Rockwell Automation 1336Z SPIDER - FRN 2.xxx-5.xxx - Manual (Page 21)

General Installation for All Drives 2–11
Conduit
If metal conduit is preferred for cable distribution, the following
guidelines should be followed.
• Drives are normally mounted in cabinets and ground connections
are made at a common ground point in the cabinet. Normal
installation of conduit provides grounded connections to both the
motor frame ground (junction box) and drive cabinet ground.
These ground connections help minimize interference. This is a
noise reduction recommendation only, and does not affect the
requirements for safety grounding (refer to pages 2–6 and 2–7).
• No more than three sets of motor leads can be routed through a
single conduit. This will minimize “cross talk” that could reduce
the effectiveness of the noise reduction methods described. If
more than three drive/motor connections per conduit are required,
shielded cable as described above must be used. If practical, each
conduit should contain only one set of motor leads.
Motor Lead Lengths
Installations with long cables to the motor may require the addition of
output reactors or cable terminators to limit voltage reflections at the
motor. Excessive cable charging current can also reduce the amount
of current available to produce rated motor torque. Refer to Table 2.E
for the maximum cable length allowed for various installation
techniques. Shaded distances are restricted by cable capacitance
charging current. The figure on the next page illustrates how total
cable length is calculated. Failure to follow these guidelines can result
in poor motor performance and nuisance drive overcurrent or
overload tripping. For installations that exceed the recommended
maximum lengths listed, contact the factory.
Please note that the cable lengths shown are guidelines. Your
application may be restricted to a shorter cable length due to wire
type, wire placement, line reactor and type of motor.
Dynamic Brake Resistor Wiring
All brake resistor wiring must be twisted wire run in conduit separate
from control wiring. Maximum cable length is 2.5 meters (8.2 feet).
Size wire according to the “Brake Current” provided on page A–3.
Brake resistor dimensions and specifications can be found in
Appendix B.
!
ATTENTION: To avoid a possible shock hazard caused by
induced voltages, unused wires in the conduit must be
grounded at both ends. For the same reason, if a drive shar-
ing a conduit is being serviced or installed, all drives using
this conduit should be disabled. This will eliminate the pos-
sible shock hazard from “cross coupled” drive motor leads.