MT 3 - TC 81/MT 3

IEC 62305-4:2024 provides requirements for the design, installation, inspection, maintenance, and testing of surge protection measures (SPM) for electrical and electronic systems to reduce the risk of permanent failures due to lightning electromagnetic impulse (LEMP) within a structure.
This third edition cancels and replaces the second edition published in 2010. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) addition of new informative Annex E and Annex F on the determination of current sharing using modelling and current sharing in PV installations respectively;
b) addition of a new informative Annex G on methods of testing of system level behaviour;
c) addition of a new informative Annex H on induced voltages in SPD-protected installations.

Provides methods for the evaluation of the effectiveness of shielding measures against LEMP for structures with information equipment such as electronic systems in case of direct and nearby lightning strikes. In addition it provides rules for bonding measures inside structures and for earthing methods relating to LEMP.

Gives guidelines for protection of information technology equipment (ITE) against lightning magnetic impulse (LEMP) effects in existing structures and includes methods suitable for new structures. A checklist helps to address specific points and to select the most economical measures for the hardening of equipment against LEMP. The checklist facilitates risk analysis and selection of the most suitable counter measures.

Gives information for the design, installation, inspection, maintenance and testing of an effective lighning protection system for information systems in or on a structure.