Using LEDs in homes, especially smart homes, is now common-place as they use as little as 10% of the energy of a conventional incandescent or halogen bulb. But they do behave differently to conventional bulbs and in many cases you need to take consideration when using them with Fibaro Dimmer 2 modules.
This application note shows how to use a Fibaro Dimmer 2 module with LED lighting in a Home Automation installation.
LED bulbs are very different to the conventional bulbs they're replacing. Conventional bulbs are based on a simple 'filament' wire that glows white hot as the electrical current passes through it. If you vary the voltage and current applied to the bulb you can directly change its brightness.
LED bulbs are more complex, they include electronic circuitry to control them and enable them to work in domestic mains (230V) electrical systems. It's this complexity that allows them to achieve such great power saving efficiency but also what makes them more difficult to use with dimmers of any type.
Many dimmers cannot be used to control LEDs (even if the LEDs are dimmable), so you need to choose a 'Universal Dimmer' such as the Fibaro Dimmer 2 module that is designed to work with a variety of lighting sources including LEDs. It intelligently analyses the bulbs connected to it and then selects the most suitable dimming type - trailing-edge or leading-edge. Trailing-edge dimmers are the best to use with electronic loads like LEDs that cause so many issues with conventional dimmers.
Using Fibaro Dimmer 2 with LEDs
Even though the Fibaro Dimmer 2 is designed to work with LEDs, there are three important points to observe; the dimmer's minimum load, its maximum load and its configuration to work with LEDs.
The Fibaro Dimmer has a minimum load of 50W. This means that, in most cases, the lighting circuit connected to the dimmer must be more than 50W. This is easy to calculate by adding-up the power (W) of all the bulbs you have on the circuit, if it's more than 50W you should have no problem. If it's less than 50W then we recommend installing a Fibaro Dimmer Bypass 2.
Note: You must use the new Dimmer Bypass 2, do not use the older Fibaro Bypass as this may damage the module or your LEDs.
Figure 1: Installing the Fibaro Dimmer 2 and Bypass 2
The Fibaro Dimmer Bypass 2 acts as an intelligent load in the lighting circuit and will help prevent the LEDs flickering at startup, low dim settings or when they should be Off. The dimmer bypass should be installed in one of the light fittings or in the wiring going to the light fitting (Figure 1), it must be connected between the light's Live and Neutral wires. You only need one Dimmer Bypass 2 for each circuit (not for each light bulb).
The way in which LEDs work can result in very high in-rush currents when they are controlled by a leading-edge dimmer (such as the Fibaro). It is common practise to de-rate the maximum power rating of the dimmer when using LEDs.
The Fibaro Dimmer 2 maximum LED load rating of 200W.
Fibaro Configuration Settings
The Fibaro Dimmer 2 has an auto-calibration that detects the type of bulb being used and sets to the dimmer to behave correctly (leading or trailing-edge). In most cases you should not need to make any further changes to the dimmer's settings.
By default a calibration will be performed after the first power on. For that reason it is not advisable to power on the Dimmer 2 without the desired Load.
During this period Z-Wave connection is disabled and the Dimmer will not reply to any commands.
The calibration result will be confirmed with the LED indicator glowing in one of the following colours:
- Green - Light source recognized as dimmable, dimming levels set, brightness may be controlled using the S1 switch.
- Yellow - Light source recognized as non-dimmable, possibility to turn On/Off connected light with default parameters settings.
- Red - Calibration procedure failed. Possible reasons: lack of connected load or connected light source exceeds maximum power, which may be controlled by the Dimmer.
- Blinking Red - Calibration procedure failed. Possible reasons: installation failure or damaged load (causing activation of the overcurrent protection)
Calibration with Bypass
By default the calibration is performed without the Fibaro Bypass. If you have a Bypass installed it is required to force the appropriate calibration procedure using the B-button menu or Parameter 13.
- Hold the B-Button until the LED glows Red
- Release the B-button and click once to confirm
- On your controller set Parameter 13 = 2 to force the calibration with the Fibaro Bypass
- When the calibration process is finished set Parameter 13 back to 0
If you need to change the load: turn off the Dimmer, change the load and launch the calibration using one of the above methods.
The lighting should not be used before changing the operating mode or calibration procedure.
Copyright Vesternet 2016