Wiring LOXONE Light

Video tutorial · 7:55 min

Wiring LOXONE Light

Prefer to read? You’ll find everything from the video below as a written guide with images and a summary. Go to the guide ↓

Written guide

If you’ve wired a LOXONE project before, you already know more than you think. Most lighting problems on site don’t come from the lights themselves, but from breaking one of a handful of wiring rules. This guide covers what lighting needs in the cabinet, how to connect each type of LOXONE light, the most common issues, and how to wire third-party lights.

Good to know: The basics aren’t repeated here in detail. For a refresher, see Wiring Essentials and Distribution Board Essentials.

01What you already know

The good news first: the rules you already know stay exactly the same. LOXONE lights use the same green Tree Cable as every other Tree device. Green/white is for data, orange/white for power, always wired color to color.

For lighting, you use the thick orange/white pair, because lights draw more power than buttons or sensors. Any topology works as long as you never close a loop. And one Tree Cable per room is still your rule of thumb.

Tree Cable rules for lighting: same green cable, color to color, thick orange/white pair for lights, never close a loop, one Tree Cable per room
Same Tree Cable, same rules: the thick orange/white pair powers the lights

02What’s different: less of everything

Every LOXONE Tree light is controlled by the Miniserver. That means no row of dimmers in the cabinet, no driver in the ceiling and no mains cable to every light. The cable follows the building, instead of the building making room for the cable.

Mains voltage lighting with dimmers and a mains cable to every light compared to LOXONE Tree lighting with one Tree Cable
Mains voltage lighting vs. LOXONE Tree lighting: the dimmer is built into every light

And there’s one more thing that takes the pressure off: lighting groups live in the software. If you decide later that the wardrobe lights need to be controlled separately, you change the group in Config. No rewiring. On site, you only need to get the position right.

Bedroom lighting groups changed in LOXONE Config without rewiring
Bed area and wardrobe as separate groups in Config, no rewiring

03How each light is connected

From a wiring point of view, every LOXONE light is either a Tree light or an Air light:

  • Tree lights get power and data over the Tree Cable. Dimming and color are controlled by the Miniserver. Just the Tree Cable, nothing else.
  • Air lights are the convenient alternative when a Tree Cable isn’t an option. They talk to the Miniserver wirelessly, but they still need power, so plan either a mains or a 24 V cable connection at the fixture. With Air, you can easily retrofit lights without changing the wiring.
  • The RGBW 24V Dimmer drives LED strips and third-party 24 V dimmable lights. It comes in Tree or Air, either for DIN rail mounting or in a compact form factor that sits closer to the light.
LOXONE Tree lights, Air lights and the RGBW 24V Dimmer in DIN rail and compact versions
Tree lights need only the Tree Cable, Air lights need a power cable, plus the RGBW 24V Dimmer

Before anyone pulls a cable: Mark on your plan which lights are Tree and which are Air.

04Power: separate supply, common ground

One of the most common issues with wiring lights is power. Supply the lights from their own 24 V output, separate from the one that runs the Miniserver and the Extensions. Lights often draw more power, and keeping them separate means a heavy lighting load can never disturb the stable supply your system needs.

There’s one critically important rule that makes this work: everything must share a common ground. Without it, the installation won’t work correctly. And don’t forget the PELV connection in the distribution board. It keeps the Tree communication to your lights stable and protects their electronics from surges.

Power Supply & Backup with separate 24 V outputs for system and lights, common ground and PELV connection
Separate outputs for system and lights, one common ground, PELV connection

05Voltage drop and LED strips

Keep voltage drop in mind whenever you plan and wire lighting. LED strips are a classic example: the power has to travel along the thin copper of the strip itself, so the further it goes, the more voltage it loses. The far end looks dimmer, and the start of the strip runs hot.

The fix is simple: one feed point for every 5 m strip. For a 10 m run, use two 5 m strips, bring the power cable to the middle and connect both strips there. The brightest ends meet in the middle, so there’s no visible step at the joint and both strips stay evenly bright.

Two 5 m LED strips fed in the middle for even brightness
Two 5 m strips fed in the middle: even brightness, no visible step

For the most consistent result, use a single RGBW Dimmer with a single suitable power supply, and connect it to each end of the 5 m strips. Place the dimmer as close to the LED strip as possible to avoid voltage drop and get the best lighting and dimming quality.

One RGBW Dimmer close to the LED strips, connected to each end of the 5 m strips
One RGBW Dimmer, as close to the strip as possible

06Third-party lights

What if your customer wants a light that isn’t from LOXONE?

  • Third-party 24 V fixtures and strips can be driven by the RGBW 24V Dimmer, just like LOXONE strips.
  • Third-party mains voltage lights are possible too, but plan for more: protection for every circuit and more wiring.
  • Dimming comes with a risk: even a light sold as dimmable may not dim properly with every dimmer, and the dimmer has to be set up correctly for that light.
  • Non-dimmable lights, both 24 V and mains voltage, can be switched on and off with LOXONE relays, which also come in Air versions.

For other cases, such as DALI fixtures in commercial projects, there are more options, covered in the LOXONE Lighting focus training. But staying within the LOXONE range is always the simplest way: fewer parts, less wiring, and one place to call if you have a question.

07Putting it all together

Here’s how it looks on a real floor plan. The cabinet sits in the landing. It contains the Miniserver and Extensions, as well as a Power Supply & Backup that powers the whole system through separate, mains-isolated outputs, each with its own fuse. Connect a backup battery, and the essential lights keep working even during a power outage, dimmed so the battery lasts longer.

  • Every room gets a Tree Cable. Spots go into the living room, kitchen, landing and both bedrooms, laid out on the grid from the Planning Guidelines.
  • Bathroom and bedroom: three Down Lights in the bathroom, two Pendulums beside the bed.
  • Living room: enough lights for two Tree Cables, which helps avoid voltage drop. Above the dining table, a Ceiling Light hangs on its Suspension Kit.
  • Kitchen: the LED strip under the cabinets connects to a compact RGBW Dimmer.
  • Sensors: place the presence sensor where it can see the doorway. It has to see someone come in before it can hear them stay. A motion sensor under each bed handles the night light, and in the hallway, where people only pass through, the sensor works with motion only.
  • And everything is wired to one common ground.
Example floor plan with LOXONE lights, Tree Cables, sensors and a common ground
The complete floor plan: Tree Cables per room, lights, sensors and a common ground

SummaryKey concepts for wiring LOXONE light

  • 1  Plan on one Tree Cable per room
  • 2  Keep voltage drop in mind and add a second Tree Cable and lighting circuit when needed
  • 3  Mark every light that needs more than the Tree Cable, like a mains connection or a dimmer
  • 4  Supply Tree lights from their own 24 V output and make sure everything shares a common ground
  • 5  Use Tree whenever possible, otherwise Air

That’s really all there is to it.

Want to know more? Read Planning LOXONE Light and check out our LOXONE Essentials tutorials: Wiring Essentials, Distribution Board Essentials and Commissioning Essentials.