Page 205 - Alternative Energy Systems in Building Design

COMPUTERIZED LIGHTING CONTROL 181

“a” leg
“b” leg “a” leg
“b” leg “a” leg
“b” leg “a” leg
“b” leg
Breaker
panel Relay panel

Building

“a” lighting
“b” lighting

Breaker Relay panel Site lighting
panel
Figure 5.2 A typical centralized lighting-control wiring plan. Photo courtesy of LCD.

by hardwiring of various switches, dimmers, occupancy sensors, and timers. However,
in large environments, such as high-rise buildings and large commercial and industrial
environments, lighting control is accomplished by a computerized automation system
that consists of a centralized control and display system that allows for total integra-
tion of all the preceding components (Fig. 5.2).
A central lighting-control system embeds specific software algorithms that allow for
automated light-control operations to be tailored to meet specific energy and automa-
tion management requirements unique to a special environment. An automated lighting-
control system, in addition to reducing energy waste to an absolute minimum, allows
for total operator override and control from a central location.
Because of the inherent design of a centralized lighting system, the central monitoring
system offers indispensable advantages that cannot be accomplished by hardwired
systems. Some of the advantages of a centralized lighting-control system are as follows:

■ The unit allows remote manual or automatic on-off control of up to 2400 lighting
groups within a predetermined zone.
■ The unit allows remote dimming of lighting within each zone.
■ The unit allows automatic sequencing control of individual groups of lights.
■ The unit allows sequencing and graded dimming or step activation of any group of
lights.
■ The unit allows remote status monitoring of all lights within the overall complex.
■ The system controls inrush current for incandescent lights, which substantially
prolongs the life expectancy of lamps.
■ The system provides visual display of the entire system illumination throughout the
complex by means of graphic interfaces.