The IEC 60099-5 standard is the primary international guide for the selection and application of surge arresters in three-phase systems with voltages exceeding 1 kV. IEC Webstore The latest official edition is IEC 60099-5:2018 (Edition 3.0) IEC Webstore Official Purchase and Access Links

Sizing a surge arrester requires balancing normal grid operating limits against transient extreme voltages.

rating represents the maximum power-frequency voltage the device can safely handle indefinitely. It must be higher than the highest expected system voltage ( ) under normal operating conditions. Step 2: Temporary Overvoltage (TOV) Evaluation

Simplified mathematical assumptions based on line impedance.

: Available digitally via the IEC Webstore , the ANSI Webstore , and regional standard bodies like BSI Knowledge . Preceding Versions : Supersedes IEC 60099-5:2013. What is covered in IEC 60099-5?

The transition from the second edition (2013) to the third edition (2018) brought major structural updates to align with the established in the manufacturing standards. Technical Area Older Editions (Pre-2018) Modern 2018 Standard Framework Arrester Classification Categorized by Line Discharge Classes (Classes 1 to 5). Categorized by thermal charge ( Qthcap Q sub t h end-sub ) and repetitive charge ( Qrscap Q sub r s end-sub Energy Calculations

Complete Guide to IEC 60099-5: Surge Arrester Selection and Application Recommendations

You can purchase the latest IEC 60099-5:2018 or the Redline Version (RLV), which highlights changes from previous editions.

It applies to several types of arresters:

Selection methods aligned with the 2014 revisions in IEC 60099-4. Charge Classification:

in three-phase systems with nominal voltages above 1 kV. It covers gapless metal-oxide arresters, gapped designs, and externally gapped line arresters (EGLA). iTeh Standards Official PDF Links and Access

Older versions sorted high-voltage arresters by generic Line Discharge Classes (Classes 1 through 5). The updated standard uses a physical measurement system based on and thermal charge transfer capability ( Qthcap Q sub t h end-sub ) . Enhanced Energy and Stress Estimation