IEC 61534-1:2011 specifies general requirements and tests for powertrack (PT) systems with a rated voltage not exceeding 277 V a.c. single phase, or 480 V a.c. two or three phase 50 Hz/60 Hz with a rated current not exceeding 63 A. These systems are used for distributing electricity in household, commercial and industrial premises. This second edition cancels and replaces the first edition published in 2003 and constitutes a technical revision. The main changes from the previous edition are as follows: - updated normative references (Clause 2); - changes to the number of samples to be tested (Subclause 5.3); - inclusion of a short circuit test (New Clause 18); - changes to external influences (Clause 21).