: The standard now uses the "charge classification" system (e.g., Qrscap Q sub r s end-sub Qthcap Q sub t h end-sub
Here is some sample text written with some minor format:
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
The 2018 update replaced the previous 2013 edition and introduced significant technical revisions to align with the new surge arrester classification first established in IEC 60099-4:2014 . Major changes include:
If you ignore the "UPD" and stick to an old PDF, you risk designing a protection scheme that is "code compliant" but practically inadequate for a modern, dynamic grid.
