Emergency lighting tests that actually prove something

Emergency lighting needs two tests: a short monthly function test, and a full-duration test once a year. In the United States, NFPA 101 requires a functional test of at least 30 seconds monthly and an annual test for the full 90-minute duration, with written records kept. The annual one is where failures are found, and it is the one most often skipped.

Why the monthly test proves so little

Thirty seconds proves the lamp lights and the changeover works. It says nothing about the battery, which is the component that actually fails. A fitting that lights for thirty seconds and dies after eight minutes passes every monthly test for years and fails when it is needed.

Running the annual duration test

The unit has to run on battery for its rated duration, and at the end the lighting must still be adequate. That means somebody walks the route at the end, not the beginning.

• •Plan it when the building is empty, and tell security and any night staff
• •Isolate the normal supply to the fittings under test
• •Walk the escape routes at the end of the period, not the start
• •Record each fitting as pass or fail individually, not as a floor
• •Allow the batteries to recharge fully before the building is occupied again, and note that the building is at reduced protection until they do

Record fittings individually, or the record is useless

A record that says "level 3 tested, satisfactory" cannot tell you which fitting failed last year or which ones are ageing. Every fitting needs an identity, a location and its own result. Numbering and coding them makes the annual test a walk rather than a hunt.

Batteries fail on a predictable schedule

Emergency lighting batteries have a service life of a few years and they fail in cohorts, because they were all installed at once. Record the installation date on each fitting and expect a wave of failures. Replacing a floor’s worth in one planned job costs far less than chasing them one at a time.

Check the coverage, not just the fittings

A fitting can pass its test while the escape route is inadequately lit, because a wall was built, a door was moved or a shelf unit now blocks the light. Walking the route in the dark is the only way to see this, and it is the part of the annual test that finds problems no schedule would predict.

This describes the United States requirements. Other countries set their own intervals for the same two tests.