Rockwell Automation 1771-A2BSS_A3B1SS Install Instruc Universal I/O Chassis - Manual (Page 4)

Universal I/O Chassis 4
Publication 1771–5.60 – May 1999
If you have this I/O chassis Type of mount
1771-A2BSS panel mount (rear mount)
1771-A3B1SS panel mount (rear mount)
Each enclosure must contain a central ground bus. The ground bus
is the common connection for each chassis within the enclosure and
the enclosure itself. Use either bolts or welded studs to mount the
I/O chassis and central ground bus. If you are mounting a chassis to
the back panel of an enclosure, use 1/4-20 (M6 x 10) mounting bolts.
17666
back-panel
back wall of enclosure
welded stud
Use a wire brush to remove
paint from threads to
provide a ground connection.
star washer
nut
ground bus or
mounting bracket
back-panel
tapped hole
bolt
star washer
flat washer
flat washer
star washer
17665
nut
ground lug
17664
mounting bracket
or ground bus
back wall of enclosure
welded stud
flat washer
flat
washer
star washer
nut
ground lug
Stud Mounting of the Back-panel to the Back Wall of the Enclousure Bolt Mounting of a Ground Bus or Chassis to the Back-panel
Stud Mounting of a Ground Bus or Chassis to the Back-panel
scrape paint on panel
scrape paint on panel
scrape paint from mounting
bracket or ground bus
scrape paint from threads
!
ATTENTION: If the mounting brackets of a chassis
do not lay flat before the nuts are tightened, use
additional washers as shims so that the chassis will not
be warped by tightening the nuts. Warping a chassis
could damage the backplane and cause poor
connections.
Mount the I/O Chassis
and Ground Bus