Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive (A Frame) - ForGe Control - Manual (Page 48)

48 Rockwell Automation Publication 7000A-UM200C-EN-P - June 2014
Chapter 2 Drive Installation
Figure 34 - Ground Connection Diagram with Isolation Transformer
Figure 35 - Ground Connection Diagram with Line Reactor
Each power feeder from the substation transformer to the drive must be provided
with properly sized ground cables. Utilizing the conduit or cable armor as a
ground is not adequate.
Note that if a drive isolation transformer is used, the WYE secondary neutral
point should not be grounded.
Each AC motor frame must be bonded to grounded building steel within 6 m
(20 ft) of its location and tied to the drive's ground bus via ground wires within
the power cables and/or conduit. The conduit or cable armor should be bonded
to ground at both ends.
ISOLATION
TRANSFORMER AC
MOTOR
U (T1)
V (T2)
W (T3)
2U
2V
2W
GROUND BUS
Connected to the neutral point
of the output capacitor
OUTPUT
GROUND
NETWORK
AC
MOTOR
U (T1)
V (T2)
W (T3)
2U
2V
2W
GROUND BUS
AC LINE
REACTOR
TRANSFORMER
Connected to the neutral point
of the output capacitor
GROUND
FILTER
AC
MOTOR
U (T1)
V (T2)
W (T3)
2U
2V
2W
GROUND BUS
AC LINE
REACTOR
TRANSFORMER
Connected to the neutral point
of the output capacitor
GROUND
FILTER