Rockwell Automation 8720MC High Performance Drives Installation Manual - Manual (Page 71)

Publication 8720MC-IN001D-EN-P — December 2002
Connecting Your 8720MC 3-9
Grounding Your
8720MC We recommend that all equipment and components of a machine or
process system have a common earth ground point connected to their
chassis. A grounded system provides a ground path for short circuit
protection. Grounding your system minimizes the shock hazard to
personnel and damage to equipment caused by short circuits,
transient overvoltages, and accidental connection of energized
conductors to the equipment chassis. For CE grounding requirements,
refer to Chapter 1.
When grounding your 8720MC drive follow these guidelines:
• Identify a good source of earth ground such as a ground rod or a
clean low resistance connection to a steel building structure.
Connect the PE terminal provided on TB1 to earth ground.
• Define the paths through which the high frequency ground
currents flow. Isolate the wires carrying these currents.
• Connect the ground conductor of the motor cable (drive end)
directly to the drive ground PE terminal, not to the enclosure
ground bus bar.
• Ground the CE filter to the bonded cabinet ground bar.
• The D-frame amplifiers (8720MC-D097, -D120, -D149, and -D180)
have a TE terminal. The TE block is used for all control signal
shields internal to the drive. It must be connected to the bonded
cabinet ground bar by a separate continuous lead.
IMPORTANT
To improve the bond between the 8720 system
components and subpanel, construct your subpanel
out of zinc plated (paint-free) steel.