IEC 61000-5-5:1996

This part of 61000-5 defines how protective devices for conducted
disturbance proposed for HEMP protection shall be specified. It is
intended to be used for the harmonization of existing or future
specifications issued by protective device manufacturers,
electronic equipment manufacturers, administrations and other
ultimate buyers. Performance requirements shall be given in future
IEC documents.

This section covers protective devices currently being used for
protection against induced HEMP transients on signal and low
voltage power lines (nominal voltage up to 1 kV a.c.).

General information can be applied also to high voltage lines.
However, in these cases, the additional requirements for the
protection levels of existing lightning arresters (especially
gapless MO-arresters) are under consideration.