GE AKD-10 Application Manual page 58

Grounding of the breaker frame to the switchgear shall be
maintained throughout the travel of the drawout mechanism.
Padlocking provisions shall permit locking of the breaker in
either the test or disconnected position. The drawout rails
shall accept up to three padlocks to preclude the unauthorized
installation of a circuit breaker into an empty cubicle.
<Compartment doors shall be capable of being padlocked.>
<Position switch with [2NO-2NC / 6NO-6NC] contacts shall
be provided.> <Shutters shall be supplied to cover breaker
primary line and load disconnects when the breaker <and
fuse carriage> is removed from its compartment on main
<and tie> breaker compartments of double ended substations
<and all feeder breakers>>. (Note that a 1600A frame fused
breaker with 2500A current limiting fuses does not allow the
use of a shutter)Each breaker compartment shall be equipped
with a steel auxiliary panel that shall be used for mounting
breaker control circuit fuses, pilot lights and breaker control
test switches. Direct access to these control circuit devices
shall be provided to facilitate routine maintenance and quick
and safe replacement of fuses and lamps without opening
the breaker cubicle door or panel. The auxiliary panel shall
contain an engraved breaker circuit nameplate, <pilot lights
for breaker open/closed indication> <fuses for breaker close
and trip circuits> <toggle switches for testing the breaker
close and trip circuits when the breaker is in the test position>.
Each breaker cubicle shall contain a rugged, positive rejection
system so that only the breaker frame for which the cubicle
was designed can be inserted.
When specified for future breaker, the compartment shall be
completely equipped for the future addition of a power circuit
breaker element including all specified electrical connections.
A re-usable metal barrier shall be provided for the opening
in the breaker compartment door. <Field convertible blank or
space compartments for [800/ 1600/ 2000] amp breakers
shall be supplied as specified or as shown on the drawings.
The space compartment shall have line-side bus connections
only. Load-side bus, drawout rails, secondary disconnects
and cubicle door with the breaker cutout shall be available
for field installation at a later date.>
Circuit breakers
Circuit breakers shall be individually mounted, drawout, low
voltage power circuit breakers. They shall meet the require-
ments of ANSI C37.13, C37.16, C37.17, C37.50, and shall be
listed and labeled to UL-1066 <and CSA C22.2.>
Circuit breakers shall be manually or electrically operated,
with features and accessories described in this specification.
Breakers shall have a maximum voltage rating of 635 Vac
(600 Vac for integrally fused breakers) and shall be rated to
carry 100% of the current rating of the breaker continuously.
Breakers shall have minimum interrupting ratings as shown
on the drawings.
Circuit breakers shall be metal frame construction. The
interrupting mechanism shall contain arc chutes constructed
to suppress arcs and cool vented gases. Interphase barriers
of insulating material shall be provided to isolate each pole
of the breaker.
Circuit breakers shall have true 30 cycle withstand capability
equal to its short time interrupting rating to help assure
selectivity with downstream devices and minimize nuisance
tripping when closing into high inrush loads. The breaker
shall not use a hidden instantaneous or making current
release to achieve its short time withstand ratings.
Breakers shall contain a true two-step stored energy mech-
anism providing quick-make, quick-break operation capable
of charging-after-close operation. It shall be possible to dis-
charge the closing springs without closing the main contacts.
Maximum closing time shall be 5 cycles at nominal control
voltage.
Each breaker shall include a flush-mounted, retractable
charging handle and close / open push buttons. The manual
charging handle shall be able to be used to complete charging
of an electrically operated breaker in the event control power
is lost during the charging operation. All manual control
operators (charge / close / open) for the breaker shall be
accessible from the front of the breaker when it is installed
in a cubicle, with the cubicle door closed. Complete breaker
operating status shall be available at the front of the breaker.
Indicators in the breaker escutcheon shall provide closing
spring status (charged / discharged), breaker main contact status
(open / closed) and breaker drawout position (connect / test
/ disconnect). Each breaker shall have standard padlocking
provisions, on the front of the breaker, to lock the breaker
open and mechanically trip-free. The padlock provision shall
accept up to three padlocks with 1/4 to 3/8" diameter shank.
The breaker trip unit shall be front mounted and shall allow
full access to all trip unit information including trip status,
pickup and delay settings, trip targets, and metering (where
applicable) without opening the breaker cubicle door. A
removable, sealable cover shall be provided over the trip
unit to limit access to the trip unit. Trip settings, metering
information and trip target information shall be accessible
with the sealable cover installed. Trip unit settings cannot be
changed unless the sealable cover is removed.
Each drawout breaker shall have provisions for up to 72
dedicated secondary disconnect points. All breaker control
circuits as well as inputs and outputs for the trip unit shall be
wired through the secondary disconnects. Secondary disconnect
points shall be self-aligning and automatically couple with
mating points in the breaker cubicle when the breaker is in
the "test" or "connect" position.
Circuit breakers shall employ a rejection system that will
only allow breakers of the correct ampere rating to be
installed in the cubicle. A breaker with a higher short circuit
interrupting rating shall be allowed to be mounted in the
cubicle provided it has the same frame rating. Integrally
fused breakers shall not be allowed to be mounted in a cubi-
cle intended for an unfused breaker. Breakers shall be
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