⚡ Dimmer switch
Dimmers derate in multi-gang boxes
TRIAC / Forward phase dimmer: The most common dimmer type. Works well with incandescent and many LED bulbs. LEDs must be explicitly rated “dimmable” — non-dimmable LEDs will flicker, fail early, or not dim at all. LED dimmers have a lower effective maximum (typically 75–80% of rated W for LED loads).
💡 Fixtures on this dimmer
Fixture / lamp name
Watts each
Load type
Tip: Enter watts printed on the bulb or fixture label, not the “equivalent” wattage.
Compatibility confidence meter
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Flicker risk
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Effective max load (derated)
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Safety headroom
⚠️ Likely symptoms with this configuration
Recommendations
Dimmer technology — quick reference
TRIAC / Forward phase
Most common. Cuts the leading edge of the AC wave. Works with incandescent and dimmable LED. Many older TRIAC dimmers cause LED flicker — check LED compatibility list.
ELV / Reverse phase
Cuts the trailing edge of the AC wave. Quieter, smoother dimming for electronic drivers and many LED drivers. Preferred for ELV fixtures.
MLV — Magnetic LV
For magnetic (iron-core) transformers. Do not use with electronic drivers — will cause buzzing, overheating, and damage.
Smart dimmers (no neutral)
2-wire smart dimmers “steal” current through the load to power themselves. This causes ghost glow and flicker on LED at low dim levels. Neutral wire strongly preferred.
Design guidance only. Dimmer compatibility depends on specific product combinations. Always check your dimmer manufacturer’s compatibility list before installation. Consult a licensed electrician for wiring.