How to Dim LED Lamps

Light at home is no longer just a function. It has become a tool for shaping mood, comfort, and energy efficiency. More and more customers expect smooth control over their lighting. At the same time, the market is full of products, and not every LED lamp works with every dimming system. As an electrician and lighting consultant, I see that the biggest issues arise from choosing the right dimming method for a specific fixture and electrical installation.
This article is meant to simplify the topic and walk you through the most popular methods: from basic ON/OFF, to phase-cut dimming, switchDIM, and advanced systems such as DALI and Casambi (AQsmart).

ON/OFF

The simplest option. No dimming.

Many integrated LED fixtures contain a constant-current or constant-voltage driver. Such a lamp operates only in on/off mode.
A standard three-wire installation and a basic single-pole switch are enough.

Pros:
• lowest cost
• no installation complications

Cons:
• no intensity adjustment
• no way to upgrade to dimming later

If a customer expects dimming but has a lamp in ON/OFF version, no wall dimmer will solve the issue. The fixture must be replaced with a model designed for dimming.

Phase-cut dimming

Popular and well-known, but with limitations

Phase-cut dimming (TRIAC, leading or trailing edge) works by cutting part of the AC waveform. It is most commonly used with a rotary wall dimmer.

Installation:
• usually compatible with a standard three-wire setup

Advantages:
• low cost
• easy to install
• works with many traditional light sources

Limitations:
• compatibility depends on the LED driver design
• too many lamps on one circuit may cause buzzing or flicker
• dimming range varies depending on the load

I consider this a compromise solution. It works where simplicity is the priority, but I do not recommend it for premium fixtures.

switchDIM

Dimming via a standard momentary push button

This is a great option for customers who want convenient dimming but do not plan full home automation.

Installation:
• requires a four-wire installation
• the lamp must support switchDIM

Operation:
• short press turns the lamp on/off
• long press dims or brightens the light

Benefits:
• no dimmer needed, only a momentary push button
• intuitive control
• stable performance

Drawbacks:
• not every fixture supports switchDIM
• no advanced light scenes or automation

This is a solution I often recommend to users who want good functionality at a reasonable cost with clean, simple wiring.

DALI

Professional control standard for smart building automation

DALI is an advanced communication bus providing full control over LED lighting. In professional projects, it is my most recommended choice.

Installation:
• requires a five-wire setup
• two wires form the DA+ and DA– communication bus

Capabilities:
• full dimming range from 1 to 100% with no flicker
• one driver can operate multiple fixtures
• grouping, scenes, and automation
• independent control for each individual fixture

DALI does not require a full smart home system. It can also be used with rotary DALI dimmers or in-box DALI drivers.
If the client plans to expand their system or wants complete control, DALI is the most future-proof solution.

AQsmart Casambi

Wireless Bluetooth-based light control

Casambi is currently one of the most convenient systems for homes, apartments, and small commercial spaces. It does not require a central hub or complex infrastructure.

Requirements:
• standard three-wire installation
• a fixture equipped with Casambi or a compatible driver

Control options:
• Casambi app on a smartphone or tablet
• wireless switches and remotes
• scenes, automation, timers

Strengths:
• no wiring modifications needed
• highly stable communication
• system can be expanded without wall modifications
• very user-friendly

I recommend Casambi especially for clients who want modern, flexible, wireless control without committing to a full smart home ecosystem like KNX or Loxone.

Summary

Choosing the right dimming method should never be a guess. It must match the installation, the fixture technology, and the user’s expectations.

• ON/OFF offers simplicity, without dimming.
• Phase-cut dimming is cheap but not always reliable.
• switchDIM is a smart middle ground offering comfort and stability.
• DALI provides professional-level precision and flexibility.
• Casambi enables wireless control with strong convenience and expandability.

If you are planning a new installation or renovation, think ahead. Lighting has become part of daily comfort, and choosing the right dimming system allows you to get the full potential out of your LED fixtures.

If you want, I can help you match the proper dimming system to your lamp and clear up any uncertainties.