Rockwell Automation 1715-OF8I Redundant I/O System User Manual - Manual (Page 78)

78 Rockwell Automation Publication 1715-UM001C-EN-P - March 2014
Chapter 2 Installation Instructions
Wire the Ground Connection
The system can have up to three separate ground systems:
• An AC Safety Ground (sometimes called the ‘dirty ground’) to protect
you in the event of a fault. The ground stud on the adapter base unit must
be connected to the AC safety ground, along with all exposed metalwork,
such as DIN rails.
• An Instrument Ground (sometimes called the ‘clean ground’ or ‘OV DC
ground’) to provide a good stable OV reverence for the system. Every
signal return must be referenced to the instrument ground, which is
isolated from the AC Safety Ground.
• Some field wiring needs shielded (screened) cable. There can be a Shield
Ground in addition to the AC Safety and Instrument Grounds to provide
a common point to terminate cable shields.
Connect the adapter base unit ground stud to the AC safety ground bus bar of
the system:
• Use an M6 lug on the end of the ground wire.
• Place the lug below the second nut on the ground stud between two
washers and use two 10 mm (.039 in.) wrenches to tighten the nuts.
• Use a minimum conductor wire size of 4 mm
2
(10 AWG).
Figure 29 - Adapter Base Unit Ground Connection Detail
MP-PWR-24V1
OV MP-PWR-24V2
OV
32125-M
AC Ground Connection Only