Switchgear

Design and hazard

Switchgear concentrates incoming supply, distribution and protective devices of an electrical installation in a confined space. Ageing screw and plug-in contacts, ingress of moisture or dust, and thermally overloaded busbars produce transition resistances that heat up unnoticed and, in the worst case, lead to arc flashes or fires. Protective devices that are not coordinated to recognised design standards can also fail to isolate a fault selectively, letting it affect the whole installation instead.

Protective measures

Key measures are compliance with recognised construction standards for switchgear assemblies, a documented selectivity study of the upstream protective devices, and periodic inspection through visual checks, torque verification of connections and thermographic scanning under operating load. A thermography-friendly design – accessible inspection points, suitable viewing windows – substantially eases in-service checks and is increasingly recommended by loss prevention bodies.

Insurance relevance

Switchgear is a priority inspection item during technical risk surveys, since it can be both the origin of a fire and a weak point for business interruption. Documented maintenance and thermography programmes, together with a traceable protection coordination study, have a favourable effect on risk classification.