Method to simulate lightening into the AC line

Sep 14, 2005 3 Replies

Hi All,



To simulate a near strike, I have a power supply which will supply 10KV but at low current, I use this supply to charge a 0.3uF cap and this gives me about 15J.



The charged cap is then discharged into either the chassis metal, the Line, or the neutral/green wire where the neutral/green are shorted together.



Power is applied to the unit as it normally is on, inside the house,



24/7

The question is 15J discharge from the cap high enough or must I go higher?



Thanks!



pdrunen



A reasonable simulation might possibly need to mimic the rise and fall times of the pulse - it depends why you are doing it. Near is of course a relative word. I'm sure there must be some literature published on this.

It depends on the environment that you are trying so simulate.

Energy delivered to LV long branch circuits and outlets (cat2) in testing is typically less than 1J. (6KV 200A .5uSec 100KHz)

The same test on short branch and feeder circuits (cat3) is more than double this, with additional 20uSec impulse waveforms potentially delivering 40J into a low impedance circuit.

You might check for articles by Franois Martzloff, refering to IEEE Std C62.41 or IEC Basic Standard 77B, which both cover the environmental classification and testing of circuits for transient and surge susceptibility.

These used to be available from NIST..

formatting link

RL

I read in sci.electronics.design that legg wrote (in ) about 'Method to simulate lightening into the AC line', on Wed, 14 Sep 2005:

There ain't no sich critter as that second one; 77B is a committee, not a standard. Look in the IEC 61000-4-xx series.

Regards, John Woodgate, OOO - Own Opinions Only. If everything has been designed, a god designed evolution by natural selection. http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

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