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In short: Match constant voltage or constant current, use a dimmer rated for LEDs, and size the control for inrush. A ceiling fan is a motor, not a lighting load.
What to look for
- Constant voltage or constant current. A label in volts, usually 12 or 24 volts DC, is a constant-voltage driver for LED tape and products that limit their own current. A label in milliamps, such as 350, 700, or 1050, is a constant-current driver for modules built for a set current. The LEDs and the driver have to ask for the same type.
- Dimming method. The method printed on the driver has to match the control: a 0–10V pair, phase-cut on the line, or a digital bus. A phase-cut wall dimmer does not drive a 0–10V input, and a 0–10V slider does not dim a phase-cut driver.
- An LED rating and a minimum load. Many dimmers were listed for incandescent lamps. LEDs need a dimmer listed for LED drivers. Under that dimmer's minimum load, the lamps flicker or drop out. A low-end trim, when the dimmer offers one, keeps the bottom of the travel usable.
- Inrush. Drivers draw a short spike, often many times the running current, at the moment power is applied. A dimmer or relay sized only for steady watts can buzz, run hot, or weld its contacts. Compare the driver's inrush note with the control's LED rating, and split a large group across more than one control.
- Ghosting. LEDs light on very little current. A dimmer or smart switch that powers itself through the lamp, or a lighted locator, can leave a faint glow when the switch is off. The usual fixes are a neutral if the device needs one, the bypass the maker specifies, or a plain switch. If the switch is landed on the neutral instead of the hot, the fixture stays energized. That is a shock hazard.
- Fan loads, separately. A light dimmer is listed for lamps. A ceiling fan is a motor and wants a fan speed control rated for that fan. Dim a light kit on its own control. Many DC-motor fans only run properly on the control they shipped with.
Common mistakes
- Pairing a constant-voltage driver with constant-current modules, or the reverse. The LEDs overheat, fail early, or never light correctly.
- A phase-cut dimmer on 0–10V drivers, or a 0–10V control on phase-cut drivers.
- An incandescent-only dimmer on LEDs, or a load under the dimmer's minimum, which shows up as flicker.
- So many drivers on one dimmer or relay that inrush makes it buzz or welds the contacts shut.
- Replacing lamps over and over while a no-neutral dimmer is leaking through them and causing the glow.
- One lamp dimmer running both a ceiling fan and its light kit.
Shop dimming controls on eBay
General buying advice only. This guide does not speak for any manufacturer, and it names no brands or part numbers. The shop is separate.
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