NAPIT highlights severe EICR failures involving stripped SWA armouring and overloaded neutrals supplying caravan sites and electric showers.
The technical team at NAPIT has highlighted a severe electrical installation failure in its latest Codebreakers series, demonstrating the risks of compromised cable armouring and shared neutrals. The case study involves a 3-core 16 mm² Steel Wire Armoured (SWA) cable where inspectors discovered the protective outer armouring had been completely unwound to facilitate entry into a building structure.
Alongside the physical damage to the cable's mechanical protection, the installation presented severe thermal overload risks. The single neutral conductor was tasked with carrying the combined load of a 9 kW electric shower within a dedicated shower block as well as the active supply hook-ups for a six-pitch caravan site. Such configurations breach fundamental BS 7671 standards regarding current-carrying capacity, protective grounding, and structural containment.
Unwinding SWA armouring strips an installation of its vital earthing path and mechanical shielding. SWA cables rely on intact armour wire clamped securely via proper SWA glands to guarantee circuit protective conductor (CPC) continuity and to guard against physical impact. Exposing inner cores at the point of entry creates immediate shock and fire hazards, particularly in high-moisture outdoor environment settings like campsite shower facilities.
Furthermore, combining heavy heating loads with multiple sub-supplies on a single neutral risks overheating the conductor, breakdown of insulation, and structural fires. When electrical contractors conduct periodic inspection and testing (EICR), defects of this magnitude command immediate C1 (Danger present) or C2 (Potentially dangerous) classification codes, requiring urgent remedial action before the installation can be deemed safe for continued operation.
What does this mean for a UK tradesperson or DIYer actually buying this kit — does it change what they should pay, buy, or watch out for?
For electricians and site managers sourcing materials from merchants such as Screwfix, Toolstation, or Travis Perkins, this case emphasizes why cutting corners on cable entry accessories is never worth the risk. Electricians must ensure they purchase correct brass SWA glands (such as BW for internal or CW for external weatherproof terminations) matched precisely to the 16 mm² cable size, along with appropriate IP-rated enclosures. Attempting to fit oversized SWA cable into inadequate consumer units or knockouts by unwinding protective armouring invalidates manufacturer warranties and violates wiring regulations. Stocking proper gland kits, earth tags, and suitable distribution boards before starting high-load commercial or outdoor projects prevents costly callbacks and dangerous retrofits.
Reported by Professional Electrician — original article
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