UNIVERSITY OF ALABAMA AT BIRMINGHAM
DEPARTMENT OF FACILITIES PLANNING
FACILITIES STANDARD
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NAME: Switchboards
NUMBER: 16162
ORIGINAL DATE: 11-05-98
REVISION DATE: 05-04-01
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PURPOSE:
1.
The general purpose of each Facilities Standard is to provide minimal criteria for
construction materials at University facilities regarding code compliance, warranty,
approved products, execution and uniformity.
2.
To protect the health and safety of patients, visitors, students, faculty and staff, in
addition to protecting non-project UAB property, all construction must be in
accordance with: NFPA 241 safeguarding construction, alteration and demolition
operations; Standard Building Code, Chapter 33, regarding site work, demolition
and construction; NFPA 101 Life Safety Code.
3.
Construction safety is the responsibility of the contractor in accordance with the
regulations and codes of the agency having jurisdiction, and according to the
guidelines adapted by OSHA.
4.
The Switchboards Standard establishes a series of guidelines for specifying this
particular item on any construction project at the University. This Facilities
Standard is not to be regarded as a specification.
GENERAL:
A.
Low Voltage switchboards shall be dead front, totally enclosed in NEMA 1
enclosures, self-supporting metal structures.
The switchboards shall be
completely front-accessible. Sections shall be flush at the rear and front.
B.
Equipment shall be designed, manufactured, and tested in accordance with the
latest NEMA PB-2 Standard and UL 891. Service switchboard shall have UL
Service Entrance label.
C.
Bussing shall be tin plated copper. Bus shall have sufficient cross sectional area
to continuously conduct full load current, based on 1,000 ampere per square inch
copper. Neutral shall be 100%. Ground bus shall be provided.
D.
Engineer shall specify the short circuit rating of the switchboard. The switchboard,
as a complete unit, shall be given a full, not integrated or series,
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NAME: Switchboards
NUMBER: 16162
ORIGINAL DATE: 11-05-98
REVISION DATE: 05-04-01
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short circuit rating by the equipment manufacturer, and shall be listed on the
manufacturer’s nameplate.
E.
Main service switches, 1,000 ampere or larger shall be equipped with ground
fault sensing, and automatic trip. For each ground fault protection system
furnished, a test-monitor panel shall be provided, flush mounted on front of
switchboard. Ground fault relays shall be solid-state construction, and have
adjustable pick-up for ground fault currents from 200 to 1,200 ampere. The
Engineer shall furnish the setting of the relay as recommended by the equipment
vendor and shown on the drawings. Time delay provided by the ground fault
circuitry shall be nominally 0.3 second, and shall be permanently calibrated to
preclude tampering with the time delay after the installation.
F.
Large service switchboards, fed with 500 MCM cables and larger, shall be
provided with groundable neutral bar and disconnect link, and shall be bonded to
switchboard enclosure (and not each service switch per exception No. 3 of NEC
250-23b). The Engineer shall provide a breaker tripping coordination study.
G.
Metering for large switchboards as defined in Section F above shall be equipped
with communication capabilities over an open communication network, to a
personal computer with Real Time Operating System and Windows NT. This
communication system shall be the same as the one used for motor starters.
Refer to Standard # 15953 “Central Monitoring and Alarm”, and Standard #
16155 “Motor Starters”. 400 ampere and larger circuit breakers shall have
microprocessor based RMS sensing trip units.
H.
800 amp low voltage circuit breakers and larger shall be Drawout Power type in
Metal Enclosed Switchgears.
I.
Distribution system shall be designed so that one floor interruption or shutdown
does not necessitate the interruption of other floors.
J.
Distribution equipment supplying data processing, communication, or
electronic medical instrumentation loads shall be provided with Transient
Voltage Surge Suppression devices (TVSS) based upon ANSI/IEEE
recommendations.
PRODUCTS:
1. Switchboards approved manufacturers:
a)
General Electric
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DEVELOPED OR INTENDED FOR UAB
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══════════════════════════════════════════════════════════════════
NAME: Switchboards
NUMBER: 16162
ORIGINAL DATE: 11-05-98
REVISION DATE: 05-04-01
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b)
Square D
c)
Cutler-Hammer
2. TVSS approved manufacturers:
Same as switchboard manufacturer, or:
a)
Surge Suppression Inc.
b)
International Power Machines.
EXECUTION:
A.
In addition to the factory tests, the Contractor shall inspect and test the equipment
for damage after shipment. With switches open, PT fuses removed, CT’s short
circuited and grounded, the buses shall be given a 500 Volt DC megger test.
Minimum megger reading shall be 10 megohm.
B.
Contractor shall set the breakers tripping according to the Engineer’s furnished
study, and provide test results.
END OF STANDARD
Prepared by:
____________________________________________
_________________________________________
Samy A. George
Reviewed and
Recommended by: ___________________________________________
__________________________________________
Mark A. Goska
Director, Architecture & Engineering
Revised by:
Samy A. George
Approved:
Brooks H. Baker III
Associate Vice President - Facilities
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