Start with the lamp and dimmer model numbers. “Dimmable” describes a capability, not compatibility with every control. Test the proposed combination at the lowest light level the room will use.
Check the driver’s dimming method
An LED needs a driver designed for the control method. Check the permitted supply voltage, leading- or trailing-edge support where relevant, minimum light level, and tested dimmers. Keep these details on the product schedule.
Compare the control arrangements
Phase-cut dimming acts on the supply waveform and is common in lamp replacements. 0–10V uses a separate control connection. DALI provides digital addressing and other supported functions. Choose against the wiring, grouping, and control needs of the project.
| Method | What to confirm |
|---|---|
| Phase-cut | Lamp and dimmer pairing, edge type, load limits, and low-end trim |
| 0–10V | Driver response, wiring, polarity, minimum output, and switch-off method |
| DALI | Supported functions, device records, bus design, addressing, and commissioning |
| Smart lamp | Controller support, network needs, power-loss behavior, and undimmed supply |
Test the low end and startup
Look for flicker, dropout, delayed startup, noise, and lamps that do not restart at a low setting. Check minimum load, maximum LED load, lamp-count limits, and inrush guidance. Adjust the low-end trim only within the manufacturer’s instructions.
Keep smart lamps on the intended supply
Most smart bulbs use their own dimming electronics and need an undimmed supply. Confirm controller or app support, network requirements, behavior after power loss, and whether local controls work without internet access.
Check ceiling fans and three-way sockets
For a fan, use lamps suitable for its socket, enclosure, vibration, and wattage limit. A three-way lamp and socket have a particular contact arrangement; use the combination specified by the lamp and fixture manufacturers.
Approve a sample circuit
Test the planned lamp count on the actual control, including startup at minimum output and a period of operation. Record lamp model, driver, dimmer, settings, and test result. Require review if the supplier changes any of those parts.
Frequently Asked Questions
Are all LED bulbs dimmable?
No. Check the lamp marking and datasheet, then verify the compatible control method and tested combinations.
Why do lamps flicker when dimmed?
Possible causes include an incompatible control, insufficient load, settings outside the stable range, wiring faults, or a failing component. Check the approved combination and have electrical faults assessed by a qualified person.
Does 0–10V guarantee dimming to off?
No. Minimum output and off-state behavior depend on the driver and control. Specify and test the behavior needed.
