TEN350 The waveform that hijacked the IEC lightning standards
IEC lightning protection standards mortally infected by 10/350 virus
The 10/350 waveform pervades every major aspect of IEC international lightning protection standards.
From setting lightning parameters to computing magnetic fields; from determining SPD tests to assessing potential risk; from calculating a rolling sphere radius to choosing & coordinating SPDs; from establishing LPZs (lightning protection zones) to specifying lightning protection levels (LPL) -- the 10/350 waveform infects every one of these processes.
Electrical and Electronic systems within structures
After announcing the 10/350 waveform to be the "primary source of electromagnetic harm" (thus requiring spark gaps), the standard spends over 1/3 of its pages trying to figure out how to coordinate those spark gaps with more effective surge protection. Read about it.
Low Voltage Surge Protective Devices-Part 11: Requirements
and test methods
While cancelling its predecessor, IEC 61643-1, it nevertheless managed to retain all its 10/350 flaws. SC37A apparently tried to avoid the stigma of the 10/350 waveform in this standard by mentioning it only once. But this standard remains badly infestated. Read how.
Green energy protection painted & tainted
The protection of alternative energy installations has not avoided a shellacking by the 10/350 brush. IEC 61400 Wind Generator Systems – Part 24 Lightning Protection was published in 2010 by IEC TC/SC 88. The technical committee probably had no choice but to "harmonize" with 62305's lightning parameters. But they might have realized that the "rolling sphere method" and "lightning protection zones" have no applicability whatsoever to wind turbines. Sadly those wishing to implement 61400-24 now must now bear the burden of the 10/350 waveform and its consequences. Because lightning takes such a dreadful toll on wind turbines each year, the members of TC/SC 88 would be well advised to review this aspect of the standard.
IEC and Ethics
Click here to view the genesis and development of the 10/350 waveform and Class I Test. Some would say it's not a very pretty picture. Such things don't just "happen." They are caused.