Rockwell Automation 1336T FORCE Series B - Manual (Page 35)

Chapter 2
Installation/Wiring
2–15
Grounding Refer to the grounding diagram on the following page. The drive must be
connected to the 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 connected 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, and to minimize the area enclosed by these paths.
Current carrying ground conductors must be separated. Control and signal
ground conductors should not run near or parallel to a power ground
conductor.
Motor Cable
The ground conductor of the motor cable (drive end) must be connected
directly to the drive ground terminal (PE), not to the enclosure bus bar.
Grounding directly to the drive (and filter, if installed) provides a direct
route for high frequency current returning from the motor frame and
ground conductor. At the motor end, the ground conductor should also be
connected to the motor case ground.
If shielded or armored cables are used, the same grounding methods should
be used for the shield/armor as well.
Encoder Connections
If encoder connections are required, they must be routed in grounded steel
conduit. The conduit must be grounded at both ends. Ground the cable
shield at the drive only.
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.