This guide describes the testing of fault current limiters (FCLs) operating on condition-based impedance increase for AC systems 1000 V and above. This guide does not include constant impedance series reactors and single fuses. (For standards specific to these fault current limiting devices@ see IEEE Std C57.16?1@2@3 and IEEE Std C37.46? [B14]4). NOTE??Testing of FCL load current interrupting capabilities are not addressed in this guide and may be discussed between user and manufacturer.5 Purpose This guide provides guidelines for testing of fault current limiters (FCLs) operating on condition-based impedance increase for AC systems 1000 V and above. 1 Information on normative references can be found in Clause 2. 2 IEEE publications are available from the Institute of Electrical and Electronics Engineers (http://standards.ieee.org/). 3 The IEEE standards or products referred to in this clause are trademarks of the Institute of Electrical and Electronics Engineers@ Inc. 4 The numbers in brackets correspond to those of the bibliography in Annex C. 5 Notes in text@ tables@ and figures of a standard are given for information only and do not contain requirements needed to implement this standard.