GE AKD-10 Application Manual page 6

• Breaker insertion and withdrawal interlocks
ΠInterlocks prevent racking of the breaker in or out when the breaker contacts
are closed.  Breakers are trip free when not in the CONNECT or TEST position.
A superior bus system offers different levels of protection:
• Fully tin-plated copper bus
Fully tin-plated copper main and riser bus is a standard feature on AKD-10
equipment. Tin plating provides superior corrosion protection, especially for
application in the pulp and paper and waste treatment industries where corrosive
agents routinely exist. GE's bus bars are tin-plated after forming and punching
to ensure completely plated bolt holes and bar edges. Sliding contact surfaces,
such as breaker stab tips, are fully silver-plated. Fully silver-plated bus is available
as an option.
• Bus system
Bare bus is provided as standard on AKD-10 switchgear. In this configuration,
there are no covers to remove, so all bus connections are easily accessible for
maintenance. Note that a horizontal isolation barrier is provided between the vertical
buses at every main and tie breaker for added safety in the event of a fault. An insu-
lated/isolated bus system that fully insulates the horizontal main bus with a fluidized
epoxy coating and isolates each phase of the vertical riser bus is available as an
option. Accessibility to main bus joints is provided by replaceable covers and no live
connections are reachable from the rear except the breaker load side terminals. Bus
compartmentation is also available as an optional feature on AKD-10 switchgear.
Vertical and horizontal buses are isolated from the cable compartment by glass
reinforced polyester barriers.
The breaker compartment is designed to provide operator and
system safety options:
• Isolated breaker compartment (standard)
Each circuit breaker is located in a completely enclosed ventilated compartment
with grounded steel barriers to minimize the possibility of fault communication
between compartments. A breaker position switch is optionally available.
• Safety shutters
Safety shutters are optionally available in breaker compartments. They protect
operators from accidental contact with live conductors when the breaker is
withdrawn. Safety shutters are provided as a standard feature on main and tie
breakers in multi-source substations.
• Defeatable door interlock
This option prevents inadvertent opening of the compartment door unless the
breaker is in the TEST or DISCONNECT position. A provision is made for authorized
defeat of interlock.
• Padlockable door latch
This optional feature enables padlocking of the door latch in order to prevent
unauthorized entry into the breaker compartment.
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