Rockwell Automation 1326 Digital AC Multi-Axis Motion Control System User Manual - Manual (Page 50)

Publication 1394-5.0 — May 2000
3-4 Wiring System, Axis, and Shunt Modules, and Motors (for all systems)
System Module Wire Sizes
All wire sizes in this manual are recommended minimums. Assume
that wires are type MTW copper wire (machine tool wire, 75° C,
minimum) per NFPA 79 unless otherwise noted. Consult the National
(or local) Electrical Code for factors related to ambient conditions,
length, etc. See your Allen-Bradley Sales Representative for more
information.
Shielding
To minimize radiated and induced noise problems or ground loops,
separate feedback, command, and other shields from each other and
connect them at a common machine or system earth ground. Connect
all shields to a single earth ground point. Refer to Grounding Your
1394 System in this chapter and Appendix B for additional
information.
Insulate the open-ended shields (resolver feedback cable at the
resolver and velocity command cable at the servo drive) so that they
do not cause ground loops.
EMI/RFI Shielding
The 1394 has an inverter carrier frequency of 5000 Hz. The drive’s
output inverter switching sequence produces a carrier frequency of
10,000 Hz when measured at the motor. This can induce noise into
sensitive equipment lines adjacent to it.
EMI/RFI Bonding
The metal chassis of electrical components should be bonded to the
subpanel in an electrical cabinet with metal to metal contact. The
purpose of a high frequency (HF) bond is to provide HF noise
currents a path of least impedance to return to their source.
!
ATTENTION: This system can produce
electromagnetic radiation that can cause industrial or
radio-controlled equipment to operate erratically and
cause possible injury to personnel. The 1394 system is
designed to be interconnected with Allen-Bradley EMI
shielded motor cables only. Do not substitute cables.
The EMI shield of the motor power cable must be
grounded at both ends to function properly.