Rockwell Automation Allen-Bradley MicroLogix 1000 Instructions D'installation page 11

Grounding Your Controller
In solid-state control systems, grounding helps limit the effects of noise due to
electromagnetic interference (EMI). Run the ground connection from the ground
screw of the controller (third screw from left on output terminal rung) to the
ground bus. Use the heaviest wire gauge listed for wiring your controller.
ATTENTION: All devices connected to the user 24V power supply or
to the RS-232 channel must be referenced to chassis ground or floating.
!
Failure to follow this procedure may result in property damage or
personal injury.
Chassis ground, user 24V ground, and the RS-232 ground are internally
connected. You must connect the chassis ground terminal screw to
chassis ground prior to connecting any devices.
On the 1761-L10BWB, -L16BWB, -L16BBB, -L20BWB-5A,
-L32BBB, and -L32BWB controllers, the user supply 24V dc IN ground
and chassis ground are internally connected.
You must also provide an acceptable grounding path for each device in your
application. For more information on proper grounding guidelines, see the
Industrial Automation Wiring and Grounding Guidelines, (publication 1770-4.1).
Installation Instructions
MicroLogix 1000 Programmable
Controllers
Protective
Wrap (remove after wiring)
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