Nextra 3291027 Guide D'installation page 10

Warning:
Turn power off at the electrical panel before beginning
installation.
 Installation I (joist mounting)
1. Insert the support brackets in the slots on the fan housing. If spacing
between joists is 21 ¼" to 23 ½" (54 cm to 59.7 cm) connect support
brackets I and II (Fig. 1).
2. Mount the fan housing to joist using the support brackets
and long screws (Fig. 2-1 or Fig. 2-2 and 2-3).
CAUTION:
Dimension "B" should include the ceiling thickness. Do not flush mount
to joist. Flange should be flush with ceiling board (Fig. 2-1a).
Housing
Bracket
Long screws
Figure 2-1
Housing
Figure 2-2
4
Joist
Joist
2 screws
Support bracket I
Figure 1
Joist
Bracket
B
Ceiling
Figure 2-1a
2 long screws
Figure 2-3
Insert
support
brackets
Support bracket II
Housing