Allen-Bradley MicroLogix 1200 Notice D'installation page 16

16 MicroLogix™ 1200 Programmable Controllers
Grounding the Controller
In solid-state control systems, grounding and wire routing helps limit the effects
of noise due to electromagnetic interference (EMI). Run the ground connection
from the ground screw of the controller to the ground bus prior to connecting any
devices. Use AWG #14 wire. This connection must be made for safety purposes.
ATTENTION: All devices connected to the RS-232 channel must
be referenced to controller ground or floating. Failure to follow this
!
procedure may result in property damage or personal injury.
For 1762-L24BWA and 1762-L40BWA controllers:
• Chassis ground, user 24V ground, and RS-232 ground are
internally connected. You must connect the chassis ground
terminal screw to chassis ground prior to connecting any
devices.
• The user supply 24V dc IN ground and chassis ground are
internally connected.
• The 24V dc sensor power source should not be used to power
output circuits. It should only be used to power input devices.
You must also provide an acceptable grounding path for each device in your
application. For more information on proper grounding guidelines, refer to the
Industrial Automation Wiring and Grounding Guidelines, publication 1770-4.1.
1762-IN006A-ML-P