SECTION 16323
LOW VOLTAGE FRONT ACCESSIBLE MAIN SWITCHBOARD
PART 1 - GENERAL
1.01
General: Provide low voltage main switchboard, complete, as indicated, specified
and required per Contract Documents.
1.02
Work In This Section: Principal item includes 480-volt service switchboard.
1.03
Other Applicable Sections: Requirements of Division 1 and Section 16050 apply
to work of this Section.
1.04
SUBMITTALS
A.
Procedures: Refer to Division 1.
B.
Requirements: In addition to the requirements of Section 16050, submittal
material shall include six copies of descriptive data for all products and
materials including, but not limited to, the following:
1.
Descriptive Data: Before final acceptance of the work, Contractor
shall deliver to the Architect an Operating and Maintenance
Manual in flexible binder and one complete set of sepia
transparencies of all shop and circuit drawings, wiring schedules,
and one-line overall diagrams of the switchboard. In addition, a
copy of the approved system parts List shall be included in each
manual.
2.
Shop Drawings: Submit drawings and specifications for all parts,
components and assemblies under this Section. Submit complete
coordination curves for approval.
PART 2 - PRODUCTS
2.01
GENERAL
A.
Main switchboard shall be complete, unitized, integral- assembly, metalenclosed, dead-front, dead-rear, front accessible, indoor type.
B.
Switchboard shall be General Electric, Westinghouse, or Siemens.
C.
Ratings: Ratings shall be not less than required by the NEC and not less
than indicated on the drawings. Short- circuit current ratings shall be not
less than the maximum short-circuit currents available where switchboard
is being installed, as herein specified.
D.
Arrangements: Switchgear shall conform to the arrangements and details
indicated on the drawings.
E.
Coordination: Coordinate all components and their arrangements
electrically and mechanically. Coordinate all circuit entrances including
method of entrance and connections.
F.
Design: To withstand the mechanical stresses caused by rough handling
during shipping in addition to the electrical and mechanical stresses which
will occur during operation.
G.
Interlocks: Incorporate interlocking, as indicated on the drawings, and as
required for the safe operation. All hinged doors shall have locks.
H.
Assemblies: Assemble, connect and wire switchboard at the factory so
that minimal work will be required at the construction site.
I.
Finish: Thoroughly clean, phosphatize and paint metal surfaces at factory
with primer and enamel or lacquer, light gray finish.
J.
Switchboard Enclosures: Steel assemblies, adequately braced to ensure
rigidity and alignment. Sheet steel shall be standard gauge, stretcherleveled. Holes for connecting adjacent sections shall be die-pierced to
ensure alignment and provide for future extensions. All bolts, nuts,
washers and fittings shall be rustproof metal. Provide adequate space
within each enclosure for equipment and cables.
K.
Busing and Connections: All buses, including neutral, shall be copper or
aluminum sized for continuous ratings and braced to withstand short
circuit stresses as herein specified. All joints shall be silver-plated and
connections shall be made with a minimum of two high-strength bolts with
spring washers. Buses shall be supported on high-strength, nonhygroscopic insulators. Suitably sized ground bus shall extend through all
sections with cable connectors in each section.
L.
Identification: Provide engraved nameplate for each circuit breaker stating
trip rating and load supplied. Provide breaker frame size and type on
nameplate unless readily identifiable without removing switchboard cover.
Provide main unit nameplates. Attach nameplates with self tapping
screws.
M.
Auxiliary Wiring: Necessary fuse blocks and terminal blocks within the
switchboard shall be furnished when required. All groups of control
wires leaving the switchboard shall be provided with terminal blocks with
suitable numbering strips. All hardware used on conductors shall have a
high tensile strength and an anti-corrosive zinc plating.
N.
Switchboard 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 without the use of floor sills.
O.
Individual shipping sections shall be designed for bolting together at
installation site. All necessary bolting hardware as well as main bus
splices shall be supplied between adjacent shipping sections.
P.
Adequate conduit space shall be provided to meet NEC requirements.
Q.
All terminals shall be two hole compression type suitable for copper cable
of sizes indicated.
R.
Minimum short-circuit bracing shall be 50,000 AMP unless indicated
otherwise on Drawings.
S.
A-B-C Type Bus Arrangement: Left-to-right, top-to-bottom, and front-torear, as viewed from the front, shall be used throughout.
T.
Main horizontal bus bars shall be mounted with all three phases arranged
in same vertical plane. Provide full capacity neutral.
U.
All vertical sections shall align rear with depth as shown on Drawings for
mounting against wall.
V.
All circuit breakers, mains and feeders shall be front accessible. Lock-off
capability shall be provided on all breakers.
W.
Cable Supports: Provide brackets in all cable enclosure compartments for
cable supports.
2.02
2.03
MOLDED CASE CIRCUIT BREAKERS
A.
Breakers with solid-state trip elements shall be equipped with complete
with built-in current transformers and flux transfer shunt trip. Breakers
shall have easily changed trip rating plugs with trip rating as indicated on
the drawings. Rating plugs shall be interlocked so that they are not
interchangeable between frames and interlocked such that breaker cannot
be latched with rating plug removed. Breaker shall have built-in test
points for testing long, short delay, instantaneous and ground fault
functions of the breaker by means of a 120-volt operated test kit.
B.
Breakers rated 1,600 AMP through 3,000 AMP shall be 100% rated.
C.
Solid-state trip elements shall have independently adjustable long, short
delay pickup with adjustable instantaneous pick-up for high magnitude
faults.
D.
Provide test kit capable of testing all breakers 600 AMP and above.
E.
Provide lock-off for all breakers.
GROUND FAULT
A.
2.04
TRIP INDICATORS
A.
2.05
Provide ground fault protection on all main breakers with adjustable pickup from 20% of trip rating to 100% of trip rating, but not exceeding 1,200
AMP; ground fault time delay shall be adjustable 0.1 to 0.5 seconds.
Provide neutral ground fault current transformer, where required. Supply
integral ground trip on all static trip breakers and ground relay on all
thermal magnetic breakers.
Provide ground overcurrent resettable trip indicators for all main breakers
through 3,000 AMP frames, equipped with ground fault relaying.
INSTRUMENTATION
A.
Provide current transformers, ammeter, ammeter switch and wattmeter for
main breakers. Provide voltmeter, potential transformers and voltmeter
switch for main bus. Provide test blocks, for portable recording ammeter
and voltmeter. Include 4-20 mA transducers for remote indication of 3
phase amperes, 3 phase watts and single phase volts. Contractor, as an
option, may furnish a Westinghouse Type IQ microprocessor metering
device in lieu of ammeter, ammeter switch, voltmeter, voltmeter switch
and wattmeter.
B.
Power Company Metering: Provide bused metering compartments in
accordance with the applicable Utility standards.
PART 3 - EXECUTION
3.01
FACTORY ASSEMBLY AND TESTS
A.
3.02
LOW VOLTAGE
A.
3.03
Each multi-unit section shall be shipped completely assembled and shall
be equipped with shipping angles to permit handling with a crane.
Installation work shall be reduced to a minimum.
INSTALLATION
A.
3.05
Main circuits will be given a dielectric test of 2,200 volts for one minute
between live parts and ground and between opposite polarities. Wiring
and control circuits will be given a dielectric test of 1,500 volts for one
minute between live parts and ground.
SHIPPING
A.
3.04
Switchboard shall be completely assembled, wired, adjusted and tested at
factory. After assembly, complete switch-board shall be tested for
operation under simulated service conditions to assure accuracy of wiring
and functioning of equipment.
Switchboard shall be securely bolted to concrete floor. Shipping sections
shall be electrically connected with connectors furnished with the gear.
CHECK-OUT AND TESTING
A.
Switchboard manufacturer shall provide breaker and/or fuse coordination
curve showing coordination between upstream and downstream
overcurrent protective devices. Manufacturer's service representative shall
test and set breaker and/or relay trip devices and submit written report.
**END OF SECTION**