Grouping and classification of explosion protected electrical apparatus

Grouping and classification of explosion protected electrical apparatus 

Recalling Chapter 1, there are mainly three specific values for combustible gas- (vapour-, mist-) air mixtures to be considered in order to avoid ignitions of these mixtures  

Very generally, it is considered as quite uneconomical to construct and build explosion protected apparatus in such a way that all specific values mentioned above are met jointly at their lower limits. 

It must be emphasized that the determination of the ignition temperature according to IEC 60079-4 includes selected conditions (surface shape, area, 

Part B According to NEC, National Electrical Code, USA, and CEC, Canadian  

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