Electrical lighting controls are devices that help to control lighting luminaires. They include a simple control switch to sophisticated relays and panels all to enhance building efficiency. Every lighting system comprises of the load and the controller. The load is the lighting luminaire that will produce the illuminance while the controller is the device that will adjust the loads to provide output. Controllers must be compatible with the load they are controlling.
Lighting controls are required to be properly designed to save a lot of energy, improve the lighting effects, and extend the life of lamps or ballasts.
Electrical building services engineers are required to consider how they are to be deployed in a project and how they will interact with the lighting luminaires in providing a desirable lighting response.
Types of Lighting Control System
1- Individual Lighting Control System: This is a lighting control system in which the controller is directly connected to the lighting luminaires or group of luminaires in a single space.
2- Network Lighting Control System: This is a lighting control system in which a group of individual controls is linked to a centralized controller. This gives the opportunity of controlling multiple spaces from a single point without interfering with the individual controls.
3- Preset Lighting Control System: This is a lighting control system that allows setting lighting luminaires at a preferred set called Scene. The scenes are saved and reviewed by any form of controller based on a limited number of configurations.
Classification of Lighting Controls Based on Interaction
Lighting controls continue to evolve due to the increasing demand for energy savings, better lighting effects, and extending the life of lamps. They can thus be classified based on their interaction with the building lighting system into:
1- Manual Lighting Control which are wired lighting controllers used in controlling individual or groups of lights by hand.
2- Automatic Lighting Control which is a lighting controller used in controlling individuals or groups of lights automatically mostly by sensors and relays.
Classification of lighting Controls based on the response
As home occupants’ demand for comfort and flexibility keeps increasing, lighting controls can be designed to satisfy occupant needs by the use of efficient lighting controls. The common lighting controls based on their reactions to luminaires can be classified into:
1- Direct Query Lighting Controls are binary lighting controls. They are mostly used to turn the lighting circuit ON/OFF.
2- Dimming Query Lighting Controls are the 4bit lighting controls. These controls do have the ability to adjust and adapt the luminaires lighting levels gradually by either darkening or brightening the fixtures.
Some controls can operate on mains voltage, while others are low-voltage (DC) powered.
Types of Lighting Controls
All lighting controls have their advantages and disadvantages, they also help to save a lot of energy, creating better lighting effects and extending the life of lamps. We are going to look at all the types of lighting controls that are used in the building services industries:
1- Standard on/off switches
4- Timer light switches
5- Sensors (Automatic)
6- Keypads, Touch panels, voice, and mobile devices
Standard On/Off Switches
Standard on/off switches also called the manual switches are forms of a direct query lighting control system. They are cost-effective and also the most common types of the control system in the construction industry with an amperage rating of 5A to 15A.
Standard on/off switches exists in different varieties which include the Bed Switch which is a hanging type of switch used with bed lamps, the Flush Switch which is the most common type and is fixed in walls, or the deprecated tumbler switches common in old homes.
These types of lighting controls can exist as a single unit called A One Gang Switch having a single rocker on them, or as a combined two-unit generally called Two Gang Switch, and a combined three-unit called the Three Gang Switch. The Four Gang Switch is also available but is rarely used because of the ambiguity in identifying each gang designation.
Moreover, when Standard on/off switches is connected to an electrical lighting circuit, they can be connected as a Single-way pattern when they control the luminaire from a point, or as a Two-way pattern when two switches control a single lighting circuit from different points. This pattern is mostly implored in stairways, lobbies, or halls as the luminaire can comfortably control from any of the entry. They can also be connected to a circuit in a Three-way or Intermediate pattern when three switches control a single lighting circuit from a different point.
Dimmer lighting control is a form of Dimming query lighting control system. They are less common compared to the Standard ON/OFF switches but are of greater comfort as illumination from the luminance can be set to a comfortable or mood level. They also provide occupants with the flexibility to instantly change the characteristics of space to make it more comfortable and productive. This thus protects the occupant from the glaring effect even if the project is poorly designed.
Relay lighting controllers are sophisticated low current controllers that can interact and relate to lighting luminaires in different ways. They exist mostly in panels (Lighting Control Module) managing a large group of luminaires and lighting circuits by triggering a number of an event at specific times or under certain load conditions. This thus allows luminaires to be controlled either by adjusting or by direct querying method.
Relays also provide the ability to control lighting luminaires by the use of Infrared Remote control or automatically based on pre-programmed function.
They also make lighting integration easier for automation, other building systems, and green buildings system as only the relay circuit is required to be connected to the network.
Timer Light Switches
Timer light Switches are forms of automatic direct query lighting controllers with a built-in time clock. These switches control luminaires based on preset time or times at preset intervals. These types of switches use either a programmable electronic timer or mechanical strings to operate.
They are mainly useful for routine applications such as the security lighting which are only to be ON during the dawn and to be OFF within a pre-set time of the day.
Sensors are automatic lighting controllers based on presence (Presence sensors) or the environment illumination level (Photosensor).
Presence sensors as the name suggest are automatic lighting controllers based on the presence of a temperate body. They thus send an impulse to their connected lighting circuit(s) a body that comes into their target monitored area. They are also of different types especially based on the technology they use to operate.
The Passive infrared sensors (PIR) is a form of Presence sensor solemnly designed to detect heat-emitting body such as human, animal, cars, etc by measuring the changes in the infrared level emitted by the surrounding object. Ultrasonic sensors emit an inaudible sound pattern that can be disrupted by any moving object. The Dual-technology presence sensors use both the PIR and Ultrasonic technologies to avoid false triggering.
The motion sensor is also a type of presence sensor common in the industry. These sensor types respond to any moving object mostly by a set sensitivity level making them very useful for utility and security lighting.
They are also mostly installed at the wall corner or ceiling spot of the ceiling, and Engineers are required to consider their coverage patterns and width while deciding the best fit for a project.
Photosensors are also known as Light-level sensors because they depend on the presence of light in the space. The most common types are the LDR based sensor that has the ability to changes with the light intensity that falls upon them. This thus gives the ability to use them as switches or for maintaining the desired light level by providing a smooth transition of the luminaire as daylight increases or decreases called daylight dimming.
Keypads, Touch Panels, Voice and Mobile Devices
Keypads, Touch panels, and mobile devices are been implemented as lighting control in modern buildings. Building occupants that do demands flexibility and an intelligent lighting system may decide to deploy them into the home automation system.