Arc flash: Prevention measures in IEC/EN protection approach

All the safety standards, also if implemented with different philosophies and perspectives, highlight a program to protect against electric shocks, arc flashes and blasts. The European EN 50110 standard emphasizes equipment integrity “giving collective protective measures priority over individual protective measures” that remain such as additional means (Directive 89/391/EEC - OSH). Focusing on the specific hazard of arc flash, many prevention measures are available in the IEC approach of protection program. The main measures, essentially passive, are: the IP code; safety procedures for dead working; MV isolator switches that allow grounding of the working zone without the need of a manual equipment; the tested effectiveness of the switchboard design in protecting persons in case of an internal arc (internal arc class IAC); forms of separation for low voltage switchgear; the standardized method to calculate the minimum value of short-circuits. All these measures assist the risk reduction of the arc flash in the IEC/EN safety approach.