b.
Ground bus: Provide a copper ground bus sized for full short-circuit
capacity. Secure ground bus to each vertical structure and extend
ground bus the entire length of switchgear. Include provisions for
making the station ground connections.
c.
DC bus: Provide an insulated copper bus or wire extending the entire
length of switchgear. Bus shall be rated 100 amperes at 125 Vdc. Wire
shall be No. 6 AWG minimum.
d.
Each breaker compartment shall have provision for mounting up to four
sets of ANSI rated current transformers, two on line side and two on
load side of each breaker.
2.2.5.1
Circuit Breaker
Each [vacuum][SF6] circuit breaker shall be an electrically operated,
three-pole, circuit interrupting device rated as indicated at maximum
voltage of [_____] kV and [_____] kV BIL. Breaker shall be designed for
service on a [_____] kV system with a short-circuit capacity of not less
than [_____] [amperes symmetrical][MVA]. Rating shall be based on IEEE
C37.04 and NEMA C37.06. Breaker frame size shall be as indicated. Circuit
breaker shall be drawout-mounted with position indicator, operation
counter, auxiliary switches, and primary and secondary disconnect devices.
Circuit breaker shall be operated by an electrically charged, mechanically
and electrically trip-free, stored-energy operating mechanism. Provide for
manual charging of the mechanism and for slow closing of the contacts for
inspection or adjustment. Circuit breaker control voltage shall be [_____]
Vdc.
a.
Contacts: Silver-plated, multifinger, positive pressure, self-aligning
type for main drawout contacts.
b.
Each drawout breaker shall be provided with three-position operation.
The connected position and the test/disconnect position shall be
clearly identified by an indicator on the circuit breaker front panel.
1.
Connected position: Contacts are fully engaged. Breaker shall be
tripped before it can be racked into or out of this position.
2.
Test/disconnect position: Position shall allow for complete
testing and operation of the breaker without energizing the
primary circuit.
3.
Withdrawn (removed) positions: Places breaker completely out of
compartment, ready for removal.
2.2.5.2
Space Only Compartments
Provide fully equipped with busing, control switch, indicating lights, and
drawout breaker mounting and connecting straps to accommodate future
breakers. Provide compartments with doors.
2.2.5.3
Breaker Lifter
Provide a portable lifter rated for lifting and lowering circuit breakers
from two-high cubicles. Portable lifter shall have swivel casters in front
for ease of movement.
SECTION 16361N
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