Re: System Saver IIgs -- ID of burned part?-- line protection

[mjmahon@aol.com (Michael J. Mahon)]

w_tom replied:

>   I protected one half of a house with what I now know to be a grossly
>undersized MOV surge protector - 39 joules.  When lightning directly struck
>the
>pole, everything - yes, everything electronics on the unprotected side was
>destroyed.  Nothing - then or weeks later - was damaged on the protected
>side.
>However a month later, my friend called with no power on the protected side.
>The
>grossly undersized MOV shunted so much power to earth ground through the
>meter,
>that that side of a partially damaged meter completely failed when he turned
>on
>his air conditioner.
>
>  Yes, even that grossly undersized MOV provided effective surge protection.
>But
>it had an advantage.  It was only 2 feet to an earth ground rod in conductive
>soil.  Of course and obviously, a surge protector is only as good as its
>earth
>ground.  This earth ground was both short and conductive meaning that even a
>grossly undersized MOV was sufficient protection - albeit only for one surge.

Yes, and in this case the MOV was functionally equivalent to a spark gap!

-michael

 Email:  mjmahon@aol.com
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