Posted by Sarah on July 27, 2007, 2:06 am
Hello, we have new, very expensive computer, and many lightening
storms around here. I searched on the internet a bit and discovered
there are two kinds of surge protectors...one that sends the current
to ground, and one that absorbs it and lets it dissipate slowly. Seems
like the Isobar and the Zero Surge are good examples of the two kinds.
Since the Isobar has lights to indicate if it's working I am not
concerned about it degrading over time. Which one of these protectors
really protects the best? Or should I look at something else?
Thanks....
Sarah
Posted by philkryder on July 27, 2007, 2:26 am
> Hello, we have new, very expensive computer, and many lightening
> storms around here. I searched on the internet a bit and discovered
> there are two kinds of surge protectors...one that sends the current
> to ground, and one that absorbs it and lets it dissipate slowly. Seems
> like the Isobar and the Zero Surge are good examples of the two kinds.
> Since the Isobar has lights to indicate if it's working I am not
> concerned about it degrading over time. Which one of these protectors
> really protects the best? Or should I look at something else?
> Thanks....
> Sarah
You might consider one of the APC UPS products that provides surge
protection, low voltage protection, over voltage protection and of
course, UPS.
If the computer is as expensive as you say, then maybe the data and
the uptime can be justified.
APC Smart-UPS XL 750VA
http://www.apc.com/tools/ups_selector/index.cfm
Amazon has them as other places for under $450.
Posted by w_tom on July 29, 2007, 9:02 pm
> You might consider one of the APC UPS products that provides surge
> protection, low voltage protection, over voltage protection and of
> course, UPS.
> If the computer is as expensive as you say, then maybe the data and
> the uptime can be justified.
Where does APC cite each type of surge and claim to protect from
that surge? Why do they not make that claim? Get its numeric specs -
not a color glossy advertisment.
So how many joules provides protection? Why is that protector
circuit no better than one selling in a grocery store for $6? No
mystery. Review and post spec numbers.
It contains joules to claim surge protection. But it does not say
what it protects from. Its number is near zero joules - near zero
protection. Two immediately suspicious facts. But it does claim to
protect from something. Too few joules to protect from a type of
surge that typically does not damage electronics? But enough joules
(greater than zero) to be called a protector. Grossly undersized; but
it is a protector.
It has no dedicated earthing wire. Therefore how does it protect
from surges. Does it somehow stop or absorb what three miles of sky
could not? But again, even the manufacturer will not claim to
protect from surges that typically damage electronics.
Why does anyone recommend a UPS for surge protection when it really
only protects from a surge that typically does no overwhelm protection
already inside computers and other appliances? Why do responsible
(high reliability) facilities not use this type of UPS for
protection? Instead they install a building wide UPS with a short
connection to the building's single point earth ground. Notice the
difference. UPS that actually claims such protection also has that
dedicated earthing wire.
How many joules does that APC UPS contain? Why so few?
Another noted that an indicator lamp reports a protector as good.
Not true. Indicator can report a failure that is not acceptable.
Indicator does not report a protectors degraded - as was posted.
Indicator reports that a surge has overwhelmed the protector.
Protector failed to provide effective protection. Surge that did not
even harm an adjacent appliance did create an unacceptable
catastrophic protectors failure. This can happen when the protector
is grossly undersized.
Properly sized protectors routinely shunt every surge and remain
functional. Properly sized means the human should never even know a
surge existed.
A thermal fuse blows so that the undersized protector does not harm
humans. However sometimes that fuse - the safety backup - is not
sufficient especially when a protector is grossly undersized and in a
dangerous location:
http://www.hanford.gov/rl/?pageU6&parentU4
http://www.westwhitelandfire.com/Articles/Surge%20Protectors.pdf
http://www.ddxg.net/old/surge_protectors.htm
http://www.zerosurge.com/HTML/movs.html
How serious is this human safety problem created by protectors with
too few joules and located where fire is a threat? Gaston County Fire
Marshall reports:
http://tinyurl.com/3x73ol or
http://www.esdjournal.com/techpapr/Pharr/INVESTIGATING%20SURGE%20SUPPRESSOR%20FIRES.doc
Posted by Solar Flare on July 29, 2007, 11:01 pm
Protectors do not shunt "surges", but rather "spikes". A surge takes
complex electronics to circumvent (UPS usually) and no MOV or other
simple electronics component can stop a high voltage surge that lasts
for several cycles or seconds.
>> You might consider one of the APC UPS products that provides surge
>> protection, low voltage protection, over voltage protection and of
>> course, UPS.
>>
>> If the computer is as expensive as you say, then maybe the data and
>> the uptime can be justified.
> Where does APC cite each type of surge and claim to protect from
> that surge? Why do they not make that claim? Get its numeric
> specs -
> not a color glossy advertisment.
> So how many joules provides protection? Why is that protector
> circuit no better than one selling in a grocery store for $6? No
> mystery. Review and post spec numbers.
> It contains joules to claim surge protection. But it does not say
> what it protects from. Its number is near zero joules - near zero
> protection. Two immediately suspicious facts. But it does claim to
> protect from something. Too few joules to protect from a type of
> surge that typically does not damage electronics? But enough
> joules
> (greater than zero) to be called a protector. Grossly undersized;
> but
> it is a protector.
> It has no dedicated earthing wire. Therefore how does it protect
> from surges. Does it somehow stop or absorb what three miles of sky
> could not? But again, even the manufacturer will not claim to
> protect from surges that typically damage electronics.
> Why does anyone recommend a UPS for surge protection when it really
> only protects from a surge that typically does no overwhelm
> protection
> already inside computers and other appliances? Why do responsible
> (high reliability) facilities not use this type of UPS for
> protection? Instead they install a building wide UPS with a short
> connection to the building's single point earth ground. Notice the
> difference. UPS that actually claims such protection also has that
> dedicated earthing wire.
> How many joules does that APC UPS contain? Why so few?
> Another noted that an indicator lamp reports a protector as good.
> Not true. Indicator can report a failure that is not acceptable.
> Indicator does not report a protectors degraded - as was posted.
> Indicator reports that a surge has overwhelmed the protector.
> Protector failed to provide effective protection. Surge that did
> not
> even harm an adjacent appliance did create an unacceptable
> catastrophic protectors failure. This can happen when the protector
> is grossly undersized.
> Properly sized protectors routinely shunt every surge and remain
> functional. Properly sized means the human should never even know a
> surge existed.
> A thermal fuse blows so that the undersized protector does not harm
> humans. However sometimes that fuse - the safety backup - is not
> sufficient especially when a protector is grossly undersized and in
> a
> dangerous location:
> http://www.hanford.gov/rl/?pageU6&parentU4
> http://www.westwhitelandfire.com/Articles/Surge%20Protectors.pdf
> http://www.ddxg.net/old/surge_protectors.htm
> http://www.zerosurge.com/HTML/movs.html
> How serious is this human safety problem created by protectors with
> too few joules and located where fire is a threat? Gaston County
> Fire
> Marshall reports:
> http://tinyurl.com/3x73ol or
>
http://www.esdjournal.com/techpapr/Pharr/INVESTIGATING%20SURGE%20SUPPRESSOR%20FIRES.doc
>
Posted by w_tom on July 31, 2007, 12:52 am
> Protectors do not shunt "surges", but rather "spikes". A surge takes
> complex electronics to circumvent (UPS usually) and no MOV or other
> simple electronics component can stop a high voltage surge that lasts
> for several cycles or seconds.
Nothing stops the typically destructive high voltage surge. The
typically destructive surge seeks earth ground. Either it is shunted
to earth, or it enters a building to find earth ground, destructively,
via household appliances.
What are these high voltages that last for several cycles or
seconds? First these are not the surges that typically damage
electronics. Second, those are not surges that Tripplite, Zerosurge
device, or typical UPS claims to protect from. Third, 120 VAC
electronics contains internal protection for various surges up to 600
volts. Computer power supplies are even more robust. Internal
protection that makes protection in those claims irrelevant. Internal
protection that may be overwhelmed if a typically destructive surge is
not earthed before entering a building.
As Neon John notes, normal mode surges created by switching are also
made irrelevant by protection inside appliances; typically are not
destructive. Surges created by utility switching become common mode
- seek earth ground either destructively or are earthed where wire
enters the building.
As Neon John also notes, the earthing must be low impedance. That
means even longer wire would have too much impedance. Same reason
why the earthing connection is typically 'less than 10 feet', no sharp
bends, etc. Just more things to make earthing sufficiently
conductive. Just another reason why the 'whole house' protector or a
direct wire is connected to each incoming utility wire at a common
point - the service entrance. So that a surge is earthed before it
can even enter the building.
Typically destructive surges are made irrelevant (do not overwhelm
protection already inside appliances) if earthed. Most common source
of such surges? Lightning. Lightning is why earthed protectors are
sufficiently sized OR why utility wire (ie cable) connects directly to
earth. Same solution is routinely installed in every high
reliability facility. Same solution is missing in homes where the
homeowner does not take responsibility to meet and exceed earthing as
required by National Electrical Code and to install a 'whole house'
protector where necessary.
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> storms around here. I searched on the internet a bit and discovered
> there are two kinds of surge protectors...one that sends the current
> to ground, and one that absorbs it and lets it dissipate slowly. Seems
> like the Isobar and the Zero Surge are good examples of the two kinds.
> Since the Isobar has lights to indicate if it's working I am not
> concerned about it degrading over time. Which one of these protectors
> really protects the best? Or should I look at something else?
> Thanks....
> Sarah