AGL Cable Protection for Airfield Lighting Cables

Cable protection systems support the long-term reliability of airfield electrical installations by protecting cable routes and connection areas. They help reduce the risk of mechanical damage, environmental exposure and installation-related stress across runway, taxiway and field infrastructure, and are selected according to cable type, installation environment, physical exposure and the interface with associated lighting equipment.

Typical applications are cable crossings, exposed cable sections, equipment interfaces, field cable routes, connections to airfield lighting equipment, cable approaches to junction pits and handholes, areas requiring additional mechanical protection, new AGL installations, and maintenance and rehabilitation projects.

AGL cables can be exposed to mechanical stress during installation, maintenance and operation of the surrounding airfield infrastructure, and protection adds a layer where the route needs enhanced resistance to impact, abrasion, crushing or other installation-related hazards. At crossings consider it together with cable type and diameter, crossing location, installation depth, expected mechanical loading, duct arrangement, pavement construction, drainage and existing underground services. Where a duct is used, additional protection may be needed at transitions, entries and other vulnerable points.

Protection helps safeguard short exposed sections against accidental impact, abrasion, installation damage, environmental exposure, contact with surrounding structures and maintenance-related disturbance, while keeping the cable accessible for inspection. It is also important where cables transition between underground routes and equipment such as elevated light bases, inset light assemblies, junction boxes, junction pits, handholes, cable ducts and transformer connections, coordinated so that cable bending, routing and connection requirements are maintained.

Select protection to suit the cable outside diameter, number of cables, required bend radius, routing arrangement, connection type, protection length and available installation space, without restricting the cable beyond its permitted installation requirements. The material should suit the installation environment, including moisture, temperature variation and soil conditions, and drainage and water management should be considered for underground protection.

Confirm the cable type and dimensions, protection requirement, installation location, required protection length, mechanical exposure, environmental conditions, interface with ducts, pits or handholes, cable bending and routing requirements, accessibility for maintenance and applicable project requirements. Protection must not remove or compromise route features required by the project design, such as burial depth, concrete-encased ducts under pavements, cable warning tape or markers, and any counterpoise (lightning-protection) conductor laid with the cable route.

Ducts provide the primary protected pathway, while additional protection is applied at exposed sections, transitions and equipment interfaces to maintain continuity of protection along the route. Joints and splices can need additional protection, compatible with the selected Joint / Splice Kit and accessible for inspection where required. For series-circuit installations, protection can be coordinated with the primary cable route and associated connectors, transformers and field equipment while allowing access for testing and maintenance.

Yes. It can be used during airport rehabilitation and maintenance projects where existing cable routes require additional protection or replacement. Before replacement, assess the existing cable condition, routing, installation depth and surrounding infrastructure to determine the appropriate protection arrangement.

Protected routes should be included in relevant airfield electrical inspection and maintenance. Check the physical condition of the protection, signs of cracking, deformation or damage, cable exposure, equipment interfaces, cable entry and exit points, water or contamination ingress, security of protective components and compatibility with ongoing cable maintenance. Damaged protection should be assessed and replaced where necessary to maintain the required level of cable protection.

Treat every AGL cable as energised. Damaging, cutting or disconnecting an energised series-circuit cable can cause serious injury or death, because an open series circuit driven by a constant-current regulator can produce dangerously high voltage. Locate and mark cable routes from as-built drawings and a cable locator before any excavation or protection work, and never cut, strip, disconnect or open an AGL cable until the circuit is de-energised at the regulator, locked out and tagged, and verified de-energised. See the electrical safety warning on this page.

Treat it as live, keep clear and report it to the airport electrical team. Work only under the airport's permit-to-work system, using qualified personnel and approved procedures. Damaged protection should then be assessed and replaced where necessary.

Depending on the project, references may include ICAO Doc 9157 Part 5 (Electrical Systems) and ICAO Annex 14 Vol. I Chapter 8, FAA AC 150/5340-30J, FAA AC 150/5345-7F (L-824 underground electrical cable for airport lighting circuits), FAA AC 150/5370-10 (cable and duct-bank items), and airport operator, DGCA and project specifications with applicable national electrical regulations. Material, dimensions, mechanical protection, temperature range and installation method should be confirmed for the specific application, and the current edition of each reference confirmed before use.