Electrical apparatus for explosive gas atmospheres – Part 27: Fieldbus intrinsically safe concept (FISCO)
|Publication Date:||1 November 2002|
|ICS Code (Electrical apparatus for explosive atmospheres):||29.260.20|
This part of IEC 60079, which is a technical specification, contains the details of apparatus, systems and installation practice for use with the Fieldbus intrinsically safe concept (FISCO) and is based on the concepts of Manchester encoded, bus powered systems designed in accordance with IEC 61158-2 which is the physical layer standard for Fieldbus installations. The constructional and installation requirements of FISCO apparatus and systems are determined by IEC 60079-11, IEC 60079-25 and IEC 60079-14, except as modified by this specification.
Certification to the FISCO requirements does not prevent apparatus also being certified and marked to IEC 60079-11 in the conventional manner so that they may be used in other systems. Some apparatus certified before this technical specification was published but not necessarily complying with the electrical parameters of this technical specification may be marked 'Suitable for FISCO systems'. This apparatus may be accepted in a FISCO system, if the comparison of the electrical parameters Uo, Io, Po with Ui, Ii, Pi demonstrate compatibility with the remainder of the system, and all the other requirements of this technical specification are met.
A typical FISCO system is illustrated in Figure 1.