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 withIEC 61534-1:2011.