GE Industrial Solutions Entellisys Low Voltage Switchgear - Manuel (Page 18)

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piece, it can be split into two or more shipping sections at the
factory. The individual shipping splits require both mechanical
and electrical connections between sections to be made in the
field. At these shipping splits, provisions are made for bolting all
buses and making the necessary electrical and mechanical
connections. These are described in Chapter 4 of this publication.
On main and tie breakers, the bus area, is divided into an upper
and lower section by a glass reinforced polyester isolation barrier.
For typical unit substation main circuit breakers, the upper section
contains the incoming line bus. The lower section of the bus area
contains the load side main bus (protected by the main breaker)
which feeds all sections of the switchgear equipment. Similarly,
barriers at tie breakers isolate the two main bus sections from
each other.
1.
Incoming cable connection
2. Isolation barriers
3. Main horizontal bus connections
Fig. 3-14. Main breaker arrangement
Insulated/Isolated Bus System
A bus insulation system, Fig. 3-15, that fully insulates each phase
of the horizontal main bus and isolates each phase of the vertical
bus, is optionally available for Entellisys switchgear when
specified. With the INSULATED/-ISOLATED BUS system, there are
no live connections accessible in the rear of each feeder section
except the cable lugs or busway termination bars.
1. Vertical riser bus covers
2. Run-backs to feeder cables
3. Horizontal main bus
4. Upper neutral bus with 4 th wire
Sensors
Fig. 3-15. Insulated/Isolated-Bus system
A vertical barrier (2), Fig. 3-16, between the transition section (1)
and the first breaker section is always furnished.
The buswork in the device/auxiliary/transition sections is not
insulated at the termination points to the other connected
equipments such as transformers, busway, or existing equipment.
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