DIVISION 16 - ELECTRICAL
Section 16472 - Branch Circuit Panelboards
Branch Circuit Panelboards 16472 -
Version 1– May 3, 2011
1. GENERAL
1.01 WORK INCLUDES
A. Base bid:
1. Electrical Contractor provides:
a. Branch panelboards and cabinets furnished and installed as shown or implied on the
Contract Documents.
1.02 RELATED WORK
A. Specified elsewhere:
1. 16190 - Supporting Devices.
2. 16195 - Electrical Identification.
3. 16450 - Grounding.
1.03 QUALITY ASSURANCE
A. Reference Standards:
1. Square “D” NQOD.
2. Square “D” I Line
B. Acceptable Manufacturers:
1. Square “D”
2. Siemens.
3. General Electric.
4. Cutler-Hammer.
5. Or approved equivalent.
C. Construction Standards:
1. Panelboards and cabinets shall be UL listed and labeled and constructed in accordance withNEMA standards.
1.04 REFERENCES
A. NECA (National Electrical Contractors Association) “Standard of Installation.”
B. NEMA AB 1 - Molded Case Circuit Breakers.
C. NEMA ICS 2 -Industrial Control Devices, Controllers, and Assemblies.
D. NEMA KS 1 - Enclosed Switches.
E. NEMA PB 1 - Panelboards.
F. NEMA PB 1.1 - Instructions for Safe Installation, Operation and Maintenance of Panelboards
Rated 600 Volts or less.
G. NFPA 70 - National Electrical Code.
1.05 SUBMITTALS
A. Product:
1. Submit descriptive literature in accordance with Section 01300.
2. Shop drawings shall include the following data:
a. Dimensional data.
b. Overcurrent protective devices schedule.
c. Bus ratings and bracing.
d. Installation details.
e. Manufacturer’s current specifications.
B. Maintenance Manuals:
1. Submit maintenance and operating manuals in accordance with Division 1.
2. PRODUCTS
2.01 CABINETS
A. Construction:
1. Cabinets shall be surface or flush mounted as indicated by Contract Documents; code gaugegalvanized sheet steel for flush units; surface units shall be finished in ANSI #61 gray bakedenamel. Provide a cabinet for each panelboard as indicated by Contract Documents; entireunit dead front construction; barriers as required.
2. Cabinet sizes shall be 20” wide, 6” deep.
3. Doors and trim shall be code gauge sheet steel finished in ANSI #61 baked enamel; doorsshall have directory holder and directory card; flush lock and latch for doors 48” and under,lockable handle with 3 point latch for doors larger than 48” all locks keyed alike; furnish 2keys per lock, trim for flush mounted cabinets shall overlap box by at least 3/4” all around;trim for surface mounted cabinets shall be the same size as the box.
4. Door locks shall be of lock number per directions of Owner.
2.02 PANELBOARDS
A. Bus:
1. Bus bars shall be 98% conductivity copper bars mounted on heavy insulator supports and notdependent upon circuit protective devices for support; mains shall be sized as indicated byContract Documents with minimum size being equal to the feeder size. Branches shall besame capacity as respective breaker; all joints bolted.
2. Mains shall terminate with lugs or circuit breakers as indicated by Contract Documents.
3. Copper neutral bars shall be provided; twice the capacity of mains for non-linear loads.
4. Provide a copper isolated ground bar in each panelboard.
B. Overcurrent Protective Devices:
1. Panelboard shall be complete with overcurrent protective devices and copper bus; rated forcharacteristics of service as indicated by Contract Documents; incorporating sequencephasing; mounted on reinforced back pan; and conform to Federal Specification WP-115a.
2. Interiors shall be completely factory assembled, suitable for copper wire of the size indicated;branch circuits arranged using double row construction.
3. Overcurrent protective devices shall be circuit breakers as specified.
4. Spaces shall be complete with all studs, bus and hardware for future circuit breakers withoutadditional parts or changes in bus.
5. Spares shall be complete with circuit breaker, ready to accept load side wires.
6. Panelboards shall be tested and labeled with integral short circuit rating per UL and NEMAstandards.
C. Panelboard sizes
1. Basic panelboard sizes shall be as follows:
a. 100 A, bolt-on, 120/208 V, 3 phase, 4 wire - (double size neutral), ground bus, isolatedground bus with maximum of 30 branch one pole circuit breakers and main breaker ormain lug as to be noted on drawings.
b. 225 A, bolt-on, 120/208 V, 3 phase, 4 wire - (double size neutral), ground bus, isolatedground bus with maximum of 42 branch one pole circuit breakers and main breaker ormain lug as to be noted on drawings.
c. 400 A, bolt-on, 120/208 V or 277/480V, 3 phase, 4 wire - (double size neutral), groundbus, isolated ground bus with maximum of 42 branch one pole circuit breakers and mainbreaker as to be noted on drawings.
d. 600 A., bolt-on, 120/208 V or 277/480V, 3 phase, 4 wire - (double size neutral), groundbus, isolated ground bus with maximum of 42 branch one pole circuit breakers and mainbreaker as to be noted on drawings.
3. EXECUTION
3.01 INSTALLATION
A. Mounting:
1. Panelboards shall be securely mounted in or on wall and shall be level and true. Mountingheight shall be plus 72” to top above finish floor or grade unless otherwise indicated byContract Documents.
2. Provide circuit breakers in new panelboards as indicated by Contract Documents.
3. Panelboards will not be located in classrooms. If the only alternative is to install in a
classroom, the enclosure and conduit will be enclosed in drywall walls. Panel cover will be flush on the wall.
B. Labeling:
1. Contractor shall completely and accurately type directory cards in panelboards.
2. Provide engraved micarta nameplate on front of panelboard with panelboard designation,and feeder source. See Section 16195 for type and color of nameplate.
C. Directory:
1. Provide typed circuit directory for each branch circuit panelboard.
2. Revise directory to reflect circuit changes in existing panels being worked in.
3. Copies of panel schedule are to be furnished as part of closeout documents.
END Section 16472