Visual inspection and identifying non-compliance and deterioration
Look before you test
Visual inspection is the highest-yield part of a periodic inspection: most defects found in service are visible. Inspect with the installation isolated and safe, working systematically from origin to final circuit.
Check the origin and distributor's equipment; consumer units and distribution boards - device ratings and types, enclosure condition, blanking, labelling; main protective bonding of incoming metallic services (water, gas, oil, structural steel) with the correct conductor size, a sound connection, and on a PME supply within about 600 mm of the point of entry; circuit protective conductors present and connected; cable types, routes, support and protection; accessories - cracked, damaged, missing lids, wrong IP rating, thermal damage, scorching, loose terminations; fire sealing of penetrations; danger and warning notices, RCD notices, the periodic inspection label and the notice at the origin.
Deterioration includes discoloured insulation, verdigris, corrosion, water ingress, rodent damage, chafed sheaths and loose terminations.
Traps. Missing or undersized main protective bonding is a common high-code observation, often C2. Bonding applies to extraneous conductive parts, not to every pipe. Exposed live parts are C1 and must be made safe immediately, with the client's authority.
Worked example. A 6 mm2 bonding conductor is fitted to the incoming gas pipe with a loose clamp and a corroded connection 2 m from the meter: bonding is present but not secure and may be undersized for a PME supply - record it and code C2.