Rockwell Automation 1336T Wiring and Grounding Guide, (PWM) AC Drives - Manual (Page 60)

60 Rockwell Automation Publication DRIVES-IN001M-EN-P - March 2014
Chapter 4 Best Practices
Conduit Entry Entry Plates
In most cases, the conduit entry plate is a conductive material that is not painted.
Make sure that the surface of the plate is clean of oil or contaminants. If the plate
is painted, follow one of these steps to make a good connection:
• Use a connector that cuts through the paint and makes a high quality
connection to the plate material.
• Remove the paint around the holes down to the bare metal one inch in
from the edge of the plate. Grind down the paint on the top and bottom
surfaces. Use a high quality joint compound when reassembling to help
prevent corrosion.
Cable Connectors/Glands
Choose cable connectors or glands that offer the best cable protection, shield
termination, and ground contact. Refer to
Shield Termination on page 69 for
more information.
Shield Terminating Connectors
The cable connector must provide good 360
o
contact and low transfer
impedance from the shield or armor of the cable to the conduit entry plate at
both the motor and the drive (or drive cabinet) for electrical bonding.
SKINTOP
MS-SC/MS-SCL cable grounding connectors and NPT/PG
adapters from LAPPUSA are good examples of this type of shield terminating
glands.
Figure 23 - Terminating the Shield with a Connector
U (T1)
V (T2)
W (T3)
PE
Braid wires pulled back in a 360
° pattern
around the ground cone of the connector.
Drain wires pulled back in a 360
° pattern
around the ground cone of the connector.
Metal locknut bonds the
connector to the panel.
Metal connector body makes direct
contact with the braid wires.
Ground Bushing
One or More
Ground Leads
IMPORTANT This is mandatory for CE compliant installations, to meet requirements for
containing radiated electromagnetic emissions.