Introduction To Lighting Controls

Introduction


Lighting controls play a critical role in electric lighting systems, providing the functions of

  • turning the lights on and off using a switch;
  • Adjusting light output up and down using a dimmer.


In recent decades ,technological development  has increasingly automated these functions and allowed integration of devices into larger ,more flexible systems.The result is significantly expanding energy saving opportunities,flexibility reliability and inter operability between devices from different manufacturers.

A good Lighting design includes a good controls design.

The goal of an effective controls design is to provide for eliminating energy waste while providing a productive visual environment.

A Lighting controls system or device is an appartus that 1) receives information 2) decides what to do with the information 3) changes the operation of the lighting system.
A robust Lighting control system provides a control  station, occupancy sensor,photosensor and time switch or centralized switching system with inputs and the output is provided to the Lighting Load.

Purposes Of Lighting Controls


  • Providing the right amount of light
  • Providing that Light where it is needed
Lighting controls provide flexibility in adapting the lighting system to different uses. Lighting controls and controllable ballasts provide the ability for users to adjust light levels based on changing needs or individual preference.
By establishing control zones lighting controls allow putting of light where its needed.
A switching system can be scheduled to automatically shut off the lights by area, by floor or in a entire area if a building's occupancy is predictable.
if occupancy is not predictable  , a threshold event based strategy can be considered,for e.g the lights can be switched on or off based on the fact whether the sensor detects the presence or absence of persons in the area defined.

Lighting controls aid in Energy Management.

  • Controls reduce the amount of power drawn by the lighting system during operation
  • Controls also reduce the power drawn during peak energy demand period, when demand charges are highest. 

The Right Control Strategy

The following questions should be asked  before arriving at the right control strategy:
  • What are the Load and space characterstics?
  • What are the projects goals of the lighting systems?
  • What is required by energy,building and electrical codes?
  • Should the Load be switched or dimmed?
  • What degree of automation is required?
  • Should the lighting system be controlled locally or from a centralised location or both?
  • What degree of control accuracy is required? 
  • Who will commission the control system?
  • What is the target value level the balance between performance and cost?


Comments

Post a Comment

Popular posts from this blog

Li-Fi LEDs for Internet of Things

Image
Li-Fi   is a   bidirectional , high speed and fully networked   wireless communication   technology similar to   Wi-Fi . Coined by Prof. Harald Haas, Li-Fi is a subset of   optical wireless communications   (OWC) and can be a complement to   RF communication   ( Wi-Fi   or   Cellular network ), or a replacement in contexts of   data broadcasting . It is wireless and uses   visible light communication   or infra-red and near ultraviolet (instead of radio frequency waves) spectrum, part of optical wireless communications technology, which carries much more information, and has been proposed as a solution to the   RF-bandwidth limitations .   A complete solution includes an industry led standardization process. Technology details This OWC technology uses light from  light-emitting diodes  (LEDs) as a medium to deliver networked, mobile, high-speed communication in a similar manner to  Wi-Fi . Li-Fi could lead to the  Internet of Things , which is everything electronic being conn
Read more

Factors Influencing the Lighting Design

Image
Lighting is an Art as well  as a Science. There is no ideal or optimum solution to a particular lighting problem. The design process should be seen as consisting of two quite distinct phases. Phase one begins with the client, and involves studying the various local factors that will influence the design. Phase two is the design process proper, and it is here that the first of many design decisions are made. Factors Influencing the Design It is very important that the lighting designer establishes a very good working relationship with the client and with all the others engaged in the project ( such as architects, interior designers, air conditioning engineers) at the earliest possible stage in its development. It will then often be possible to influence basic design conditions concerning the space to be lighted. Later on it might well be too late to make those changes that would have simplified or improved the final lighting design. The most important factors dictated by the cli
Read more

Light Color and Color Rendering

Image
True Colors do not exist. People tend to judge colors under what they consider to be natural or true lighting conditions, often  mistakenly using daylight for this purpose. but the colors seen under daylight on a Sunny day can be widely different to those seen on a day with overcast sky. For the spectral distribution of daylight is not constant, but is continually changing from hour to hour and from season to season. The correct thing to do, of course , is to assess the colors under the same type of lighting as that existing in the area where they will be finally seen. For example, an evening dress would be chosen under incandescent lighting, for this is the sort of lighting most likely to be employed at the evening function where it will be worn. Similarly, the color scheme for an office should be preferably be chosen under lighting identical to that which will later be installed there. Image Courtesy Philips Spectral Distribution The spectral distribution of the light determ
Read more