What is functional testing?
Operating checks on the live system — proving every circuit, brightness step and control does what the design requires, not just that it powers up.
Functional testing follows energisation. With the system live and stable, each circuit is operated the way it will be used: the right fixtures light, in the right colour and direction, every brightness step responds, and every control point works.
Indications, alarms and operating modes are checked too, and each result is recorded. A defect is isolated, fixed and re-tested. When the checks pass, the system is ready for integration. Light output is not measured here; that is a separate photometric exercise.
- Circuits. Select each circuit; confirm the right fixtures light, in colour and direction.
- Brightness. Step through every setting and confirm even response.
- Controls. Operate from each local and remote control point.
- Monitoring. Check status indications and alarm responses.
- Sequences. Test flashing, sequencing and stop-bar selection where fitted.
- Record. Log each result; isolate, fix and re-test any defect.
Frequently Asked Questions
Q1What is functional testing in airfield ground lighting?
A set of operating checks on the energised system that prove it does what the design requires: each circuit lights the right fixtures, every brightness step responds, and controls, indications and operating modes work. It follows energisation.
Q2How is it different from energisation?
Energisation shows the circuit can run live safely and steadily. Functional testing goes further and checks that each circuit, step and control actually performs its intended function, the way operators will use it.
Q3What is normally tested?
Circuit selection, which fixtures light and in what colour and direction, each brightness step, local and remote control, selector switches and interlocks, status and alarm indications, and flashing, sequencing or stop-bar selection where the design includes them.
Q4Is photometric testing part of functional testing?
No. Functional testing confirms that lights come on correctly and respond to control. Measuring light intensity, beam and colour against the standard is a separate photometric exercise.
Q5Why test every control point?
Each control point, local or remote, has its own wiring, settings and priority. Operating from each one, as a controller would, exposes wiring, labelling and configuration errors that a single-point test would miss.
Q6What happens if a function fails?
The defect is recorded, the circuit is isolated, the cause is found and corrected, and the affected checks are repeated. The record shows the failure, the correction and the passing re-test.
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