2-Way 10-150W Intelligent Dimmer Module - White (5-150W LED)

The Knightsbridge GDM150IU is a 2-way intelligent dimmer module designed for Knightsbridge grid wiring systems, including Screwless, Flat Plate, Raised Edge and Metal Clad ranges. The module handles 10-150W incandescent and mains voltage halogen loads, 10-150W low-voltage halogen with electronic transformers, and 5-150W dimmable LED loads. A push on/off mechanism sits above a rotary control that adjusts light level across the full dimming range.

The intelligent switching between trailing edge and leading edge modes happens automatically based on the connected load, removing the need for manual configuration or mode selection. Trailing edge suits most dimmable LEDs and electronic-transformer low-voltage halogen, while leading edge handles traditional incandescent and magnetic-transformer halogen. The module detects the load type on power-up and selects the appropriate dimming waveform to minimise flicker and buzzing.

Built-in protections include overload cutoff, over-temperature shutdown, and an inrush current limiter that manages the startup surge when switching on multiple lamps simultaneously. The module fits a standard 35mm minimum back box depth and occupies one module width (25mm) within a Knightsbridge grid system, allowing it to be combined with other grid modules — sockets, switches, data ports — within the same faceplate.

The white finish on the rotary control and push mechanism matches the white module housing. Knightsbridge recommends a maximum of 10-12 lamps per dimmer to stay within safe inrush current limits, particularly when dimming older LED or CFL loads that draw higher startup current than their running wattage suggests.

Product Specification Sheet

Product Manual

What's the difference between leading edge and trailing edge dimming?

Leading edge cuts the front of the AC sine wave and suits traditional incandescent and magnetic-transformer halogen loads. Trailing edge cuts the back of the sine wave and suits dimmable LEDs and electronic-transformer halogen. This module detects the load type and switches mode automatically, so no manual configuration is needed.

Is it compatible with all dimmable LED bulbs?

The module works with most dimmable LED bulbs rated 5-150W total load, but not all LEDs dim smoothly on all dimmers due to variations in LED driver design. Knightsbridge recommends testing with your specific bulb before final installation, particularly with older or budget LED models.

Can it be used in a 2-way switching circuit?

Yes. The GDM150IU is a 2-way dimmer module, meaning it can be wired into a circuit with a second switch position elsewhere that also controls the same light. Both positions will turn the light on/off, but dimming adjustment is only available at the dimmer module location.

What back box depth is required?

A minimum 35mm back box depth is required. The module itself projects 23mm from the grid frame, and the recessed depth into the back box is 22mm, so the total installation depth matches standard UK single-gang back boxes.