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

[w_tom <w_tom1@usa.net>]

   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.

  39 joules is grossly undersized surge protection.  Effective residential surge
protection starts at 1000  joules.  But MOVs are effective for direct strike
surge protection.  Unfortunately so many purchase undersized surge protection
that is not connected to earth ground, suffer damage, then assume nothing will
protect from the direct pole strike.  Such lightning strikes should never damage
electronics - as I have proven a number of times, and as professionals have
proven repeatedly since the 1930s.

"Michael J. Mahon" wrote:

> The so-called "surge protectors" that are widely sold (at least in the U.S.)
> based upon one to three MOVs shunted across the hot, neutral, and ground
> AC supply leads are not intended to be lightning arrestors.
>
> They will do nothing to protect the poor devil whose power pole is struck
> by lightning.  But, some distance away, thousands of people who might
> have experienced a relatively low energy thousand-volt spike as a result
> of the relatively more distant lightning disturbance, will find that their
> equipment will turn on and work, instead of having its power supply diodes
> blown.  The surge protectors are for the many, not for the few unfortunates
> whose problem is severe.
>
> In most parts of the U.S.--some parts of Florida excepted--this insurance
> is quite sufficient, since most people will never experience a lightning-
> induced or switching-transient-induced failure in their lifetimes.  Certainly
> this is true in places where thunderstorms are rare and power is reliable.