Nominal voltage (kV)............................................[_____].
Rated maximum voltage (kV)......................................[_____].
Rated continuous current (A)....................................[_____].
Three-second short-time current-carrying capacity (kA)..........[_____].
BIL (kV)........................................................[_____].
2.10
METERING AND PROTECTIVE DEVICES
2.10.1
Circuit Breakers, Low-Voltage
2.10.1.1
Low-Voltage Power Circuit Breakers
a.
Construction
Low-voltage power circuit breakers shall conform to IEEE C37.13, ANSI C37.16,
and NEMA SG 6 and shall be three-pole, single-throw, stored energy,
[manually] [electrically] operated, with drawout mounting. Solid-state
trip elements which require no external power connections shall be
provided. Circuit breakers shall have an open/close contact indicator,
primary disconnect devices, and a mechanical interlock to prevent making or
breaking contact of primary disconnections when the circuit breaker is
closed. Control voltage shall be [[24] [48] [125] V dc] [120 V ac] [as
indicated]. The circuit breaker enclosure shall be suitable for its
intended location.
b.
Ratings
Voltage ratings shall be not less than the applicable circuit voltage.
Circuit breakers shall be rated for 100 percent continuous duty and shall
have trip current ratings and frame sizes as shown. Nominal voltage
ratings, maximum continuous-current ratings, and maximum short-circuit
interrupting ratings shall be in accordance with ANSI C37.16. Tripping
features shall be as follows:
1. Long-time current pick-up, adjustable from 50 percent to 100
percent of sensor current rating.
2.
Adjustable long-time delay.
3. Short-time current pick-up, adjustable from 1.5 to 9 times
long-time current setting.
4.
Adjustable short-time delay.
5.
[Short-time I2t switch.]
6. Instantaneous current pick-up, adjustable from 1.5 to 9 times
long-time current setting.
7. Ground-fault pick-up, adjustable from 20 percent to 60 percent
of sensor rating, but in no case greater than 1200 amperes.
Sensing of ground-fault current at the main bonding jumper or
ground strap shall not be permitted. [Zone-selective interlocking
shall be provided as shown.]
SECTION 16375A
Page 38
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