What is cable inspection?
A visual and physical check of the cable route and every point you can reach on it, done before the electrical tests, so damage and moisture are found before they become faults.
Most AGL cable is buried, so a cable inspection concentrates on the places that can be seen: the route above the cable, the pits and manholes, joints and connectors, any exposed duct or sheath, and the earth bonds. It is a hands-on check and a regular part of the maintenance programme. Walking the route can be done first, but pits and connectors are opened only with the circuit isolated, locked out and proved dead.
Inspection often finds the cause of a poor test reading, such as water standing in a pit or a corroded connector, which is why it comes first. Each defect is photographed and logged against its circuit and location so the next inspection can show whether it is getting worse.
- Isolate. Circuit off, locked out and proved dead before any pit or connector is opened.
- Walk the route. Check markers and the ground above for settlement, digging or new works.
- Open pits. Look for water, silt, debris and damaged lids. Treat deep pits and manholes as confined spaces.
- Check duct and sheath. Cuts, crushing, heat damage, strain at bends.
- Check joints, connectors and earthing. Corrosion, looseness, heat marks, cracked sealing, missing bonds.
- Record & act. Photograph, log, raise repairs, restore and re-test where needed.
Frequently Asked Questions
Q1What is cable inspection in airfield lighting?
A visual and physical check of the cable route and the accessible points along it, including markers, pits, joints, connectors, ducts, sheath and earthing, carried out as part of routine maintenance.
Q2Why is inspection done before testing?
It finds obvious causes, such as water in a pit or a corroded connector, and makes sure the circuit is safe to test. Findings also show where to focus the electrical tests.
Q3Does the circuit have to be isolated?
Yes for opening pits and handling connectors. The circuit is switched off, locked out and proved dead under the site permit-to-work procedure before any work starts.
Q4What are the common defects?
Water or silt in pits, corroded or loose connectors, damaged sealing, cuts or crushing of the sheath or duct, and missing or corroded earth bonds.
Q5How are findings recorded?
Each defect is logged against the circuit and location with a dated photograph and the action taken, so later inspections can show whether it is stable or getting worse.
Q6How often should cables be inspected?
The interval is set by the airport’s maintenance programme and the national authority’s guidance, and may change with the age and condition of the circuit.
Q7Are there special hazards in pits and manholes?
Yes. Deep pits and manholes can be confined spaces with standing water, silt, poor air or gas, and may sit beside live cables on other circuits. Follow the site's confined-space and permit-to-work rules, and never enter a flooded pit.
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