NOTE 1 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 standard was published but not necessarily complying with the electrical parameters of this standard may be marked “Suitable for FISCO systems”. This apparatus may be accepted in a FISCO system, if the comparison of the electrical parameters U_o, I_o, P_o, with U_i, I_i, P_i, demonstrate compatibility with the remainder of the system, and all the other requirements of this standard are met.

NOTE 2 A typical system is illustrated in Annex A.

NOTE 3 Generally, “ic” FISCO systems are intended for use in zone 2 locations. FISCO systems are predominantly intended for use in zone 1 and 2 locations, but may enter zone 0 locations if specifically permitted to do so by the documentation.

NOTE 4 Edition 1 of this standard introduced the FNICO concept to cover the use of Fieldbus concepts in zone 2 utilizing the energy-limited [nL] concept. This standard substitutes the “ic” concept for the energy-limited concept, but permits the continued use of FNICO and nL apparatus.