GE Industrial Solutions Entellisys Installation - Manual (Page 36)

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Entellisys Low Voltage Switchgear
Chapter 4. Equipment Installation
The ground bus is mounted directly on the rear upright
channels.
NOTE: It is particularly important that the ground bus be
connected first since it provides an integral ground for all
the equipment. It must also be connected to the station
ground prior to proceeding with the installation.
NOTE: Il est particulièrement important que la barre
omnibus de mise à la terre soit branchée en premier, étant
donné qu’elle fournit une mise à la terre intégrale à tout
l’équipement. Elle doit aussi être branchée à la mise à la
terre du poste avant de procéder à la installation.
A 4/0 AWG cable connector is located in the bottom of the
transition section (or in the incoming line compartment if a
transition section is not included) for terminating the
purchaser's cable connection to ground. The specific location
of the station ground connection is shown on the site floor
plan drawing and in the frontview drawings supplied with
the equipment. All grounding of the switchgear should be in
accordance with National Electrical Code.
Fig. 4-9. Plan view of ground bus splice installation
Fig. 4-9 illustrates the installation of the ground bus splice
plate across a shipping split. In addition to the bolted
fastening of the splice plate to the two ends of the ground
bus, self-tapping 1/4-20 bolts pass through the splice plate
and ground bus stubs, and thread into the equipment frame.
These bolts should be fastened with a torque of 7-9 ft-lbs.
If a GE transformer (rated above 750 kVA) is present in the
line-up, a ground bar located in the transition compartment,
Fig. 4-10, is provided for connection of the transformer
ground pad to the equipment ground termination point.
Fig. 4-10. Flange opening on a transition section to a GE transformer
(above 750 kVA)
As shipped, the ground bar is mounted so it does not protrude
beyond the outer surface of the equipment. When the
equipment is installed in its final location, the ground bar
must be reassembled using the outer bolt holes in the
horizontal ground bus spanning the width of the transition
compartment. In this mounting location, the offset portion of
the ground bar will permit connection to the transformer
ground pad with the 1/2-13 bolt assembly supplied with the
switchgear equipment. If an optional floor plate is supplied
for the transition compartment, it will be necessary to remove
the floor plate to permit relocation of the ground connection
bar.