MT 37 - TC 17/SC 17A/MT 37

IEC 62271-104:2020 is applicable to three-pole alternating current switches for rated voltages higher than 52 kV, having making and breaking current ratings, for indoor and outdoor installations, and for rated frequencies up to and including 60 Hz.
This third edition replaces and cancels the second edition published in 2015. It constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
- new numbering, following IEC 62271-1:2017.

IEC 62271-104:2015 is applicable to three-pole alternating current switches for rated voltages higher than 52 kV, having making and breaking current ratings, for indoor and outdoor installations, and for rated frequencies up to and including 60 Hz. This standard is also applicable to the operating devices of these switches and to their auxiliary equipment. This second edition replaces and cancels the first edition published in 2009 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- the title was changed such that the voltage range now is >52 kV instead of ≥52 kV;
- the references have been updated;
- the comments in 17A/1063/RVC have been addressed.
This publication is to be read in conjunction with IEC 62271-1:2007, IEC 62271-100:2008, IEC 62271-102:2001  and IEC 62271-110:2012.

IEC 62271-104:2009 applies to three-pole alternating current switches for rated voltages 52 kV and above, having making and breaking current ratings, for indoor and outdoor installations, and for rated frequencies up to and including 60 Hz. This standard is also applicable to the operating devices of these switches and to their auxiliary equipment. The main object of this standard is to establish requirements for switches used in transmission and distribution systems. General-purpose switches for this application are designed to comply with the following service applications:
- carrying rated normal current continuously;
- carrying short-circuit currents for a specified time;
- switching of mainly active loads;
- switching of no-load transformers;
- switching of the charging current of unloaded cables, overhead lines or busbars;
- switching of closed-loop circuits;
- making short-circuit currents.
A further object of this standard is to establish requirements for limited-purpose and special- purpose switches used in transmission and distribution systems. Limited-purpose switches shall comply with one or more of the service applications indicated above. Special-purpose switches may comply with one or more of the service applications indicated above and, in addition, shall be suitable for one or more of the following applications:
- switching single capacitor banks;
- switching back-to-back capacitor banks;
- switching shunt reactors including secondary or tertiary reactors switched from the primary side of the transformer;
- applications requiring an increased number of operating cycles;
- switching under earth fault conditions in non-effectively earthed neutral systems.
This standard cancels and replaces IEC 60265-2:1988. The major changes with respect to IEC 60265-2 are as follows:
- alignment with IEC 62271-1 and IEC 62271-100;
- requirements for capacitive current switching aligned with those in IEC 62271-100: classes C1 and C2 are introduced.
This publication is to be read in conjunction with IEC 62271-1:2007, IEC 62271-100:2008, IEC 62271-102:2001  and IEC 62271-110:2005.