A Tunable white light is a luminaire which can provide different shades of white light, from cool white light to warm white light. This can be used together with a Scene Controller for aesthetic effect, or it can be used with a time-based controller to gradually change the colour temperature throughout the day for physiological benefits i.e. Circadian Rhythms.
Hardware in Luminaires
Wireless Radio Controllers switch lights on and off and set their output level using a DALI interface between the Wireless Radio Controller and the luminaire’s driver. The same DALI interface can also set the colour temperature of the light, provided that the driver can accept colour commands and the luminaire has a set of Warm and a set of Cool LEDs. A DALI driver that accepts Colour these special colour commands is known as a DALI Device Type 8 (DT8) driver. The driver will have two outputs for Warm and Cool LEDs:
The usual way of changing LED boards to have both warm and cool colours, it to replace each White LED with two adjacent LEDs, one being Warm white (2,700 Kelvin) and one being Cool white (6,500 Kelvin). Doubling the number of LEDs on the board is unlikely to cause a thermal problem as the same total maximum power will be split between the Warm and Cool LEDs, thus creating the same amount of heat, but if anything dissipated more widely.
Firmware
Most Wireless Radio Devices can send DT8 Messages. Some need special firmware:
230v G2 Node (with Special Software – v3.177 at time of writing)
All Low Voltage Nodes (standard software)
All D4i Nodes (standard software)
All Batten Mounts (standard software)
E3M (Emergency Monitor) does not have a DALI output and some cannot control DT8.
Means of Control
Having created tunable white devices with DT8 drivers as above, a means of controlling the colour is required. Two methods are currently offered.
Scene Control
Wireless Radio supplies a number of devices to set and recall scenes, and to manually dim scenes. These include mains and battery powered wall-plates and key fobs. A Scene is a set of light levels for different types of luminaire. In addition to the light output, the colour can be set for each Scene, for each type of luminaire
Circadian Rhythm
Wireless Radio ACCESS POINTs can be set to broadcast a series of colour messages, so that ALL DT8 luminaires in the building imperceptibly change to mimic the sun’s colour temperatures throughout the day. The well-being benefits of Circadian Rhythms has been widely studied and published and so is not discussed in this document.
Commissioning
Stage 1. Enable DT8
Luminaires with DT8 capabilities as described above should be allocated a Profile in which DT8 is flagged as being available and enabled. In the profile screen using Component View:
Ensure that the Basic/Advanced button shows Advanced by clicking on it if necessary
Click on the Driver icon
Scroll the options area on the left hand side to the bottom if necessary
Tick DT8 Available and DT8 Enabled
Stage 2. Modify Scenes
Having enabled DT8 in the luminaires’ profile, an additional box will appear against each DT8 Profile for each Scene, when editing Scenes as below. The colour temperature is entered in Kelvin values. These range from 2,700 kelvin (very warm white light) to 6,500 kelvin (very cool white light).
Stage 3. Enable Circadian Rhythm in ACCESS POINTs
ACCESS POINTs have three pre-programmed Circadian Rhythms:
Timed Event Profile 2
Demo / test mode where colour cycles every 10 minutes
Timed Event Profile 3
3000 kelvin overnight
Fading from 3000 to 4000 between 8.00 am and midday
Increasing to 4500 kelvin between 1.00 pm and 2.00 pm
Fading back to 3000 kelvin between 4.00 pm and 6.00 pm
Timed Event Profile 4 As above, but the same cycle is also repeated between 8.00 pm and 6.00 am for night shift workers.
The Event Profile is set in the ACCESS POINT using the online Dashboard ACCESS POINT screen below. At the time of writing, the user will need super-admin privileges to see this option. Without these privileges, please contact Glamox LMS Support and ask for the Profile to be enabled in the ACCESS POINT.
Additional profiles with different colour values and timings can be created by Glamox Staff. Please contact LMS Support and provide a written schedule of times of day and required colour-temperatures.
Interaction of Scene Controllers with ACCESS POINTs and Timed Events
Colour Control messages sent from ACCESS POINTs (Circadian Rhythms) only affect colour. They will not alter the brightness of the lights nor switch them on or off.
The devices will accept the last command received. If a Scene Controller (e.g. a Key Fob) is used to recall a scene with specific colour temperatures then the scene will be recalled, but the next message from the ACCESS POINT will override the colour temperature, bringing it back in line with the selected Circadian Rhythm.
Add Comment