IEC 61439-2:2020 defines the specific requirements for the power switchgear and controlgear assembly (abbreviated "PSC-assembly" throughout this document see 3.1.101) as follows:
- assemblies for which the rated voltage does not exceed 1 000 V AC or 1 500 V DC;
- assemblies designed for a nominal frequency of the incoming supply or supplies not exceeding 1 000 Hz;
NOTE 1 Frequencies above 1 kHz are considered as high frequencies, see also IEC 60664-1:2007, 5.3.3.2.5 to take into account additional constraints to insulation coordination.
- assemblies intended for indoor and outdoor applications;
- stationary or movable assemblies with or without enclosures;
- assemblies intended for use in connection with the generation, transmission, distribution and conversion of electrical energy, and for the control of equipment consuming electrical energy and for associated data processing;
- assemblies designed for use under special service conditions, for example in ships and in rail vehicles, provided that the other relevant specific requirements are complied with;
NOTE 2 Supplementary requirements for assemblies in ships are covered by IEC 60092-302-2.
This third edition cancels and replaces the second edition published in 2011. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) addition of Annexes DD, EE and FF for assemblies for use in photovoltaic installation;
b) clarification of the requirements for forms of internal separation and the addition of the requirement, when the form of separation is higher than 1, all parts within the functional unit compartment that remain live when the functional unit is switched off shall be protected to at least IPXXB;
c) alignment with the structure of IEC 61439-1:2020;
d) addition of temperature-rise verification for; (i) temperature-rise verification of assemblies with natural cooling and circuits rated above 1 600 A by a combination of comparison with a reference design and calculation, and; (ii) temperature-rise verification of assemblies with active cooling and rated currents up to 1 600 A;
e) consideration of IP with active cooling.