Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE - Manual (Page 193)

INSTALLATION 8-7
1557-UM050F-EN-P – June 2013
Figure 8.4 – Typical Drive Floor Plan
The drive isolation switch and contactor may be located remotely from the drive, in which case; Kirk key
interlocks or their equivalent must be used to interlock the drive and its isolating switch. It is the
responsibility of the installer to ensure that all required interlocks are installed and function properly.
Grounding Practices
The purpose of grounding is to:
A) Provide for safety of Personnel.
B) Limit dangerous voltages on exposed parts to ground.
C) To facilitate proper over current device operation under ground fault conditions.
D) To provide for electrical interference suppression.
IMPORTANT: Generally, grounding should be in accordance with the Canadian Electrical Code (CEC) or
National Electrical Code (NEC) and local codes.
Each power feeder from the substation transformer to the drive must be provided with properly sized
ground cables. Simply utilizing the conduit or cable armor as a ground is not adequate. The conduit or
cable armor and ground wires should be bonded to ground at both ends. Each transformer enclosure
and/or frame must be bonded to ground at a minimum of two locations.
NOTE: 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 20 feet 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.