Guide to Popular LED Dimming Options

Modular Lighting & Partners supply complete fixtures with LED drivers built-in or remote, you may see this on our quotes as GE – gear excluded or GI – gear integral. If dimming MLP need to know what dimming protocol the installation will be using. We do not supply the control system except Hue Connect.

In professional projects the dimming protocol has normally been selected by the electrical consultant. Understanding the different dimming types is critical to the success of any lighting project.

Our advice is DO NOT use phase-cut (main voltage) dimming. If you do, be aware of the limitations. We do not warrant phase-cut dimming performance. See below.

Phase-Cut Dimming (Trailing Edge/Leading Edge)

The most basic form of dimming originally developed for resistive incandescent loads (where it worked really well) This is your typical domestic type wall dimmer. No additional wiring, standard active, neural and earth. The dimmer simply “chops” or “cuts” the voltage phase going to the LED driver. The dimmer is connected to the active line.

  • No extra wiring is required.
  • LED Dimmers widely available from electrical wholesalers.
  • Wide selection of LED drivers available with correct mA and Vf

Many LED drivers are capable of phase-cut dimming, “capable” being the operative word! Just because they are “capable” does not mean they will work every time, every dim level and every way you expect. Expect as minimum

  • Flickering LEDs
  • Poor dimming performance – LEDs don’t dim or do not dim to the level you want
  • LEDs pop off at low levels
  • Large jumps or steps in light output when dimming
  • Lights flashing around 10pm due to hot water load switching. This is the time you home, restaurant or bar lights will be dimmed – be warned

There are millions of combinations of LED drivers, LED phase-cut dimmers and LED lamps / fixtures making compatibility an issue. Our position is “DO NOT dim LEDs with phase-cut” if you do, expect problems. Our warranty will not cover dimming performance, if the driver and fixture operates on a standard on/off switched circuit it is deemed as working correctly.

Phase Dim Wiring Diagram
Switch Dim or Push DIM

Switch Dim is Tridonic’s version of Push dim.

Is one of the simplest types of professional dimming available. Suitable for use in small to medium sized installations. No digital controllers are required, the regular switch is replaced with a mechanical push button- Each driver requires a standard wiring plus a 1 or 2 Core Switch wire, a mechanical “normally open” push button switch is required to operate a Switch dim / Push DIM system. Don’t mix different brands of drivers on the same circuit and check the wiring diagram of the driver before electrical 1stfix.

  • Excellent stable dimming 100-1%
  • One push button for on/off and dim
  • 1-2 Core switch wire required depending on the driver brand
  • Dimming occurs through the use of a “normally open” type push button switch, push for “on” push for “off” push and hold to “dim”
  • Drivers available to suit most LED mA and Vf (Tridonic, Osram, Vossloh, TCI etc.)
Push Dim Wiring Diagram
1-10V Dimming

1-10V (Analogue) Dimming uses an analogue signal. It is a universal protocol, so all 1-10V drivers operate in the same manner. Each driver requires a standard switched wiring plus two core control line to carry the low voltage signal (which is polarity sensitive) most electricians use “bell wire” for the 1-10v control wire. In its simplest form use a rotary potentiometer or 1-10V controller, Modular Hue Connect or professional dimming system. Excellent stable dimming 100-1%

  • Additional 2-Core LV control cable is required.
  • Works with Hue Connect wireless lighting control
  • 1-10V controller or potentiometer is required. Some quantity limits to each potentiometer
  • 240v load still required to be switched to off
  • 1-10v drivers available to suit most LED mA and Vf (EldoLED, Tridonic, Osram, Vossloh, TCI etc.)
1-10V Dimming Wiring Diagram

DTK-3 for Clipsal or HPM face plate, requires on/off switch for 240v


The default professional dimming protocol.

Digital Addressable Lighting Interface – DALI – is a universal protocol (IEC 62386), designed to allow varying manufacturers drivers to all work on the same system. It doesn’t matter whose light fitting or driver you are using, if it is DALI it will work on a DALI control system. Up to 64 light fittings / drivers can be controlled per DALI line, buildings can have multiple DALI lines. Wiring to a DALI fixture requires a standard active/neutral/earth, plus two DALI control lines (not polarity sensitive).

The “A” in Dali stands for “addressable” this means the driver can be “addressed” by software and told what it is and where it is. Dali drivers are always in standby, waiting for a Dali signal to turn on and go to a dim level. Very impressive, very flexible but needs complex expensive control systems and an Integrator to make it all work (an maintain)

Needs a Dali controller, this is normally a professional system e.g. Dynalite, C-Bus or similar

  • Excellent stable dimming 100-1% and some drivers to 0.1%
  • Additional 2-Core building control cable is required.
  • Fittings are connected to the Dali line and then addressed – no switched circuits.
  • Dedicated DALI interface or Control System is required to control this System
  • 1-10v drivers available to suit most LED mA and Vf (EldoLED, Tridonic, Osram, Vossloh, TCI etc.)

Dali drivers can also be wired in “broadcast” mode. This is wired with the Dali drivers in a traditional circuit, the Dali “broadcast signal is sent to each driver in the wired circuit, On/Off dim Up/Down.

DALI Dimming Wiring Diagram

A number of simple broadcast controllers are available like Diginet DALI Wall Plate Dimmerfor on/off and brightness or Tunable white. The wall plate is 240v powered with a built in Dali power supply.

Remember …

  • Don’t phase dim LEDs, if you do know this expected performance issues critical in hospitality installations.
  • Select the dimming system before running cables on site and ensure your electrician understand the system you want and allows the correct wiring.

Questions? Ask Our Experts

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