Siemens GM-SG - Electrical Connections: Buswork; Bus Bar Description and Material; Bus Joints and Connections Guide

Electrical
Connections
Figure
27
.
Barrier
F
is located
in
the
upper
portion
of
the lower
primary
compartment
and
is
readily
accessible
from
the
front of
the
section
.
For
some
arrangements
it
may
be
necessary
to
remove
items between the
main bus
barriers and the
rear
of
the
unit
in
order
to
gain
full
access
.
After
completion
of
the bus
assembly
and
insulation
,
these
items
should be
reassembled
in
reverse
sequence
.
Molded
plastic
insulation boots
for
bus bar
joints
are
normally
shipped
factory
installed
at
shipping
splits
.
Note
their location
and
orientation
,
so
they
may
be
properly
reinstalled
after
the
joint
is bolted
together
.
Carefully
remove
and
save
the
nylon
hardware and the boot
.
All
surfaces
must
be
free
of
dust
,
dirt
or
other
foreign
material
.
Do
not
use
any
abrasive
cleaner
on
plated
contact
surfaces
.
Cleaning
is
normally
not
necessary
and should
not
be done unless
parts
are
badly
tarnished
.
If
cleaning
is
necessary
,
use a
mild
cleaner and
thoroughly
rinse the
parts
to
remove
all residue
.
Keep
cleaning
agent
off
insulation
.
Before
assembling
any
bus bar
joint
,
check that the
bar is inserted
through
bus
supports
(
when
required
)
and interunit bus
supports
,
including
neoprene
grommets
and insulator
rings
(
inserts
)
where that
option
is
furnished
.
Grommets
(
as
shown
in
Figure
21
)
are
used
to
support
the bus
bars
in
the insulator
rings
(
inserts
)
.
Observe
the
factory
positioning
of
these
grommets
when
connecting
at
shipping
splits
to
insure that bus bars
will
line
up
properly
.
Normally
,
the bus bar is
oriented
in
the
insert
toward the
front
.
Neoprene
grommets
are
to
be installed centered
in
the insert
.
Also observe the
relationship
of
the bus bar
to
the
circuit breaker riser
(
i
.
e
.
,
whether bus bar is
in
front
of
,
or
behind
,
the riser
)
.
Maintain this
relationship
when
connecting
bus bars
.
Spacers
are
required
in
some
bus
joint
connections
.
Assemble all
joints
with
the
parts
dry
.
Do
not
use
any grease
or
"
no
-
oxide
"
product
.
Bus Bar
Bus
bar is
furnished for
connection between
many
of
the
high voltage
items
within
the
switchgear
enclosure
,
such
as
main bus
,
circuit breakers
,
cable termination
pads
,
and
for
certain connections
to
auxiliary
cells
(
e
.
g
.
,
voltage
transformers
,
control
power
transformers
,
or
rollout
fuse
tray
for
control
power
transformer
primary
fuses
)
.
Cables
are
provided
for
some
connections
to
primary
disconnect assemblies
for
voltage
and
/
or
control
power
transformers
and
for
connection
to
surge
arresters
or
surge
limiters
.
Standard
bus bar
material is
copper
with
silver
-
plated
joints
for
electrical connections
.
Copper
bus
,
with tin
plated
joint
surfaces
,
is also available
.
Bus
bars
are
insulated
with
an
epoxy
insulation
applied
by
a
fluidized
bed
method
.
Bus
bar
joints
are
insulated
with
molded
insulation boots
(
where
a
boot is available
)
or are
taped
.
Additional insulation is
provided
by
clearance
through
air and bus
supports
.
In
some
locations
,
standoff
insulators
are
used
.
Glass
polyester
molded interunit bus
supports
are
provided
as
standard
.
Porcelain
or
epoxy
insulator
rings
(
inserts
)
mounted
in
glass polyester
supports
,
porcelain
or
epoxy
standoff
insulators and
/
or
porcelain
primary
disconnect
bushings
may
be
furnished
as
options
.
1
.
2
.
3
.
A
DANGER
Hazardous
voltage
.
Will
cause
death
,
serious
personal
injury
,
and
property
damage
.
Do
not
contact
energized
conductors
.
De
energize
and
ground
high voltage
conductors
before
working
on or near
them
.
4
.
Bus
Joints
When
a
switchgear
lineup
is
split
for
shipping
purposes
,
the
primary
bus and
ground
bus
connections
must
be
made when
installing
the
switchgear
.
These bolted
connections
are
relatively
simple
to
make
.
Refer
to
Figures
17
and
18
and these instructions
.
The bus
bars and
connection hardware
for
joining
the
groups
together
are
normally
shipped
mounted
on a
bracket
in
one
of
the units involved
in
the connection
.
When this is
not
possible
,
the connection bars and
hardware
will
be
shipped
in
a
separate
package
,
and
will
be listed
on
the
"
Accessories
"
drawing
.
(
This
drawing
is listed
on
the
"
Reference
Drawing
List
"
)
.
Access
to
the main bus
from
the cable termination
area
is achieved
by removing
the main bus
compartment
barrier
(
R
in
Figure
27
)
which
separates
the main bus
from
the cable
area
.
If
access
to
the main bus is
impeded
by
installed
equipment
,
access
to
the main
bus
can
usually
be
achieved
by
removal
of
barrier
F
,
shown
in
5
.
NOTE
:
All
main bus hardware
furnished
is
plated
high strength
steel
.
Cap
screws are
1
/
2
-
13
SAE Grade
5
.
Do
not
substitute
with
smaller
or
lower
grade
hardware than
supplied
.
6
.
Use
proper
hardware
.
Heavy
flat
washers
are
used
on
both sides
of
the bus
bar
joint
-
under
the
cap
screw
head
as
well
as
under the
nut
and lock
washer
.
These washers insure
an
evenly
distributed
force
around each bolt
,
producing
a
low
resistance
joint
.
Proper
torque
value
produces
a
joint
of
adequate
pressure
without
cold
flow
.
Refer
to
Figure
20
.
23
Courtesy of NationalSwitchgear.com