Chapter 12 Ex Protection Concepts

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Session 12 Ex Protection ConceptsEx Protection ConceptsElectricalElectrical Symbol Typical IEC EPLTypical Zones IEC Standard Basic concept of protectionIncreased safety e Gb 1,2 IEC 60079 7 No arcs, sparks or hot surfaces. Enclosure IP54 or betterType n (non sparking) nA Gc2 IEC 60079 15Flameproofd Gb 1,2 IEC 60079 1 Contain the explosion, quench the flameType n (enclosed break) nC Gc2 IEC 60079 15Quartz/sand filled q Gb 1,2 IEC 60079 5Quench the flameIntrinsic safety ia Ga 0,1,2 IEC 60079 11Limit the energy of sparks and surface temperaturesIntrinsic safety ib Gb 1,2 IEC 60079 11Intrinsic safety ic Gc2 IEC 60079 11Type n (energy limitation)nL Gc2 IEC 60079 15Pressurised (up to 2007)

enclosures are: ingress protection to at least IP 54 and ... maximum voltage rating. • Temperature limitation • Current de‐rating of the terminals (and conductors) of 50%. The equipment of Ex terminal boxes with terminals and cable screw‐connections is subject to …

  Protection, Ratings, Singer, Ingress protection