Rockwell Automation 1770 Industrial Automation Wiring and Grounding Guidelines - Manual (Page 7)

Industrial Automation Wiring and Grounding Guidelines 7
Publication 1770-4.1 – February 1998
Figure 4
Details of Ground Connection at Enclosure Wall
and use a star washer.
10020
Enclosure
Wall
Scrape
Paint
Bolt
Scrape paint on enclosure wall
Ground
Lug
Nut
Star
Washer Equipment-
Grounding
Conductor
Connect an equipment grounding conductor directly from each
chassis to an individual bolt on the ground bus. For a chassis with
no ground stud, use a mounting bolt (Figure 5). For those chassis
with a ground stud, use the ground stud for this connection
(Figure 6).
Figure 5
Details of Ground Connection at Mounting Bracket of
Chassis with No Ground Stud
If the mounting bracket is coated with a
non-conductive material (anodized,
painted, etc.), scrape the material
around the mounting hole.
Mounting Bracket
Nut
Back Panel
Welded Stud
Scrape paint
17666
Flat
Washer
Flat
Washer
Star
Washer
Ground
Lug
For a power supply without a groundable power supply chassis (such
as a power-supply module or mini-processor with an integral power
supply), or a power supply (such as the 1771–P7 or 1771–PS7) with
a chassis that is not internally connected to its GND terminal, use a
14 AWG copper wire to connect its GND terminal to the ground stud
or mounting bolt connected to the ground bus. This will ensure an
adequate ground for noise immunity.