INTERNATIONAL STANDARDS

Because of the diversity and importance of transients, standards organizations have created specifications for testing the effects of overvoltages on equipment.

The phenomena were first characterized and a series of standardized waves created (1.2/50µs voltage wave and 8/20µs and 10/350µs current waveforms), then a number of standards defining surge arrester performance were issued, among them :

Surge Protectors for Low-Voltage installations:

• NF EN 61643-11 (France)
• VDE 0675-6-11 (Germany)
• EN 61643-11 (Europe)
• UL1449 (USA)
• IEC 61643-11 (International)

Surge Protectors for Telecom equipment:

• IEC 61643-21 (International)
• ITU-T recommendations K11, K12, K17, K20, K21, K36 (International)
• UL 497 A/B (USA)