Rockwell Automation 1336T Wiring and Grounding Guide, (PWM) AC Drives - Manual (Page 70)

70 Rockwell Automation Publication DRIVES-IN001M-EN-P - March 2014
Chapter 4 Best Practices
Shield Termination via Pigtail (lead)
If a shield terminating connector is not available, the ground conductors and/or
shields must be terminated to the appropriate ground terminal. If necessary, use a
compression fitting on the ground conductors, or shield together as they leave the
cable fitting.
Pigtail termination is not recommended for these conditions:
• If the cable length is greater than 1 m (3.2 ft) or extends beyond the panel
• If used in very noisy areas
• If the cables are for noise sensitive signals (for example, registration or
encoder cables)
• If strain relief is required
If a pigtail is used, pull and twist the exposed shield after separation from the
conductors. To extend the length, solder a flying lead to the braid.
Shield Termination via Cable Clamp
Standard Cable
Grounding cable glands are a simple and effective method for terminating shields
while offering excellent strain relief. They are applicable only when entry is
through a cabinet surface or bulkhead.
The cable connector must provide good 360° 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.
IMPORTANT Pigtail termination is the least effective method of noise containment.
SKINTOP MS-SC/MS-SCL cable grounding
connectors and NPT/PG adapters from LAPPUSA
are good examples of standard cable clamp shield
terminating gland.