GE Industrial Solutions Entellisys Low Voltage Switchgear - Manuel (Page 26)

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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
on 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
Figure 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.
Transformer
Ground
connection bar