[lug] Aging Surge Protectors

Wagner, Carl Carl.Wagner at Level3.com
Fri Aug 27 11:56:27 MDT 2004

The way I understand it, the cheap units use MOV (metal oxide varistors) that
clamp down if you exceed the design voltage.  Every time it clamps down a portion
of the MOV is destroyed (not really sure about this).  The amount that is destroyed
is proportional to the magnitude of the over-voltage and duration.  So shelf life
should not matter, just the number of hits and magnitude, will affect it.

As I said, this is how I understand it. I could be completely wrong though.

I have no idea how high end units deal with over-voltage.

You could probably do some google-ing to find more.


-----Original Message-----
From: lug-bounces at lug.boulder.co.us
[mailto:lug-bounces at lug.boulder.co.us]On Behalf Of Timothy Klein
Sent: Friday, August 27, 2004 11:46 AM
To: Boulder (Colorado) Linux Users Group -- General Mailing List
Subject: Re: [lug] Aging Surge Protectors

On Friday 27 August 2004 11:01, Gordon Golding wrote:
> This might come through twice - having trouble with email.
> I'm putting in some servers and client workstations - somebody just
> said that as surge protectors age, they lose their capacity to
> protect.
> Has anybody ever heard this?

This is true, from my reading.  Something in the unit is consumed with 
use (don't remember what).  Some high end designs try to tell you 
when they fail, some really high end models use a more permanent 
design (the kind that clicks like mad -- it bleeds off current with a 
capacitor.  The standard ones shunt to ground, which can actually 
damage modems).  Cheaper models work for a time, and then fail 

This is all from imperfect memory.

== Timothy Klein || teece at silverklein.net
== Vanity Page: http://tinyurl.com/vkhp
== ----------------------------------------
== Hello_World.c: 17 Errors, 31 Warnings...
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