Engineering notes
Emergency lighting: not the same as the task lights
Highbays that die with the mains are not escape lights. Battery, duration, pictogram — their own lines.
A hall has eighty highbays. The fire file asks for escape lighting. The take-off says “use the highbays, there is a main UPS”. If that UPS is out of scope or does not feed the escape row, the corridor is dark. Escape luminaires are a different article: a battery in the fitting or a central pack, a duration (often one to three hours), a pictogram if it is an exit sign.
Do not bury them in the “workshop lighting package”. Check charge voltage, a test button, and a model you can actually test. DALI emergency is its own family — not a normal driver.