This standard applies to single-phase instrument transformers of a nominal system voltage of 115 kV and above with capacitive insulation system for line-to-ground connection and for both indoor and outdoor application. This standard is intended for use as a supplement to IEEE Std C57.13 and as a basis for performance and safety of equipment. It also describes test sequences, criteria, methods and documentation for the test. The purpose of this standard is to supplement the IEEE Std C57.13 - IEEE Standard Requirements for Instrument Transformers with specific requirements to single-phase instrument transformers of a nominal system voltage of 115 kV and above, with capacitive insulation system for line-to-ground connection and for both indoor and outdoor application. Revision Standard - Superseded. Single-phase instrument transformers of a nominal system voltage of 115 kV and above with capacitive insulation system for line-to-ground connection and for both indoor and outdoor application are discussed in this standard. This standard is intended for use as a supplement to IEEE Std C57.13-2008 and as a basis for performance and safety of equipment. It also describes test sequences, criteria, methods and documentation for the test.