SC 121A

IEC 60947-6-1:2020 applies to transfer switching equipment (TSE), to be used in power systems for ensuring the continuity of the supply and allowing the energy management of the installation, by transferring a load between power supply sources, the rated voltage of which does not exceed 1 000 V AC or 1 500 V DC.

This third edition cancels and replaces the second edition published in 2005, and its Amendment 1:2013. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous edition:

– clarification of scope and object;

– clarification of terms and definitions;

– removal of unnecessary definitions;

– modification of characteristics;

– modification of utilization categories definitions;

– introduction of new markings requirements;

– addition of new requirements for clearances and creepage distances;

– addition of new requirements and tests for mechanical and electrical interlocks;

– clarification of transfer sequences;

– modification of requirements for rated short-time withstand currents;

– modification of new requirements for electromagnetic compatibility;

– clarification of performance requirements for CB type TSE, in alignment with requirements stated in IEC 60947-2;

– addition of new test sequence V: Critical load current performance of equipment with DC ratings.