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3. The trip units for the main and tie 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 (with optional
Target Module).
d. Trip targets for overload, short circuit <and ground
fault> (with optional Target Module).
e. Adjustable short time pickup and delay, with three
delay bands, and switchable I
2
t ramp.
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.>
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 (with optional
Target Module).
d. Trip targets for overload, short circuit <and ground
fault> (with optional Target Module).
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.>
5. 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.>
MicroVersaTrip Plus
™
and MicroVersaTrip PM
™
1. Each circuit breaker shall be equipped with a protective
trip unit system to open the breaker for overloads, short
circuits <and ground faults> as specified in the following
subparagraphs. The protective trip unit system shall consist
of a solid-state, microprocessor-based trip unit, current
sensors, trip actuator and interchangeable rating plugs.
2. As a minimum, the trip unit shall have the following features
and functions:
a. The housing shall be a metallic enclosure to protect
against magnetic interference, dust and other
contaminants.
b. The protective system shall have reliable programmable
controls with repetitive accuracy and precise unit settings.
c. All current sensing shall employ true rms technology for
detecting overloads, <short time> overcurrent conditions,
<and ground fault conditions>.
d. A high contrast, liquid crystal display - LCD - unit shall
display settings, trip targets, and the specified metering
displays. The trip unit shall be equipped with long-life
lithium batteries - with automatic time delay shut-off
feature - to provide both programming and observation
of trip targets or other functions when the breaker is
de-energized.
e. A multi-button keypad to provide local setup and read-
out on the LCD of all trip settings, metering values, and
trip targets.
f. UL listed and CSA certified field installable, interchangeable
rating plugs. It shall not be necessary to change or remove
the trip unit to change the trip rating. Rating plugs shall
contain rejection features to prevent installation of a
plug with an incorrect current sensor rating.
g. Integral test jack for connection of a battery pack or
test kit to the breaker.
h. (When specified) the ground fault function shall contain a
memory circuit to integrate low level arcing fault currents
with time to sum intermittent ground fault current spikes.
i. A cover with provisions for sealing the rating plug, the
trip unit, and the “ENTER” key on the protective trip unit
to make the installation tamper-resistant. All trip unit
settings, ratings, and target information shall be capable
of being viewed with the cover in place.
j. The unit shall be dual-rated for both 50Hz and 60Hz
operation. Noise immunity shall meet the requirements
of ANSI Standard C37.90.2.
k. The trip unit shall have an integral, resettable trip counter to
record the number of long time, short time, instantaneous
and ground fault trips. Trip target information shall include
fault current magnitude and phase for long time and short
time trips and fault current magnitude (as a function of
the sensor rating) for ground fault trips. When the trip unit
is supplied with additional protective relay functions,
the display shall also provide target indication for each
type of protective relay trip.
l. The trip unit shall display trip targets for longtime, short
time, instantaneous and ground fault trips.
m. All trip unit settings and trip target information shall be
stored in nonvolatile memory.
3. The trip units for the main and tie 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.
f. SELECT ONE OF THE FOLLOWING IF GROUND FAULT
PROTECTION IS REQUIRED:
