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SECTION 16441 / SWITCHBOARD
PART 1 - GENERAL
1.01
RELATED DOCUMENTS
A.
Conform to Division 1 and other sections of this division.
B.
This Section is a Division 16 Basic Electrical Materials and Methods section and is a
part of each Division 16 section making reference to electrical supporting devices
specified herein.
1.02
SUMMARY
A.
Extent of switchboard work is indicated by drawings and schedules.
B.
Types of switchboards specified in this Section include the following:
1.
2.
Dead - Front Distribution.
Circuit - breaker switchboards.
1.03
SUBMITTALS
A.
Submit in accordance with General, Supplementary and Special Conditions.
B.
Product Data: Submit manufacturer's data on switchboards including, but not
limited to, voltages, number of phases, frequencies, and short-circuit and
continuous current ratings. Provide application data for main and branch
circuit-breakers, sections, main buses and basic insulation levels.
C.
Shop Drawings: Submit layout drawings of switchboards showing accurately scaled
basic equipment sections including auxiliary compartments, section components
and combination sections.
D.
Wiring Diagrams: Submit wiring diagrams for switchboards showing connections to
electrical power feeders and distribution branches. Differentiate between portions
of wiring that are manufacturer-installed and portions that are field-installed.
1.04
QUALITY ASSURANCE
A.
Codes and Standards:
1.
Electrical Code Compliance:
Comply with applicable local code
requirements of the authority having jurisdiction and that portion of the NEC
which pertains to installation and construction of switchboards.
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2.
3.
4.
5.
UL Compliance: Comply with applicable requirements of UL 489;
"Molded-Case Circuit Breakers and Circuit-Breaker Enclosures",and UL 891,
"Dead-Front Electrical Switchboards", pertaining to installation and
construction of switchboards. Provide switchboards and components which
are UL-listed and labeled.
IEEE Compliance: Comply with applicable requirements of IEEE Std. 241,
"Recommended Practice for Electric Power Systems in Commercial
Buildings", pertaining to switchboards.
ANSI Compliance: Comply with applicable requirements of ANSI standards
pertaining to switchboard assemblies.
NEMA Compliance: Comply with applicable portions of NEMA Stds Pub/No.
PB 2, "Dead-front Distribution Switchboards"; PB 2.1, "General Instruction for
Proper Handling, Installation, Operation and Maintenance of Dead-front
Distribution Switchboards Rated 600 Volts or Less", and SG-3, "Low-Voltage
Power Circuit Breakers", pertaining to switchboard assemblies.
1.05
DELIVERY, STORAGE, AND HANDLING
A.
Deliver switchboard and components properly packaged and mounted on pallets, or
skids to facilitate handling of heavy items. Utilize factory-fabricated type containers
or wrappings for switchboard and components which protect equipment from
damage. Inspect equipment to ensure that no damage has occurred during
shipment.
B.
Store switchboard equipment in original packaging and protect from weather and
construction traffic. Wherever possible, store indoors; where necessary to store
outdoors, store above grade and enclose with watertight wrapping.
C.
Handle switchboard equipment carefully to prevent physical damage to equipment
and components. Remove packaging, including the opening of crates and
containers, avoiding the use of excessive hammering and jarring which would
damage the electrical equipment contained therein. Do not install damaged
equipment; remove from site and replace damaged equipment with new.
1.06
SEQUENCING AND SCHEDULING
A.
Schedule delivery of switchboard equipment which permits ready building ingress
for large equipment components to their designated installation spaces. Coordinate
delivery of equipment with the installation of other building components.
1.
B.
Wall shall be painted at panel location prior to installation.
Coordinate the size and location of concrete equipment pads. Cast anchor bolt
inserts into pad. Concrete, reinforcement, and formwork requirements are specified
in Division 3.
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C.
Coordinate with other electrical work including raceways, electrical boxes and
fittings, and cabling/wiring work, as necessary to interface installation of switchboard
with other work.
PART 2 - PRODUCTS
2.01
MANUFACTURERS
A.
Available Manufacturers: Subject to compliance with requirements, manufacturers
offering switchboards which may be incorporated in the work include, and are
limited to, the following:
1.
2.
All switchboards, panels and components shall be of the same manufacturer.
Electrical switchboard with a capacity of 400 amperes or more shall be
Square D I Line for the base bid. An alternate bid may be submitted for
General Electric Spectra, Culter Hammer. Alternate bids are to state the
difference in price. General Electric Spectra shall have all spare spaces
filled with an equal amount of 225 amp and 400 amp circuit breaker
mounting modules with hole fillers and filler blanks.
2.02
EQUIPMENT SECTIONS AND COMPONENTS
A.
General: Except as otherwise indicated, provide switchboards and ancillary
components of types, sizes, characteristics, and ratings indicated, which comply
with manufacturer's standard design, materials, components, and construction in
accordance with published product information, and as required for a complete
installation.
B.
Enclosure Construction: The Switchboard shall be dead-front with front accessibility
required. The switchboard frame shall be of formed code gauge steel rigidly welded
and bolted together to support all cover plates, bussing and component devices
during shipment and installation. Steel base channels shall be bolted to the frame to
rigidly support the entire shipping section for moving on rollers and floor mounting.
Each switchboard section shall have a barriered bottom and an individually
removable top plate for installation and termination of conduit. The switchboard
enclosure shall be painted on all exterior and interior surfaces. The paint finish shall
be a medium light gray, ANSI #49, applied by the electro-deposition process over
an iron phosphate pre-treatment. All front covers shall be screwed on and
removable and all doors shall be hinged with removable hinge pins. Top and
bottom conduit areas shall be clearly indicated on shop drawings.
C.
Bussing: All main and vertical busses and connections thereto shall consist of 98%
conductivity copper electrical conductor grade copper bars rigidly mounted in heavy
insulating supports braces to withstand short circuit stresses as shown on plans.
Main busses shall be sized as indicated on the drawings and shall be full size for
the entire length. All contact surfaces of copper bars shall be silver plated. A
non-insulating ground bus shall be provided in all sections of the switchboard.
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Where future space is indicated bus bar shall be provided in the entire section of
the switchboard for mounting the breaker.
D.
Short Circuit Current Rating: The switchboard, as a complete unit shall be given a
single short circuit current rating by the manufacturer. Such ratings shall be
established by the actual tests by the manufacturer, in accordance with UL
specifications, on equipment constructed similarly to the subject switchboard.
E.
Main circuit breaker shall be of the molded case plastic type, 3-pole, manually
operated, stationary type, front connected, with adjustable long time and adjustable
instantaneous, ground fault protection, 100% rated. Frame size and trip unit shall
be as indicated.
F.
Main Circuit Breaker: Main circuit breaker shall be insulated case. Frame size and
trip unit shall be as indicated. Breaker shall be constructed from high dielectric
strength, glass-reinforced insulating material and include a solid state electronic
programmer and a positive action flux-shifting trip device. Breaker shall be for
100% continuous duty and shall have 65,000 amps AIC RMS SYM minimum
interrupting rating, with the following functions:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Continuous ampere control settings 0.5X, 0.7X, 0.8X, .85X, 0.9X, .95X and
1.0X.
Long time trip band control settings 2.5 through 20 seconds at six times the
continuous current setting.
Short time amperes trip point setting at 1.5X through 9X at a minimum of 8
points.
Short time delay settings 0.1 through 0.35 seconds.
Instantaneous amperes trip point setting at 1.5X through 10X at a minimum
of 8 points.
Ground fault trip point current settings in five steps 0.2X through 0.6X.
Ground fault delay time settings of 0.10, 0.21 or 0.35 seconds.
Zone selective with transformer circuit breaker.
Targets for overload, short circuit and ground.
G.
Breaker shall have a trip-free handle operating special arc resisting contacts in
effective arc quenchers. Each molded case breaker shall be rated for 40oC ambient
operation. Each breaker shall be stored energy trip mechanism type with a trip
push button.
H.
Breaker protection programming set points shall be coordinated with downstream
feeder breakers. Coordinate charts indicating breaker settings shall be provided by
the equipment manufacturer.
I.
Branch circuit breakers, 600 A and larger shall be bolt-on group mounted, 100%
rated, solid trip molded plastic case, air circuit breaker type. Breakers shall have
solid state trip units and a common trip bar so that the tripping of one pole will
automatically trip all the poles of the breaker. Breakers shall be trip-free and
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trip-indicating and shall have quick-make, quick-break contacts. Breakers shall
have 10,000 AIC, RSM, SYM minimum at 480 volts.
J.
Branch circuit breakers shall be plug-in group mounted, molded plastic case, less
than 600A type. Breakers shall have thermal-magnetic trip units and a common trip
bar so that the tripping of one pole will automatically trip all poles of the breaker.
Breakers shall be trip-free and trip-indicating and shall have quick-make,
quick-break contacts. Current limiting circuit breakers shall have 10,000 AIC, RMS,
SYM minimum.
K.
Metering: A voltmeter and ammeter shall be mounted in the door and supplied with
current and potential transformers and instrument transfer switches. All front plates
used for mounting meters, instrument transfer switches or other front mounted
devices shall be hinged with all wiring installed and laced with flexibility at the
hinged side. Metering unit shall have one percent accuracy. Metering unit shall
indicate current, volt, frequency, P.F. in a solid state construction with digital
readout. Square D type DM 50.
PART 3 - EXECUTION
3.01
EXAMINATION
A.
Examine areas and conditions under which switchboards and components are to be
installed, and notify the CONTRACTOR in writing of conditions detrimental to proper
completion of the work. Do not proceed with the work until unsatisfactory conditions
have been corrected in a manner acceptable to the ENGINEER and OWNER.
3.02
INSTALLATION OF SWITCHBOARDS
A.
Install switchboards as indicated, in accordance with manufacturer's written
instructions, and with recognized industry practices; complying with applicable
requirements of NEC, NEMA's Stds Pub/No. PB 2.1, and NECA's "Standard of
Installation".
B.
Tighten connectors and terminals, including screws and bolts, in accordance with
equipment manufacturer's published torque tightening values for equipment
connectors. Where manufacturer's torquing requirements are not indicated, tighten
connectors and terminals to comply with tightening torques specified in UL Stds
486A and B, and the National Electrical Code.
3.03
FIELD QUALITY CONTROL
A.
Prior to energization of circuitry, check all accessible connections to manufacturer's
tightening torque specifications.
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B.
Prior to energization of switchboards, check with ground resistance tester,
phase-to-phase and phase-to-ground insulation resistance levels to insure
requirements are fulfilled.
C.
Prior to energization, check switchboards for electrical continuity and for
short-circuits.
3.04
ADJUSTING AND CLEANING
A.
Adjust operating mechanisms for free mechanical movement.
B.
Touch-up scratched or marred enclosure surfaces to match original finishes.
3.05
GROUNDING
A.
Provide equipment grounding connections for switchboard as indicated in Section
16060. Tighten connections to comply with tightening torques specified in UL Std.
486A to assure permanent and effective grounding.
3.06
DEMONSTRATION
A.
Subsequent to wire and cable hook-ups, energize switchboards and demonstrate
functioning in accordance with requirements.
Where necessary, correct
malfunctioning units and then retest to demonstrate compliance.
END OF SECTION 16441