type, time delay, device [51G wired to a current transformer in
the source transformer neutral-to-ground connection] [51N,
residually connected], with current taps [[_____] to [_____]
amperes] [as indicated] and with characteristic curves that are
[definite time] [moderately inverse] [inverse] [very inverse]
[extremely inverse] [as indicated].
c.
Ground overcurrent relays for tie circuit breakers shall be
nondirectional, [induction] [solid-state] [microprocessor-based]
type, time delay, device 51N, residually connected, with current
taps [[_____] to [_____] amperes] [as indicated] and with
characteristic curves that are [definite time] [moderately
inverse] [inverse] [very inverse] [extremely inverse] [as
indicated].
d.
Phase overcurrent relays for feeder circuit breakers shall be
single-phase, nondirectional, [induction] [solid-state]
[microprocessor -based] type, time delay, device 50/51, with
instantaneous-current pick-up range [[_____] to [_____] amperes]
[as indicated], with time-delay-current taps [[_____] to [_____]
amperes] [as indicated] and with characteristic curves that are
[definite time] [moderately inverse] [inverse] [very inverse]
[extremely inverse] [as indicated].
e.
Ground overcurrent relays for feeder circuit breakers shall be
nondirectional, [plunger] [solid-state] [microprocessor-based]
type instantaneous, device [50GS wired to a ground sensor current
transformer] [50N, residually connected], with current pick-up
range [[_____] to [_____] amperes] [as indicated].
2.7.5.5
Directional Overcurrent Relays
Directional overcurrent relays shall be as follows:
a.
Directional phase overcurrent relays shall be single-phase,
[induction] [solid-state] [microprocessor-based] type with
instantaneous units. Phase relays, device 67, shall have an
instantaneous-current pick-up range [[_____] to [_____] amperes]
[as indicated], with time-delay-current taps [[_____] to [_____]
amperes] [as indicated] and with characteristic curves that are
[definite time] [moderately inverse] [inverse] [very inverse]
[extremely inverse] [as indicated].
b.
Directional ground overcurrent relays, device 67N, shall have an
instantaneous-current pick-up range [[_____] to [_____] amperes]
[as indicated], with time-delay-current taps [[_____] to [_____]
amperes] [as indicated] and with characteristic curves that are
[definite time] [moderately inverse] [inverse] [very inverse]
[extremely inverse] [as indicated].
2.7.5.6
Automatic Reclosing Relay
Relay, device 79, shall be of the three-phase, four-reclosure type,
providing immediate initial reclosure, and three time-delay reclosures.
Adjustable time delays shall be 10 to 60 seconds for reset and 0 to 45
seconds for reclosing. Units shall have instantaneous trip lockout after
any preset trip or when closing in on a fault. Auxiliary devices shall
provide for lockout when an associated circuit breaker is tripped after
three reclosures and automatically reset when an associated circuit breaker
SECTION 16311A
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