Section
Selection & calculation
Choosing drivers, dimming protocols, ingress ratings and emergency gear, and the arithmetic that decides whether a specification survives contact with a site.
Choosing a dimming protocol: 0–10 V, DALI-2, DMX512, phase-cut and wirelessWhat each dimming interface can and cannot do, the wiring and topology mistakes that break each one, why commissioning labour rather than hardware cost usually decides, and the boundaries where one protocol stops being the right answer.
Emergency lighting: what the standards require, and why this one needs an engineerThe illuminance, duration and response-time requirements that define an emergency scheme, the difference between maintained and non-maintained operation, the testing regime that keeps it legal, and the specific reasons this is not a specification to assemble from a website.
IP and IK ratings: what they test, and the four ways outdoor fittings fail anywayWhat each IP digit is actually tested against, why a higher second digit does not always include the lower ones, the breathing mechanism that fills sealed housings with water over years, and the corrosion and UV requirements that no IP number covers.
Matching a driver to an LED load, and the inrush problem nobody sizes forConstant current versus constant voltage, why the compliance voltage window has to hold at cold start as well as hot, why paralleling strings on a CC driver fails, and the inrush current that decides how many drivers you can put on one breaker.
What a "50,000 hour" LED claim is allowed to meanHow LM-80 measurement and TM-21 extrapolation actually produce a lifetime figure, the 6× rule that caps how far a claim may be projected, why the number describes an LED package rather than a luminaire, and the component that usually fails first anyway.