Australian Govlink Issue 2 2018 | Page 50

48 LIGHTING LIGHTING CONTROLS PRIMER The selection of lighting controls is a complex task. If chosen unwisely, the lighting will be ineffective and/or difficult to maintain. The aim of this article is to provide advice to inform those working in the public infrastructure realm to enable them to check that their designer is choosing a suitable lighting control system. There are four types of dimming protocols: • Phase dimming uses a simple phase chopping circuit originally developed for incandescent lighting controlled usually by a rotary switch or similar. • Zero to 10V dimming works by running a set of two control cables to each luminaire in addition to the power cables. • DALI dimming Digital Addressable Lighting Interface is a protocol that allows each luminaire to be addressed individually using a digital signal and is the most modern dimming system being developed. It requires two wires to each device in addition to the power cabling. As each luminaire can be digitally individually addressed it allows “scenes” to be created through third party controllers that are programmed to achieve the results required. • DMX provides 512 channels per “Universe” that is very useful for controlling lighting where there are large numbers of RGBW lighting sources such as on a building façade. DIMMING CONTROL SYSTEMS The choice of the dimming method is only one part of the design. The second consideration is how the lighting will be controlled. Generally there are three options: 1. Local: The lighting is controlled from a local panel, usually quite simply using rotary or similar controls. ideal for smaller projects.. 2. Centralised: The lighting is controlled from a central point by a “head end” panel of some sort, ideal for complex designs such as lighting the façade of major buildings, complex catenary lighting or tunnel lighting tasks. It allows very complex lighting designs such as colour shift and special shows to be programmed. It can be used for daylight harvesting and for remote control. 3. Distributed: Individual luminaires have intelligence and link together usually using WiFi which is ideal for street lighting and for office lighting within council buildings. The most modern development, it allows ease of extension to lighting plans and is the most flexible. In the office environment, for instance the lighting can be programmed at each desk position to suit the GOVLINK » ISSUE 2 2018 participant using a hand held device by managers. It doesn’t require a technician and doesn’t require rewiring of existing lighting positions. EXAMPLES Webb Australia are responsible for designing a large number of successful lighting installations using the various dimming technologies. Some examples include: The Ross Street path in Toorak: This installation uses combined sensor controls and dimming with solar power to provide non-grid connected path illumination with reduced energy consumption thereby reducing solar panel size and frequency. Centralised system examples include the Melbourne GPO and the Larissa underpass. Each involved complex designs and programing to produce vibrant effects. Follow the link to see the dynamic lighting of the Larissa underpass. This very successful installation stopped vandalism and made the underpass popular with local commuters and residents. https://vimeo.com/64692959 A good example of distributed lighting is the Council offices of the City of Kingston. The existing fluorescent lighting was changed to LED with distributed control. The final installation resulted in energy savings approaching 50% of previous use as well as greatly improving user comfort for Council staff. Barangaroo Headland Park: A safe, energy efficient and visually attractive public environment was created for people of all ages and mobility to enjoy the Park during the day and night, with the space being accessible 24 hours a day. The installation comprised of specially manufactured LED post top luminaires of a single type and regular spacings provided a recognised standard for development across Barangaroo. Narrow strip lights, embedded at regular intervals, located within the ‘1836’ sandstone wall and central promenade sandstone provide feature aesthetic. A distributed control system, in conjunction wit