Lighting Control

Contol the mood with lighting

Introduction
Today, when even the smallest capital expense requires approval from the top, electricity is an easy place to cut costs. New lighting control technologies help you light the workplace appropriately and save money along the way.

Lighting control has come a long way from the early days of the simple toggle switch. Now lighting designers have devices like passive infrared detectors, solid-state contactors, ultrasonic devices, and photosensitive controls at their disposal. In fact, manufacturers are developing new lighting control devices and systems at such a rapid pace; few new projects will incorporate the same components.

Control Strategies
The most prevalent modern lighting control strategies can be divided into four categories: occupancy-based, schedule-based, light-level control, and load shedding.

Light-level control switches between the following three types of control to adjust the light output in response to defined objectives:

• Delighting allows natural light that enters a building or structure to supplement electric lighting systems.
• Tuning allows the adjustment of light levels to match the different activities conducted in a space.
• The lighting system is set to a predetermined dimming level when the lamps are initially installed, and the light level is increased incrementally as the lumen output of the lamps decreases over time.

Control Mediums
Lighting system control signals can be distributed throughout a facility via a low-voltage communications bus or a power-line carrier system.

A low-voltage communications bus uses a set of twisted-pair copper conductors to carry data to and from control panels and other equipment. The bus control system simplifies wiring, which means that individual, group, or pattern switching of lighting can be easily changed or added.

Equipment Review
Lighting control devices are classified as on/off devices or power level setting control devices. Those that provide on/off-switching control include:

A wall switch can control a branch circuit directly or a contactor or relay operating coil to achieve multiple-circuit control in a single action. In a space where a number of lighting circuits are installed, it's standard practice to group a number of wall switches in a single location, such as a doorway. This will permit selective use of specific lighting loads in the space and allow different light levels to be established.

Locations with more than one means of entering or leaving an area, such as a passageway or corridor, commonly call for 3- and 4-way switches. A number of NEC rules must be observed in this case, such as the requirements on the identification of travelers.

Hence lighting control is all about light saving.

There are many more fixture articles in our fixture section. There is more specific information in the links at the beginning of this article. They can guide you where you need to go.