Tools
Dimming compatibility checker
Most dimming complaints are a protocol mismatch, not a faulty fixture. Pick the driver and the control and see what you should expect.
This one has its own page too — dimmer compatibility checker — and the full explanation of forward phase, ELV, 0-10V, DALI and PWM is in the lighting controls guide.
Most dimming complaints — flicker, buzz, a lamp that will not go below half, a bank that drops out all at once — trace back to a mismatch between the load and the control. The pairings are not interchangeable, and some of them are actively damaging rather than merely disappointing.
The two that cause real harm are worth memorising. A magnetic low-voltage transformer must be dimmed on forward phase; reverse phase can introduce a DC component and cook it. An electronic low-voltage transformer is the opposite, and forward phase on one causes buzzing and early failure. Getting these backwards is a warranty call rather than an adjustment.
The other thing that catches people is minimum load. Dimmers were designed for incandescent circuits drawing hundreds of watts, and many still specify a minimum. Replace six 60-watt lamps with six 9-watt LEDs and the circuit that drew 360 watts now draws 54, which can fall below what the dimmer needs to operate. The symptom looks like a faulty lamp and is actually a control problem.
Before you rely on it
This is arithmetic, not a photometric calculation. It will get you to a sensible starting point and tell you when something is obviously wrong, but a real layout gets run in AGi32 against the actual IES files. Send me the plan and I will run it properly.