1 January 2005
with change 25 October 2006
3-10.1.6 The designer should prepare lighting calculations, electrical load calculations,
electrical short circuit and protective device coordination analysis and calculations. The
short circuit and protective device coordination analysis should be done using industry
standard computer software and the reports should be furnished for Government review.
Exterior Electrical Systems
3-10.2.1 The main electric power service will be obtained from the local power
company or the Government installation.
3-10.2.2 A/E should confirm in writing the service requirements from the utility or
installation to provide primary underground electrical service and pad-mounted
transformer. Pad-mounted transformer should be located a minimum of 10 feet
(3 meters) from building noncombustible wall and as required by the power company or
3-10.2.3 The empty conduits from the service transformers to the primary power
source, for service cables, and transformer pad will typically be provided by the
contractor in accordance with utility company standards. Provide transition cabinet on
transformer pad in accordance with utility company standards. Secondary underground
electrical service, including trenching and backfilling, should be provided by the
contractor. Provide current transformer (CT) cabinet for utility-furnished CTs. Utility
company normally provides meter. A 1 inch (21 mm) conduit should be routed from the
CT cabinet to the meter.
3-10.2.4 A total electrical service including all cable, pad, transformer, meter and
underground conduit, etc. will be provided for under the project design for facilities on
government installations. Coordinate with government facility DPW.
3-10.2.5 Secondary underground electrical service should be direct burial conduits,
with a spare conduit from the transformer to the main switchboard.
3-10.2.6 Exterior sign should be lighted. Flagpole should be lighted if it is determined
that flag will not be removed at night.
3-10.2.7 Exterior lighting fixtures (wallpacks, canopy lights) should be provided at
building entrances/exit doors with programmable lighting control system and a photocell.
Control should be photo on/photo off. Locate the lighting controller and time clocks in
the main electrical room. Time clock generally programmed to allow lighting between
the hours of 5:30 P.M. - 11:59 P.M..
3-10.2.8 DEPMED and MEP area should be provided with light fixtures mounted on
9.1 meter steel pole for area lighting. Consider the use of metal halide lamp light fixtures
with motion sensors and time clock for exterior lighting to turn on light fixtures when a
motion is detected in the area. The motion sensor operation shall be independent of the
time clock. Locate the lighting controller and time clocks in the main electrical room.
Maintain an average lighting level of \ 0.2 foot-candles /2/ throughout the area.