Dynamic elaboration on the Art & Science of Hazardous Area Protection
nA = non-sparking apparatus
nC = fittings and components
nR = restricted breathing
The idea is to use or design such electrical equipment which cannot ignite an explosive atmosphere surrounding it (during normal operation and under defined abnormal operating conditions).
For Zone 2 applications there is an option different from Zone 1 referred to as a type of protection “n,” sometimes called “Ex-n” or non-sparking. Type “n” apparatus is standard industrial equipment which in normal operation will not produce arcs sparks or surface temperatures high enough to cause ignition. The apparatus has an IP rating called Ingress Protection which is similar to NEMA enclosure ratings such as NEMA 4, hose-tight. A non-incendive component is limited in use to the particular circuit for which it has been shown to be non-ignition capable. Unlike intrinsic safety, there is no restriction on the energy levels.
|Non-Sparking (Zone 2)||AEx nA||US||Class I, Zone 2||ISA 60079-15|
|Non-Sparking (Zone 2)||Ex nA||CA||Class I, Zone 2||CAS E60079-15|
|Non-Sparking (Zone 2)||Ex nA (EEx nA)||EU||Zone 2||EN 60079-15|
|Ex nA||IEC||Zone 2||IEC 60079-15|
|Non-Incindive (Division 2)||(NI)||US||Class I, Division 2||FM 3611|
|Non-Incindive (Division 2)||(NI)||CA||Class I, Division 2||C22.2 No. 213|