This part of IEC 62271 applies to the procedures for handling of gases for insulation and/or switching during installation, commissioning, repair, overhaul, normal and abnormal operations and disposal at the end-of-life of electric power equipment.

These procedures are regarded as minimum requirements to ensure the reliability of electric power equipment, the safety of personnel working with these gases and to minimize the impact on the environment. Additional requirements could be given or specified in the operating instruction manual of the manufacturer.

For each gas, which is known to be used in electric power equipment at the date of the publication of this document, a separate annex describes specifications, handling procedures, safety measures, etc. For gases not covered by these annexes the electric power equipment manufacturer should provide the information needed, following the structure of these annexes. Such gases should also be described in a next edition or in amendments to this edition.

NOTE 1 For the use of this document, high-voltage (HV) is defined as the rated voltage above 1 000 V. However, the term medium-voltage (MV) is commonly used for distribution systems with voltages above 1 kV and generally applied up to and including 52 kV.

NOTE 2 Throughout this document, the term "pressure" stands for "absolute pressure".

NOTE 3 In this document, percentages of gaseous components, contaminants and by-products, are always percentages per volume, measured at 20 °C, if not otherwise indicated.

NOTE 4 Reference is also made to CIGRE Brochure 802 [1] 1.

NOTE 5 For further details on gases, e.g. ecotoxicology, also refer to the chemical database of the European Chemicals Agency, ECHA (www.echa.europa.eu), which takes the actual tonnage band into consideration.

NOTE 6 If gases for insulation and/or switching are regulated, their designation and regulation origin can be found in the IEC 62474 database (available at https://std.iec.ch/iec62474 [26]).

NOTE 7 When reference to circuit-breakers is made, only gas circuit-breakers are of interest. When vacuum circuitbreakers are of interest, they are explicitly mentioned.