What is an upgrade?

A planned change that improves what an AGL asset or system can do beyond its original specification, for example adding monitoring and control, increasing capacity, adding functions, or moving to newer equipment of a different type. It changes capability, not just condition.

Refurbishment renews a worn asset to near-original condition and performance. An upgrade deliberately changes or improves performance, capability or features, so the asset can do something it could not do before. An upgrade may reuse parts of the existing system.

AGL assets work together on shared circuits, regulators, transformers and control systems. A change in one place, such as a different load, different equipment type or new monitoring, can affect circuit current and loading, regulator suitability, control interfaces and mixed-equipment behaviour. For example, replacing halogen lamps with LED units greatly reduces the load on a series circuit, which the constant current regulator and isolating transformers must still support: check the regulator's minimum load, its current regulation and power factor, and the transformer load ratings. Compatibility is checked at design stage, not discovered on site.

Usually yes. A change to a lighting system is normally handled through the aerodrome's change management and safety risk assessment and, where required, the regulator, and the equipment should meet the applicable standards for its use. The aerodrome's procedures and the regulator decide what approval and notification (for example, of lighting outages during the work) are needed.

The changed equipment and the circuits it affects are tested and commissioned against the design requirements, typically electrical checks such as insulation resistance and circuit current, correct operation and control, monitoring indications and, for lights, photometric performance and alignment where relevant. Some changes also need inspection or acceptance by the regulator before use. Acceptance criteria come from the design, the manufacturer, the aerodrome procedures and the applicable standards.

Drawings and as-built records, equipment and configuration data, maintenance and spares plans, procedures, and staff training. Without these, the airfield is left with a system nobody can maintain confidently, and asset planning loses an accurate picture of what is installed.

Replacing a failed or worn item with an equivalent one is repair or replacement, not an upgrade. It becomes an upgrade only when the change adds capability or performance the asset did not have before, such as new monitoring or a different equipment type.