Rockwell Automation 1770 Industrial Automation Wiring and Grounding Guidelines - Manual (Page 8)

Industrial Automation Wiring and Grounding Guidelines 8
Publication 1770-4.1 – February 1998
Figure 6
Typical Grounding Configuration
Enclosure Wall
I/O Chassis Wall
Nut
Ground Lug
14 AWG
14 AWG
15317
See Figure 3
See Figure 4
FLEX I/O

Modules
DIN Rail
Star
Washer
Star
Washers
Ground
Lug
Ground
Bus
Mini-processor with
built-in power supply
Power-supply
module
Grounding-
electrode
Conductor
To Grounding-
electrode
System
Equipment-grounding
Conductors 8AWG
Ground
Bus
Equipment-grounding
Conductors 14AWG
1771 Chassis
with 2 Power
Supplies
1771 Chassis
with 1771-P7
Power Supply
1756 Chassis
with 1756-PA72
Power Supply
1771-P7
Power Supply
Do not lay one ground lug directly on top of the other. This type of
connection can become loose due to compression of the metal lugs.
Sandwich the first lug between a star washer and a nut with a captive
star washer. After tightening the nut, sandwich the second lug
between the first nut and a second nut with a captive star washer.