IEC 61534-21:2014 specifies the particular requirements and tests for PT systems intended for mounting on walls and/or ceiling. They may be installed flush or semi-flush, surface mounted, suspended or spaced away from the surface using fixing devices. This second edition cancels and replaces the first edition published in 2006 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - Clauses 18 to 22 have been adapted to IEC 61534-1:2011 and include short-circuit test requirements; - Additional classification, terms and requirements for wall powertrack (PT) systems mounted at the skirting level (close to the floor) position. This publication is to be read in conjunction with IEC 61534-1:2011.