IEEE C57.13.5-2009 pdf free.IEEE Standard for Performance and Test Requirements for Instrument Transformers of a Nominal System Voltage of 115 kV and Above.
For the purposes of this document, the following terms and definitions apply.
Dictionary: Glossary of Terms & De/initions should be referenced for terms not defined in this clause.6
capacitise insulation system: An arrangement of internal insulation and electrodes to distribute both the alternating and impulse voltages along the bushing of the instrument transformer with capacitive dielectric layers and/or electrode(s) to achieve an improved co-ordination between the internal and external insulation for the purpose of increasing the over-voltage withstand capability.
Internal arc protection class I: A special transformer design with a feature that, during an internal line—to- ground arc test with the are taking place at a location, which is technically the most probable, the debris of the transformer will be confined to a circle, centered at the transformer. The diameter of this circle is equal to the sum of twice the height of the transformer and the diameter of the transformer.
Internal arc protection class II: A special transformer design with a feature that, during an internal line- to- ground arc test with the arc taking place at a location, which is technically the most probable, will not fracture the insulator or housing of the transformer.
IEC publications are available from the Sales Department of the International Electrotechnical Commission. Case Postalc 131. 3 rue deVarembe. Cl 1-1211. Geneve 20. SwitzerlandSuisse. (http:.www.iec.chI).
lUFF publications arc available from thc Sales Department, the Institute of Electrical and Electronics Engineers. 445 Hoes 1.ane. P.O. Box 1331. Piscataway. NJ 08855-1331. USA (http:1standards.ieee.org/).
‘NEMA publications arc available from the Sales Department. National Electrical Manufacturers Association. 1300 North 17” Street. Suite 1847. Rosslvn. VA. 22209. USA. (http:/’www.ncma.or/).
NOTE—The above definitions regarding the clasiticaiion Internal arc protection class I and Internal arc protection (‘lass ii regarding the classification of internal arc protection apply only to the test conditions specified in this standard. The instrument transformers may have different performance during an in-service internal arc fault. Refer to Annex D for more information regarding the interpretation of internal arc protection. The pertirrnance does not apply to any internal pressure rclief device (e.g., rupture disc) provided with the transformers.IEEE C57.13.5 pdf free download.