Rockwell Automation 6000 PowerFlex Medium Voltage Variable Frequency Drive Installation Instructions - Manual (Page 46)

46 Rockwell Automation Publication 6000-IN006A-EN-P - April 2014
Chapter 3 Drive Electrical Installation
Control Signal Wire Shield Grounding
Guidelines for Drive Signal and Safety Grounds: when using interface cables
carrying signals, where the frequency does not exceed 1 MHz, for
communications with the drive, follow these general guidelines:
• Ground screen mesh around the entire circumference, rather than forming
a pigtail grounded only at one point.
• For coaxial cables with a single conductor surrounded by a mesh screen,
ground the screen at both ends.
• When using a multi-layer screened cable (that is, a cable with both a mesh
screen and a metal sheath or some form of foil), there are two alternative
methods:
–
Ground the mesh screen at both ends to the metal sheath. The metal
sheath or foil (known as the drain) should, unless otherwise specified,
be grounded at one end only, again, as specified above, at the receiver
end or the end that is physically closest to the main equipment ground
bus
– Leave the metal sheath or foil insulated from ground, and ground the
other conductors and the mesh cable screen at one end only, as stated
above.
Grounding provisions for control signal wiring is shown in Figure 26 .
Figure 26 - Vertical Ground Bus in LV Cabinet
Vertical Ground Bus
Provisions for Grounding Control
Signal Wiring Shields, etc.
Ground Bus