International Standards and Conformity Assessment for all electrical, electronic and related technologies

News release – 2009 Number 07

New IEC Standards+ deals with short-circuit currents in three-phase AC systems

S+ IEC 60909-3

 

Geneva, Switzerland, 2009-03-24IEC 60909-3 on short-circuit currents in three-phase AC systems is now available as a new IEC Standards+. It includes the new third edition of this important International Standard with an annexed Redline version that shows all changes from the previous edition.

 

Developed by IEC Technical Committee 73: Short-circuit currents, the third edition of IEC 60909-3, Short-circuit currents in three-phase AC systems - Part 3: Currents during two separate simultaneous line-to-earth short circuits and partial short-circuit currents flowing through earth, specifies procedures for calculation of the prospective short-circuit currents with an unbalanced short circuit in high-voltage three-phase a.c. systems operating at nominal frequency 50 Hz or 60 Hz.

 

The ability to withstand maximum short-circuit currents, including their thermal and mechanical effects, concern all electrical apparatus and equipment. Thus short circuit calculations are essential for the electrical manufacturing industry, industrial power plants and power utilities to ensure safe design of components and systems to prevent damage of equipment and interruptions of public electric supply systems. The safety of involved personnel and third parties is also at stake.

 

IEC Standards+ Redline help save both time and money since they have the advantage of providing a customer with an immediate and accurate means of identifying where the technical content of the Standard has evolved from the previous edition. In this way, important areas of technology or safety are clearly highlighted so that customers can make necessary changes to their procedures and equipment.

 

The IEC is the world’s leading organization that prepares and publishes International Standards for all electrical, electronic and related technologies and that manages global conformity assessment systems.

 

S+ IEC 60909-3, Short-circuit currents in three-phase AC systems - Part 3: Currents during two separate simultaneous line-to-earth short circuits and partial short-circuit currents flowing through earth