Rockwell Automation 1336F PLUS II User Manual - Firmware 1.xxx-6.xxx - Manual (Page 21)

Installation/Wiring 2–11
Grounding Refer to the grounding diagram on page 2–13 . The drive must be con-
nected to system ground at the power ground (PE) terminal provided
on the power terminal block (TB1). Ground impedance must conform
to the requirements of national and local industrial safety regulations
(NEC, VDE 0160, BSI, etc.) and should be inspected and tested at
appropriate and regular intervals.
In any cabinet, a single, low-impedance ground point or ground bus
bar should be used. All circuits should be grounded independently
and directly. The AC supply ground conductor should also be con-
nected directly to this ground point or bus bar.
Sensitive Circuits
It is essential to define the paths through which the high frequency
ground currents flow. This will assure that sensitive circuits do not
share a path with such current. Control and signal conductors should
not be run near or parallel to power conductors.
Motor Cable
The ground conductor of the motor cable (drive end) must be con-
nected directly to the drive ground (PE) terminal, not to the enclosure
bus bar. Grounding directly to the drive (and filter, if installed) can
provide a direct route for high frequency current returning from the
motor frame and ground conductor. At the motor end, the ground con-
ductor should also be connected to the motor case ground.
If shielded or armored cables are used, the shield/armor should also
be grounded at both ends as described above.
Encoder & Communications Cabling
If encoder connections or communications cables are used, the wiring
must be separated from power cabling. This can be accomplished
with carefully routed, shielded cable (ground cable shield at the drive
end only) or a separate steel conduit (grounded at both ends).
Discrete Control and Signal Wiring
The control and signal wiring must be grounded at a single point in
the system, remote from the drive. This means the 0V or ground
terminal should be grounded at the equipment end, not the drive end.
If shielded control and signal wires are used, the shield must also be
grounded at this point.
If the control and signal wires are short, and contained within a
cabinet which has no sensitive circuits, the use of shielded control and
signal wiring may not be necessary, but is always recommended.