Instead of the old "Class 1 to 5" system, arresters are now classified by their thermal energy dissipation and repetitive charge transfer capability ( Qrscap Q sub r s end-sub
Selection workflows now place heavier emphasis on maximum residual voltage as the primary parameter for insulation coordination.
Annex D was updated to include modern service monitoring techniques, such as leakage current measurement with harmonic compensation. iec 600995 pdf upd
This guide outlines the critical updates in the standard, the transition from older classifications, and how to access the latest documentation for compliant system design.
These new sections provide direct comparisons and mathematical formulas to convert old line discharge classes into modern charge classifications. Instead of the old "Class 1 to 5"
Including series and parallel gapped arresters rated ≤is less than or equal to 52 kV per IEC 60099-6 .
The standard, titled "Surge arresters – Part 5: Selection and application recommendations," is the definitive global guide for engineers designing and maintaining high-voltage power systems. As of early 2026, the current active version is IEC 60099-5:2018 (Edition 3.0) . As of early 2026, the current active version
The IEC 60099-5 standard provides non-mandatory but highly recommended guidelines for the selection of surge arresters in three-phase systems with nominal voltages . It covers several specific arrester technologies: Gapless Metal-Oxide (MO) Arresters: Defined in IEC 60099-4 .