New Arrester Classifications and Energy Handling Requirements IEC 60099-4 Ed 3.0 2014
Arrester class | Station | Distribution | ||||
Designation and Duty Level | SH Heavy | SM Medium | SL Light | DH Heavy | DM Medium | DL Light |
Nominal discharge current | 20 kA | 10 kA | 10 kA | 10 kA | 5 kA | 2,5 kA |
Switching impulse discharge current | 2 kA | 1 kA | 0,5 kA | -- | -- | -- |
Qrs (Coulombs) | ≥ 2.4 | ≥ 1.6 | ≥ 1.1 | ≥ 0.4 | ≥ 0.2 | ≥ 0.1 |
Wth (kJ/kV) | ≥ 10 | ≥ 7 | ≥ 4 | -- | -- | -- |
Qth (Coulombs) | -- | -- | -- | ≥ 1.1 | ≥ 0.7 | ≥ 0.45 |
Old Classification | Class 4/5 | Class 3 | Class 2 | Class 1 | Class 1 / 5kA | Class 1 / 2.5kA |