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SEECO
phase-over-phase GOABS® switches are designed specifically for switching
applications in transmission environments. They provide economical
sectionalizing, and tap and tie switching points for circuit control.
Mounted on a single pole structure in the line, their use can minimize
line right-of-way requirements and significantly reduce the costs of land
and equipment associated with conventional substation switching.
Phase-over-phase GOABS® utilize
side-break style switches, mounted horizontal upright on aluminum support
structures. The switch is designed for maintenance-free operation in
severe environmental and operating conditions. The operating effort
to open and close the switch is minimal, even at higher voltages; no
slamming is ever required. The switch is positively toggled when in
the fully closed position, so the switch stays closed under adverse
conditions, such as excessive pole deflection, vibration, and galloping
conductors, without the use of blade locks or other latching devices.
The current-carrying path is all
copper with silver contact buttons, which provide a silver to copper
current transfer; no aluminum is ever used in the current path. The
current ratings are based on a 30 degree temperature rise. Hinge and
jaw assemblies are high pressure devices and are permanently sealed,
requiring no maintenance over the life of the switch. The design of
the jaw (female) contacts is very forgiving, allowing a substantial amount
of pole/frame structure movement and deflection without diminishing
contact pressure or effectiveness of current transfer.
The provision of support frames
eliminates the need for pole cross arms or braces, and the use of aluminum
provides a beneficial combination of light weight and high strength, which
reduces pole structure design requirements and cost. Frames have
welded construction which provides a rigid, stable platform to
assure proper switch operating performance.
Switches rated 69 kV and below
will mount on any suitable structure; switches rated 115 kV and above will
mount on steel, concrete, or laminated wood poles.
Tie and Tap Switching
Two-way and three-way
phase-over-phase switches employ a multiple-switch concept where
individual switch pole units are arranged in an integral design, sharing
insulators, interrupters, and other switch components. Because
components are shared, the cost of switching becomes proportionally less
expensive when compared to other conventional switch configurations.
In addition, the combining of
two or three switches into one "bundle" provides a single location for tap
or tie circuit control, whether local, remote, or automatic. This
facilitates the addition and use of automation equipment, such as motor
operators, rtu's, and line sensors, which support switch operation through
supervisory control or auto-sectionalizing. Like the sharing of
switch components, the sharing of automation equipment makes the cost of
control proportionally less expensive.
Interruption Devices
High-speed, snap-out arcing
horns are standard equipment on all type "G" GOABS®. They are
suitable for interruption of line charging and transformer magnetizing
currents.
The addition of SEECO MONORUPTR®
vacuum interrupters to phase-over-phase switches provides full load-break
capabilities, allowing the switch to be operated under conditions that
exceed the capabilities of conventional arcing horn devices. One
interrupter unit (column) is used per phase and is mounted on the
stationary, non-rotating insulator; the interrupter unit is then shared by
each way of the switch. Interrupter switches allow breakers to be
reserved for their intended duty of fault interruptions, reducing breaker
wear, and reducing or eliminating service interruptions for switching
purposes.
For more complete information on
product features and functions, please view the Construction Details
page.
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