25
A K D - 20 A N D E NTE LLYS I S
LO W VO LTAG E S W I TC H G E A R
Insulated/isolated bus system
A bus insulation system, Fig. 3.23, that fully
insulates and isolates each phase of the horizontal
main bus and isolates each phase of the vertical
bus, is optionally available for AKD-20 and
Entellisys switchgear when specified. With the
INSULATED/ISOLATED BUS system, there are no
live connections accessible in the rear of each
section except the cable lugs.
A vertical barrier, Fig. 3.24, between the transition
section 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
equipment such as transformers, busway,
or existing equipment.
Insulation and isolation of the vertical riser bus
bars, Fig. 3.25, is provided by installing phase
isolation barriers (not shown) between the bus
bars and by the vertical bus barrier which covers
over the bus bars.
The phase isolation barriers and riser bus covers
are constructed from insulating material. Insulation
of the horizontal main bus bars is achieved by an
oven cured coating of epoxy.
The vertical/ horizontal bus bar joints are covered
with collars and caps (Joint Cap) held in place with
nylon thumb screws. The collars and caps are
constructed from insulating material.
1. Transition compartment
2. Barrier
3. Main incoming bus
4. Neutral bus
5. Ground bus
1. Vertical riser bus covers
2. Run-backs to feeder cables
3. Horizontal main bus
4. Upper neutral bus with 4th wire sensors
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Fig. 3.23
Insulated/isolated-
bus system
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Fig. 3.24
Transition section
—
Fig. 3.24
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Fig. 3.23
1
2
3
4
3
1
2
4
5
