Technical Application Knowledge: From practice, for practice
Sometimes everything in a DALI installation appears to be working correctly, but the luminaires still do not dim as expected.
The DALI bus is connected, the MCU responds, but when you try to dim the luminaires, the light output stops too early – or it seems as if the luminaires cannot dim any further.
One possible reason is the Minimum Brightness Level (Min. Level) stored directly in the DALI MCU TW G2. The control unit can save a minimum brightness value internally, which determines how far the lighting can be dimmed.
What can be adjusted
The DALI MCU TW G2 allows several parameters to be adapted directly to the connected lighting installation. It can:
- store warm and cold color temperature limits
- adapt the usable CCT range to the connected luminaires
- reset the color temperature limits and minimum brightness to the factory settings
This is useful when the available dimming or color temperature range needs to be matched to the connected luminaires.
To store the desired warm or cold color temperature limit:
- set the light to the desired warm or cold position
- press and hold the rotary knob for more than 10 seconds
To restore the color temperature limits and minimum brightness to the factory settings, switch the light off and press the rotary knob for more than 10 seconds.
Useful flexibility for retail and residential applications
In retail and residential installations, brightness and color temperature often need to be adjusted to different situations. In retail spaces, this can help adapt the lighting atmosphere in different areas. In residential applications, it provides straightforward local control of brightness and tunable white lighting.
The main advantage is that these adjustments remain simple for the user while the system itself can still be expanded when more luminaires or additional control points are required.
Can one DALI bus control up to 100 luminaires?
Yes – provided that the system is configured correctly.
The DALI MCU TW G2 supports the parallel connection of up to four control units on one DALI line.
Each active MCU, meaning an MCU connected to mains voltage, supplies the DALI bus and can control:
- up to 25 DALI luminaires or ECGs
- one passive MCU at the same time
This makes it possible to expand the system as follows:
| Number of DALI MCU TW G2 (active operation) | 1 | 2 | 3 | 4 |
| Max. number of DALI MCU TW G2 (passive operation) | 1 | 2 | 1 | – |
| Max. number of DALI EVG | 25 | 50 | 75 | 100 |
With four active control units, the installation can therefore be expanded to up to 100 DALI luminaires.
More control points without additional mains supply
A passive MCU operates without a mains supply and is used purely as an additional control point.
All connected MCUs are automatically synchronized. If brightness or color temperature is changed at one rotary control, the change is immediately reflected across the complete system without jumps in brightness or color temperature.
This can be useful wherever the same lighting installation needs to be operated from more than one position.
Designed to fit the interior
The DALI MCU G2 fits a wide range of installation frames and cover systems from different manufacturers. This makes it easier to integrate the control unit into the selected interior design, which can be particularly relevant in residential and design-oriented retail applications.
Important wiring note
When several DALI MCU TW G2 units are connected in parallel, the polarity of the DA+ and DA- connections must be observed correctly for the MCUs.
This is an important point to check during installation and commissioning, especially when several control units are used on the same DALI line.
Simple control with flexible system design
The DALI MCU TW G2 combines straightforward local control with flexible system configuration.
From setting the minimum brightness and color temperature limits to adding synchronized control points and expanding the installation to up to 100 DALI luminaires, it provides a practical way to adapt the system to different project requirements.
For retail and residential applications, this means simple user control, flexible installation and the ability to grow the system when needed.
