Dimmable LED that actually dims properly

2 min read ·

Almost every complaint about LED dimming is written as a complaint about the lamp. It is nearly always a mismatch between three things: the lamp’s driver, the dimmer, and the size of the load on the circuit.

Leading edge and trailing edge

Old dimmers were built for filament lamps and cut the leading edge of the mains waveform. Most LED drivers prefer trailing edge control, which is gentler on their electronics. Put an LED on an old leading-edge dimmer and you get flicker at the bottom of the range, audible buzz, or a lamp that simply drops out below forty percent.

Minimum load is the trap

Dimmers have a minimum load as well as a maximum. Replace six 60W filament lamps with six 6W LEDs and the circuit load falls from 360W to 36W, which may be below the dimmer’s floor. The symptom is flickering or a lamp that will not turn off cleanly, and the cause is that there is not enough load for the dimmer to regulate against.

"Dimmable LED" is not a specification. The only reliable guide is the manufacturer's compatibility list pairing that lamp with that dimmer.

Check compatibility, not category

Manufacturers publish compatibility lists pairing specific lamps with specific dimmers, and those lists are the only reliable guide. Where a room mixes lamp types, give each type its own dimmer rather than sharing a channel.

Dimming to zero

If you want a smooth fade all the way down, look for lamps rated for deep dimming and pair them with a dimmer that has a trim adjustment. Setting the trim correctly at commissioning is what removes the last of the flicker, and it takes about five minutes per circuit.

What we do on site

We bring sample dimmers, test against your actual lamps before committing, and set the trim on every channel before handover.

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Open the panel door, photograph the label, and we will tell you the make, the age, and whether it needs replacing.

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