The majority of states maintain commercial building
energy codes based on either
the ANSI/ASHRAE/IES 90. 1
energy standard or the model
International Energy Conservation Code (IECC). The
2010–2013 versions of 90. 1
and the 2012–2015 versions of
the IECC require automatic
control of outdoor curfew and
dusk-to-dawn lighting as follows, with some exemptions.
A combination photocell/
time switch must control
curfew lighting. The photo-
cell turns the lighting on. The
time switch turns it off at a set time after-hours when no longer
needed. The lighting must turn off between
midnight or business closing (whichever is
later) and 6 a.m. or business opening (which-
ever is earlier), or on whatever schedule the
authority having jurisdiction allows.
A photocell must turn dusk-to-dawn
lighting on and off. In addition, a control
must reduce lighting power by at least 30
percent. This can be accomplished using
either scheduling or occupancy sensing.
If scheduling is used, the lights must be
reduced from midnight or within one hour
of end of business operations (whichever
is later) until 6 a.m. or business opening
(whichever is earlier). If occupancy sensing
is used, the lights must be reduced after no
activity is detected for about 15 minutes.
The 2016 version of 90. 1 goes even further. Dusk-to-dawn
lighting must be capable of reducing power by at least 50 percent, up from 30 percent in the previous versions. Additionally,
certain outdoor parking area lighting (greater than 78 watts
[W] and a mounting height of 24 feet or less) must be reduced
by at least 50 percent using an occupancy sensor after 15 minutes of inactivity, and each sensor must be limited to controlling
up to 1,500W of lighting power.
A sample sequence of operation follows for dusk-to-dawn
luminaires that do not require full output during all operating
hours. The photocell activates the luminaire. At a certain time
of night, a time-based controller, which may reside at the luminaire or a remote panel, reduces output across all luminaires. A
passive-infrared occupancy sensor then raises or lowers light
and power based on occupancy.
Energy codes provide a baseline of energy efficiency for
new construction and renovations but may also serve as a best
practice for energy-saving upgrades in existing construction.
Despite significant energy savings potential, new controls are
sometimes difficult to justify as a stand-alone upgrade. How-
ever, integrating controls into an LED upgrade can produce an
economically viable solution, especially when utility rebates
Incorporating intelligent control and wireless communication
presents additional capabilities. Intelligence entails use of a
microprocessor-based lighting controller for decision-making.
By putting a controller in each luminaire, the luminaire becomes
capable of operating independently. For example, its operating
schedule and degree of lighting reduction could adjust based on
the application; luminaire output could be brightest at sunrise/
sunset and automatically reduce the rest of the night.
Wireless communication eliminates wiring from controller
networking, making networking more economical. This allows
remote calibration, programming and zoning of luminaires both
individually and as groups. Another potential
capability is measuring and monitoring that
produces data usable for energy management,
maintenance and security.
For example, the system could alert operators to a fault or failure, such as a luminaire
operating during the day, while showing
exactly where the problem is occurring.
The wireless system is typically based on a
series of gateways that manage information
from nodes embedded or mounted on the
luminaires. Operators access these gateways
using software. Most networks use a mesh—or
tree—architecture, which features repeating
and self-healing nodes. A variety of protocols
and methods, such as ZigBee, are used.
Due to the many types of available systems and approaches, be sure that a selected system has all the
The ultimate expression of the potential inherent in intelligent wireless control is the “smart city.” Just as the Internet
of Things (Io T) offers exciting potential to transform living and
workspaces, LED lighting, coupled with sensing, connectivity
and software, enables similar possibilities for cities.
Smart cities include a network of systems that is programmable, automatically responds to environmental conditions and
collects data. Buildings, information technology and energy
systems may be integrated. It is an Io T strategy applied to cities.
Applicable energy systems include lighting, automation,
life/safety, telecommunications and facilities management. All
run on ethernet/IP to enable human/system/object interaction,
response and reporting.
Lighting controls save
energy by turning off or
reducing lighting when
it’s not needed. The
smarter the control and
the more flexible the
light source, the greater
precision in delivering
maximum energy savings.
Because LED lighting
is instant-on and easily
lighting control now
offers higher energy cost
savings through flexibility.
Eaton Corp.’s intelligent wireless
lighting controller provides on/off,
and optional GPS positioning.