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From: smh@alux2.ATT.COM (S. Henning)
Newsgroups: misc.consumers,comp.misc,sci.electronics
Subject: Re: Surge protector advice needed
Keywords: surge protectors
Message-ID: <288@alux2.ATT.COM>
Date: 29 Mar 89 13:46:58 GMT
References: <1099@wpg.com>
Organization: AT&T Bell Laboratories
Lines: 51

> In article <1099@wpg.com>, linda@wpg.com (Linda Guidry) writes:
> > 
> > One of my non-net neighbors has had some *serious* surge problems...
> > 
> > Given the fact that there are a jillion different surge protectors
> > on the market these days, she'd really appreciate some suggestions 
> > from electrical engineers and/or knowledgeable consumers concerning 
> > the names of the better brands.
> > 
> > Also, what features should my friend be looking for to protect 
> > computers and laser printers?   


I installed a primary surge protector in my breaker box.  These are
available at most electrical supply houses.  They provide gas tube
protection at the point of entry.  Gas tubes can absorb an enormous
amount of energy but are not as fast as zener diodes.  At the point
of use another good protector is desirable.  It usually has a surge
absorber made from either a gas tube or a zinc oxide MOV and also
an electronic surge barrier formed from inductors, capacitors
and zener diodes.  This 2 level surge protection is the only level
that will survive a close lightning strike.  My house is full of
electronic goodies and before we installed the above system, we
were sending things back to the manufacturer to be repaired all
the time.  Now we have no problems.

Don't forget that surges come in the phone line and cause problems.
The phone company installs primary protectors where the wires enter
your home.  These are designed to keep the voltage on the phone line from
rising above 600 to 1000 volts depending upon the model, and the number
of times that it has been zapped.  I found out the hard way that this is
not good enough to protect some modems.  Now I use a secondary lightning
protector on all lines with modems.  These are available from such places
as Inmac for $59.  I have had two of the Inmac protectors smoked (burned
up) by lightning strikes but they saved the modem in each case.  If some
one knows of a better protector I would be interested.  I am on the end
of a long telephone line that runs through a valley.  Whenever a storm
hits the valley, our phone rings on every strike.  However, only when
we get a strike in our yard do we get the protectors smoked.

As to brands, stick to ones backed up by you local computer store.
The world is full of inexpensive clones that are not UL rated.
Avoid these.  In addition to UL rating, look for the IEEE 587
rating.  This pertains to the effectiveness as a surge protector
while the UL rating is for fire insurance purposes.  The best
point of use protectors meet IEEE 587 class A & B.  The gas tube
protectors that fit in the breaker box only have a UL rating.

Cheers,
Steve Henning, AT&T Bell Labs, Reading, PA           UUCP: att!alux2!smh
****                    Lang May Your Lum Reek                      ****