By James Batten, 299 Lighting · Published · Updated
In short
LED fittings dim in four main ways: phase dimming with a mains wall dimmer, DALI digital control, 1-10V analogue control and push dimming from a retractive switch; the product page tells you which one a fitting uses.
Flicker, buzzing and lights that will not dim low enough are almost always caused by a mismatch between the fitting, the driver and the dimmer. Knowing the method avoids it.
The four methods
| Method | How it works | Needs | Best for |
|---|---|---|---|
| Phase (leading or trailing edge) | Dimmer cuts the mains waveform | LED-rated wall dimmer | Homes, simple retrofits |
| DALI | Digital signal on two control wires | DALI driver and controller | Commercial, larger homes, scenes |
| 1-10V | Analogue control voltage | 1-10V driver and controller | Commercial and older systems |
| Push dim | Retractive switch on the mains | Push-dim driver | Simple dimming without a dimmer |
Phase dimming tips
Use a trailing-edge LED dimmer, and check its minimum load. A few low-wattage LEDs on a big dimmer may flicker or not dim smoothly.
DALI
DALI lets each fitting be addressed individually, grouped and set to scenes, and it reports faults. It needs a separate pair of control cables, so plan it before wiring.
The driver decides
For fittings with a separate driver, the driver sets the dimming method. Compatible drivers are listed on each product page under What you need with this fitting. See downlights and track lighting.
Frequently asked questions
Why do my LED lights flicker when dimmed?
Usually the dimmer is not LED-compatible or the load is below its minimum. Use a trailing-edge LED dimmer rated for the load.
Can DALI fittings work on a normal dimmer?
Not as DALI. They need a DALI controller or a DALI-compatible dimmer.
