In this new 26 page Application Guide AG310 the well known guru Chris Towle explains the philosophy of Zone 2 apparatus and how extra low voltage Ex nA certified instrumentation may be safely installed in these low risk areas. Current ATEX and IECEx standards are discussed together with installation practice, constructional requirements, documentation and routine inspection. Of particular interest is the use of Ex nA certified apparatus with instruments using other protection techniques. Chris shows how an Ex nA loop powered indicator in Zone 2 may be used to monitor the output from a Zone 1 Ex d transmitter, simplifying installation and reducing cost.
Although using BEKA 4/20mA loop powered indicators to illustrate recommended installation practice, the examples apply to most low voltage Ex nA apparatus.
Copies of this Application Guide may be downloaded from the BEKA associates website http://www.beka.co.uk/ag310.pdf or requested by phoning the BEKA sales office 01462 438301.
