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A. TRAPEZE CONTACT
The trapeze contact consists of a silver plated
copper tube suspended by adjustable dropper rods,
quadruple or twin spacers, which are connected
to upper quadruple or twin ACSR conductor bus.
The complete assembly of sets of spacers, two
Aluminium dropper rods and one silver plated copper
tube totally form the Trapeze contact of Pantograph
Disconnector.
B. SCISSOR ASSEMBLY
The scissor assembly contains the four point
contacts of silver plated copper which makes contact
with the suspended copper tube of this trapeze
assembly. The copper contacts are mounted on the
Aluminium alloy extrusions assembled in the form
of a scissor. Current transfer contacts are provided
at the joints to ensure smooth transfer of current
from one moving part to the adjacent part. The
scissor arms on one side has counter balance springs
to ensure smooth operations. Current transfer
contact consists of a male copper contact on one
side and female contact finger assembly on the
opposite side. Corona rings are provided on the
scissor assembly at the upper contact point and
also at the joints in the scissor assembly.
C. MAIN FRAME ASSEMBLY
Main Frame assembly consists of the main frame
of the Pantograph Disconnector on which the pantograph
scissor are mounted. This assembly also has the
terminal pad at either end for connecting the
terminal connectors. The terminal pad is a plate
of aluminium alloy with four holes drilled on
it for fixing the terminal connector.
The main frame assembly also has the base plate
for mounting it on top of the solidcore support
insulator. It also houses the bell Crank and levers
connected to the down operating rod insulator
for the operation of the Disconnector.
D. SUPPORT INSULATOR
The support insulator is a soildcore insulator
which is primarily used to support the metallic
pole of the Pantograph Disconnector and also to
provide the required insulation between the live
parts and ground. An insulator corona ring is
provided on top of the insulator. The lower portion
of the support Insulator is mounted on to the
support structure column.
E. OPERATING ROD INSULATOR
While the support insulator explained earlier
gives the necessary rigid support for the metallic
part (main frame assembly and scissors), the operating
rod insulator is used primarily for operating
the pantograph scissors and for providing insulation
for the person operating the Pantograph. This
Insulator is also normally a solidcore insulator
of lesser diameter and cantilever strength when
compared to the support insulator. The upper end
of the insulator is connected to a bell crank
for operating the disconnector and the lower end
is connected to the operating mechanism through
a down operating pipe.
F. SUPPORT STRUCTURE
Wherever specified, support structure of tubular
types with necessary foundation bolts can be supplied.
Plates are welded on to this tubular support structure
fabricated out of welded sheet steel for mounting
the operating mechanism boxes. Operating mechanism
is mounted on to the structure on three plates
being bolted with three angles provided on the
mechanism box. The height of this support structure
can be varied to accommodate the height of Upper
and Lower bus heights as required by the purchaser's
layout and system.
G. OPERATING MECHANISM
Normal Drive for Pantograph Disconnector are
Motorised Operating mechanism, with Manual operating
provision for Emergency.
H. INTERLOCKS
The following interlocks are provided for the
Horizontal centre break disconnectors.
A Mechanical constructional interlock between
the Main and earth switch.
An electro-mechanical castell key type interlock
between Disconnector and earth switch where
earth switch is specified.
Electro mechanical castell Key Interlock between
electrical and manual operation in motor operating
mechanism.
Further Terminal are Provided in the electrical
control circuit of the motor operating mechanism
for customer to wire in external interlocks.
NOTE :
Pantograph disconnector can be supplied by
us with or without Earth switches. Earth switches
where supplied are mounted an adaptor fixed
to the support structure.
In case Pantograph Disconnector with double
earth switch are required, we can offer pantograph
disconnector with single earth switch additional
separately mounted busbar earth switch.
Pantograph type disconnectors are generally
single pole operated disconnectors and can be
electrically ganged to ensure three pole operation
of the disconnector.
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