The different types of protection - constructional requirements

By no means will this chapter claim to fill a standard s place. Therefore, a very careful reading of standards is recommended and in case of any need for clarification the testing houses or notified bodies should be asked for interpretation. 

This chapter will seek to answer the question Why do standards ask for specified temperatures of windings, for limited gap and joint values and for restricted voltages and currents in electric circuits The following intends to clarify the physical background of the standards technical content, to explain the methods of explosion protection in electrical engineering, and demonstrate modem explosion protected apparatus to give an appreciation of the bandwidth of the different types of protection. 

To start with the latter Figs 6.1-6.8 give an impression of environmental conditions at the place of duty for modem explosion protected equipment, and at the same time, they may anticipate its efficiency and power as well as its broad range of application. 

Type of protection EEx pde[ib] IICT3 Rated power 10 800kW Rated voltage 3kV Purging volume 10.8 m3. 

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