OPERATION OF CABLE UNDER LIGHTNING IMPULSE CONDITION. 1

[kenyap]

May i know where can i get more information about the operation of cable under the lightning impulse condition? Is there any specific sites that anyone had come across about the numerical analysis of cable.

 

[busbar]

MOV surge arresters are used in some areas up to 765kV, and on solid-dielectric cables up to at least 138kV. You may be able obtain useful information from their suppliers.

 

[arrester]

May i know where can i get more information about lightning arrester?

 

[redtrumpet]

- search for "lightning arrester" on internet
- contact local electrical distributors
- talk to electrical power engineering profs at nearest university
- contact major electrical equipment manufacturers
- contact IEEE
- contact IEC

After you have done all of the above, if you still have a specific question about lightning arresters, come back to this forum.

 

[JohnW]

A document that I have found very informative with reguard to how to protect circuits is ANSI/IEEE C62.41-1991 (ISBN 1-55937-130-7). It does not tell you about devices but rather the energy levels and test methods. This allows you to get a better understanding of what impulses will find their way into the circuits. Then you can pick surge protectors.

When choosing surge protectors be aware of the response times. Varistors, and spark gaps are not fast enough to protect most semiconductors by themselves. Zener or avalance devices are faster but may not protect against fast transients with < 10 ns rise time. The zener may itself be damaged. For these fast transients a small inductor and/or capacitor may be required - to slow the rise time - before the surge protector.