Explosion for the Lightning Arrestor

Without any data about line configuration, voltage rating, operating conditions, what might have changed, how it failed, etc., etc., it is impossible to give more than the obvious answers; i.e., transient switching overvoltage, improperly sized arrestor, severely contaminated arrestor.

The obvious reason is that the circuit breaker closed. Duh.

The lightning arrestor died instead of the more expensive equipment. I do not see a problem here.

Now if lightning did not take out this lightning arrester and none of your engineers are willing to explain how their design was either miswired, used faulty components or a fault in the design itself was the root cause then you will have to hire a licensed engineer to investigate.

Save and document all failed components for your in house or independent investigator.

Sounds to me like that arrestor "took one for the team" ie it did its job.

More information please.

Also clarify that when you say the CB is "closed" it is in the ON position (the terms open and close as relating to switches can transpose with language, eg opening the light switch means turning on the light here)

May due to defective unit of lightning arrestor . Whether you performed testing on lightning arrestor before installation .

Whether there is a chance for corona discharge ?

Lightning arrestors go bang sometimes. When they do it's a good thing. Unless it was installed too close to other equipment without segregation and collateral damage has occurred. An arrestor is a darn sight less costly then what they normally protect.

How do you propose testing the arrestor without destroying it or accelerating the onset of a smoke release episode once in service?

Corona discharge.....normally associated with high energy events. Normal. Clutching at straws on that one.

The most likely reason is the breaker closed in on an already failed arrester. Arresters typically fail in a short circuit. Although you didn't mention the reason the breaker was open, it may have opened to clear the failed arrester.

Dear all

thanks for all

Can anyone tell me why voltages increase when the breaker is closed and what level rise if the breaker in the 132kv network

Regardes

Your engineer should be able to tell you why closing a breaker will change the voltage. Your engineer should know what is connected on either side of that breaker. We do not know this, so we cannot help you.

Just don't open the other breaker that I'm pointing toward. I'm not done yet. You'll have to answer to my wife if you do.

I'll venture a guess and say that plasma had something to do with the explosion, if you want to get down to brass tacks.

You want to know why voltage increases when you close the input to a circuit? Are you serious? Is there another way you can configure your question in order to ensure you get an accurate answer?

One of the possibilities is that there was a mongoose crawling past the lightning arrester when the breaker was closed.

Or it might have been a snake. It's a bit difficult to see the charred remains of whatever-it-was from here.