6.10 Branch Wiring
Lighting fixtures at all entrances and exits shall be
connected to the emergency lighting system. Where
Distribution Systems
security lighting is required and HID restrike time is not
acceptable, UPS backup, HID capacitive/ridethrough
circuitry or instant-on lamp sources may be required.
Lighting Circuit Loading
Parking and Roadway Lighting. Parking lots and roadway
120 volt circuits shall be limited to a maximum
lighting shall be designed with high-efficiency, pole-
of 1400 volt-amperes.
mounted luminaries with a maximum cutoff of 80.
277 volt circuits shall be limited to a maximum
Illumination ratios shall not exceed a 10 to 1 maximum
of 3200 volt-amperes.
to minimum ratio and a 4 to 1 average to minimum ratio.
Receptacles Circuit Loading
Structured Parking. Fixtures for parking areas must be
either fluorescent or HID. Care must be taken in locating
120 volt circuits for convenience receptacles shall be
fixtures to conform to the traffic patterns and maintain
limited to a maximum of 1440 volt-amperes (8 receptacles
the required vehicle clearance.
@ 180 watts).
Each special purpose receptacle shall be circuited
Exterior Lighting Controls
on a dedicated circuit to a protective device to match
the rating of the receptacle.
Exterior lighting circuits shall be controlled by photocell
In GSA buildings, general wiring devices shall be
and a time clock controller, with an astronomical dial, to
specification grade. Emergency receptacles shall be red.
include both all-night and part-night lighting circuits.
Isolated grounding receptacles shall be orange. Special
|A minimum of 75% of the architectural, site, and parking
purpose receptacles shall be brown. The color of standard
lighting shall be switched off three hours after the
receptacles and switches shall be coordinated with the
building is typically unoccupied or 11:00 pm, whichever
architectural color scheme; for example, white, not ivory,
is later.
devices shall be used if walls are white or light gray.
Building standard receptacle shall be duplex, specification
grade NEMA 5-20R. Special purpose receptacles shall be
provided as required. Device plates shall be plastic,
colored to match the receptacles.
Placement of Receptacles
Corridors. Receptacles in corridors shall be located 15 m
(50 feet) on center and 7.5 m (25 feet) from corridor ends.
in exterior walls and walls around permanent cores or
197
ELECTRICAL
ENGINEERING
6.10
Branch Wiring Distribution Systems
Revised March 2005 PBS-P100
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