60
1) <Adjustable ground fault pickup and time delay, with
three delay bands, and switchable I
2
t ramp.>
2) <Defeatable ground fault function with adjustable
pickup and time delay, with three delay bands, and
switchable I
2
t ramp.>
g. OPTIONAL: <Switchable short time / instantaneous
and ground fault protection.>
h. OPTIONAL (Select one if req’d): Zone selective interlocking
<for ground fault only> <for both ground fault and
short time>.
4. The trip units for feeder breakers shall include the following
protective functions:
a. Adjustable long time current settings.
b. Adjustable long time delay with four time delay bands.
c. Long time pickup warning indicator.
d. Trip targets for overload, short circuit <and ground fault>.
e. <Adjustable short time pickup and delay, with three
delay bands, and switchable I
2
t ramp> and/or
<adjustable instantaneous pickup>.
f. SELECT ONE OF THE FOLLOWING IF GROUND FAULT
PROTECTION IS REQUIRED:
1) <Adjustable ground fault pickup and time delay, with
three delay bands, and switchable I
2
t ramp.>
2) <Defeatable ground fault function with adjustable
pickup and time delay, with three delay bands, and
switchable I
2
t ramp.>
g. OPTIONAL: <Switchable short time / instantaneous
and ground fault protection.>
h. OPTIONAL (Select one if req’d): Zone selective interlocking
<for ground fault only> <for both ground fault and
short time>.
5. The trip units shall include the following metering functions,
which shall be displayed on the LCD:
a. Current, rms (A or kA), each phase 2.0% accuracy.
b. OPTIONAL (Note - if any of the following are included,
all will be included)
1) Voltage, rms (V), line-to-line or line-to-neutral, +/-
1.5% accuracy.
2) Energy (kWh, MWh, GWh), total, +/-3.5% accuracy,
user resettable.
3) Demand (kWh, MWh, GWh) over an adjustable time
period of 5 to 60 minutes, +/- 3.5% accuracy.
4) Peak Demand (kW, MW), +/- 3.5% accuracy, user
resettable.
5) Real power (kW, MW), line-to-line, line-to-neutral, +/-
3.5% accuracy.
6) Total (apparent) power (kVA, MVA), line-to-line,
line-to-neutral, +/-3.5% accuracy.
7) Frequency (Hz), +/-1Hz accuracy.
6. OPTIONAL: The trip unit shall include all of the following
protective functions. However, it shall be possible to disable,
by user programming, any combination of unwanted
protective functions.
a. Undervoltage, adjustable pickup - 50 to 90%,
adjustable delay - 1 to 15 seconds.
b. Overvoltage, adjustable pickup - 110 to 150%,
adjustable delay - 1 to 15 seconds.
c. Voltage unbalance, adjustable pickup - 10 to 50%,
adjustable delay - 1 to 15 seconds.
d. Current unbalance, adjustable pickup - 10 to 50%,
adjustable delay - 1 to 15 seconds.
e. Reverse power, selectable direction, adjustable pickup -
10kW to 990kW, adjustable delay - 1 to 15 seconds.
7. OPTIONAL: The trip unit shall include communication
capability as follows:
a. The trip unit, through dedicated secondary terminals
on the breaker, shall provide a communication port for
communication with and access to a remote computer
via the breaker supplier’s standard communication
network and protocol.
b. All metering, setpoints, protective trip counts, and
other event signaling shall be retrievable by the remote
computer.
8. Current sensors shall be mounted on the breaker frame
and shall use encapsulated construction to protect against
damage and moisture. <For ground fault protection of a
four-wire power system, a fourth - neutral current - sensor
shall be mounted in the cable compartment, and shall be
compatible with the phase current sensors.>
Devices
Switchgear will include all protective devices and equipment
as listed on drawings with necessary interconnection,
instrumentation and control wiring.
Wiring
Control wiring shall be #14 type SIS, enclosed in top and vertical
metal wiring troughs. Necessary fuse holders within the
switchgear shall be furnished when required. Terminal blocks
for external connections shall be heavy duty, molded, one-piece
type, rated 600volts, 50amps and shall be mounted in the
rear cable compartment, easily accessible, away from the
runbacks and cable terminals, and be provided with a bolted
steel cover to enclose the terminal blocks. Control wires leaving
the switchgear shall be terminated on terminal blocks with
suitable numbering strips. <Marking sleeves shall be provided
on all switchgear control wiring and shall be heat stamped with
the wire origin and/or destination information.> Interconnection
control wiring across shipping splits shall be accomplished
by terminal blocks in the control wiring trough on the top of
the equipment.
Ground bus
A copper [800A/1600A ] ground bus is to be provided and
secured to each vertical section structure. It shall extend the
entire length of the switchgear and be equipped with a 4/0
terminal for connection to purchaser’s ground system. A lug
strap shall be provided for feeder ground terminals.
Handling
Switchgear shall be provided with adequate lifting means and
shall be capable of being rolled or moved into installation
position and bolted directly to the floor.
