector for the type of wiring being used. Connect
white to white, black to black, and the green or bare
wire to green.

14. Replace wiring box cover and screws. Do not pinch

wiring under the cover.

15. Check for free movement of the damper before

installing housing cover and screws.

16. Turn on power and check operation of the blower.

Guide
Hole