Home' Australian Govlink : Issue 1 2016 Contents 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 project managers 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.
The advantages of this method is its simplicity and low
cost. It is generally only applicable to small areas.
Complex luminaires containing many LEDs are usually not
be available with this option. It is low cost, simple
Zero to 10V dimming works by running a set of two control
cables to each luminaire in addition to the power cables.
The 0-10V controller located within each luminaire will
detect the voltage and dim the lighting to suit.
The advantage of this method is its simplicity. Large
numbers of devices can be dimmed simultaneously.
It is relatively inexpensive and simple to operate
however a separate set of wires is required to every
luminaire if it is required to dim them independently,
creating a complex web of cabling and controls.
Many European sourced luminaires will not offer this as
a dimming method.
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.
DALI is the preferred method of dimming for large
commercial areas. If used in a very large number of devices,
especially when colour changing is required, a detectable
lag may occur producing a Mexican wave effect.
DMX provides 512 channels per “Universe” that is very
useful for controlling lighting where there are lots of
RGBW lighting sources such as on a building façade.
DMX like DALI allows daisy chain cabling and yet address
each device individually.
DMX cables are suited for creating large scenes and there
is a large section of equipment available such as lighting
desks that enable complex lighting control productions.
DMX allows special functions such as motorised
positioning and scenes triggered by events.
DIMMING CONTROL SYSTEMS
The choice of the dimming method is only one part of
the design. The second consideration is how will the
lighting 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. 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. For example, in the office environment, the
lighting can be programmed at each desk position to
suit the participant using a hand held device by
managers. It doesn’t require a technician and doesn’t
require rewiring of existing lighting positions.
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 a non grid connected path illumination with
reduced energy consumption thereby reducing solar
panel size and battery size.
Centralised system examples include the Melbourne
GPO and the Larissa underpass. Each involves 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
resulting installation has resulted in energy savings
approaching 50% of previous use as well as greatly
improving user comfort for council staff.
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