MT 49 - TC 17/SC 17A/MT 49

IEC 62271-102:2018 applies to alternating current disconnectors and earthing switches, designed for indoor and outdoor installations for nominal voltages above 1 000 V and for service frequencies up to and including 60 Hz.
This second edition cancels and replaces the first edition published in 2001, Amendment 1:2011 and Amendment 2:2013. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:  
new numbering according to IEC 17/1025/RQ to harmonize with ISO/IEC Directives, Part 2, and IEEE Std. C37.100.1;
clause numbering has been aligned with IEC 62271-1:2017;
the Scope has been extended to cover all indoor and outdoor installations. Consideration of switching devices having disconnecting and/or earthing switch functionalities, apart from other functions, are also covered by this document;
ratings have been moved from Annexes B, C and E to Clause 5; the order of the subclauses now corresponds to the order of subclauses in Clause 7;
new rating values for bus-transfer current and bus-transfer voltage have been assigned;
new class of mechanical endurance for earthing switches has been added (M1);
subclause "Rated values of electrical endurance for earthing switches" is now called "Classification of earthing switches for short-circuit making capability";
new subclause with ratings for ice-coating has been added;
new subclause with classification of bus-charging switching capability has been added;
new withstand requirements for interlocking devices have been added;
the way to comply with the requirements of the isolating distance of disconnectors has been modified;
design and construction requirements for position-indicating devices have been modified, aligning the requirements for position indication and signalling;
the value of the operating force has been changed;
the test procedures and validation criteria have been revised and modified where necessary;
requirements for applied voltage during single-phase test on non-simultaneous closing earthing switches have been changed;
non-verifiable requirements have been deleted;
a new subclause has been added for testing mechanical interlocking devices;
the high- and low-temperature test is mandatory if the temperature limits for the service conditions of the apparatus (defined by the manufacturer) are above +40 °C or below −5 °C, and a more detailed testing procedure is given;
the testing procedure to verify the proper functioning of the position-indicating device allows a more practicable testing for every technology used;
a new Annex B has been added with title: "Current-switching capability required of disconnectors and earthing switches";
a new Annex C has been added with title: "Tolerances on test quantities for type tests";
a new Annex E has been added with title: "Extension of validity of type tests".