Brown University Revised April 12, 2013 Facilities Design & Construction Standards
Brown University Revised April 12, 2013 Facilities Design & Construction Standards
Brown University Revised April 12, 2013 Facilities Design & Construction Standards
PART 1 - GENERAL
1.1 SUMMARY:
A. This section details the general design requirements for Electrical systems, for
both new and retrofit applications.
1.2 BACKGROUND:
A. Brown University maintains it own campus electrical distribution system
which serves the majority of the buildings and facilities on the main campus.
Electricity is distributed on the campus at two operating voltages: 11.2 KV
and 4.16 KV. Both distribution systems are configured as three phase, three
wire, grounded wye. National Grid feeders supply the University electrical
distribution system at 11.2 kilovolts (kV). Electricity is in turn distributed to
facilities throughout the campus via local distribution substations and
underground electrical ductbanks and circuits. Building distribution
transformers in turn step the distribution voltage down to a utilization voltage
of 120/208 volts, three phase 4 wire and/or 480/277 volts three phase four
wire.
B. Brown University facilities located in the downtown area (Jewelry District)
are typically directly served by National Grid, the local utility company.
Buildings in this area are typically fed from the downtown network, which
is an underground network distribution system operating at 11.2 KV.
Buildings are served either from outdoor padmount style transformers or
indoor electrical vaults which directly feed the building secondary services at
a utilization voltage of 120/208 volts, three phase 4 wire and/or 480/277 volts
three phase four wire.
location on the campus. In general, new building loads of 150 KVA and
below shall be served from the 4.16 KV distribution system where it is readily
available. Loads larger 150 KVA shall be served from the 11.2 KV
distribution system.
F. In general, building loads on the 4.16 KV distribution systems are configured
as a radial primary connection; building loads on the 11.2 KV distribution
system are configured as a loop-primary connection system. Actual
distribution system connection locations and service voltages shall be
coordinated with the Brown University Facilities Operations and Engineering
staff.
G. Arc-flash labeling shall be provided for each piece of major electrical
utilization equipment being installed in the project that is likely to require
examination, adjustment, maintenance or service while energized, including
but not limited to, high voltage equipment, transformers, switchboards,
panelboards, and safety switches. Arc-flash labeling shall also be provided for
all motor starters, variable speed drives, and any other three-phase
electrically-powered mechanical equipment likely to require adjustment and
calibration while energized, such as chillers, cooling towers, boilers and
equipment control panels.
H. Electrical components, devices, and accessories: shall be Listed and labeled as
defined in NFPA 70, Article 100, by a testing agency acceptable to authorities
having jurisdiction, and marked for intended use. Where built-up electrical
systems, such as equipment control panels, are installed, they shall be listed as
an assembly.
1.8 GENERAL ELECTRICAL DESIGN REQUIREMENTS:
A. All system designs shall include detailed building One-line system diagrams
showing all major distribution system components, meters, controls and
interfaces with other building and campus utility systems.
B. For renovation projects, existing building One-line system diagrams shall be
provided with updates to clearly indicate locations of all new system tie-ins
being added, or components to be removed.
C. Buildings less than 25,000 gross sq. ft. and connected loads less than 250 kW
may have a main secondary voltage of 208Y/120V.
D. Buildings with areas exceeding 25,000 gross sq. ft., or connected loads
exceeding 150 kW are recommended to have a main secondary voltage of
480Y/277V, and 120/208V for User and small power loads.
1. Mechanical equipment and lighting panels should be 480Y/277V.
2. Distribution step down transformers should provide 208Y/120V to panels
serving convenience power and receptacle loads.
1.9 RELIABILITY AND REDUNDANCY CONSIDERATIONS FOR FACILITIES:
A. For certain Critical facilities, redundancy of electrical supplies shall be
provided where program needs require electrical power to be available in the
END OF SECTION