IEEE C57.13.3-1983 pdf free.IEEE Guide for the Grounding oflnstrument Transformer SecondaryCircuits and Cases.
IEEE C57.13.3 emphasis of this guide is personnel safety and proper performance of relays at powerline frequencies.Thegrounding and shielding of cables and other grounding considerations are not addressed.However, references dealingwith these and related subjects are included in the Bibliography.
Historically, it has been common practice in the US to connect some part of the secondary circuit of voltage andcurrent transformers to the station ground system.The present preferred practice is to locate this safety ground withsuitable ground isolation test facilities at the first point of application (switchboard or relay panel) of the instrumenttransformer secondary circuit. The circuit ground isolation facilities will permit convenient testing of circuit insulationto ground.
Previous publications have made significant contributions to consistency in some areas of grounding practices. Thisguide will include those contributions that are generally practiced today, make revisions where present experience andpractice indicate them to be desirable, and make recommendations in new areas of interest not previously addressed.Diagrams are included to illustrate the recommendations.
This guide contains general and specific recommendations for grounding current and voltage transformer secondarycircuits and cases of connected equipment. The practices recommended apply to all transformers of this type,including capacitive voltage transformers and linear couplers irrespective of primary voltage or whether the primarywindings are connected to, or are in, power circuits or are connected in the secondary circuits of other transformers asauxiliary cts or vts. Although most diagrams included in this guide show relaying applications，the recommendedpractices apply equally to metering and other areas where instrument transformers are used.
Exceptions to grounding are permissible or sometimes required where advantages obtained by not grounding,incertain instances or in certain types of installations, are considered to outweigh the safety or other advantages obtainedby grounding.Such exceptions should comply with the recommendations of ANSIC1-1987 [1]’, even though utilitiesare presently exempt from the requirements of this code.IEEE C57.13.3 pdf download.