Surge protectors - na
barry martin
D > I saw several of those lower end APCs while comparison shopping today
D > - in Walmart, Staples, etc. $60 seems reasonable. I really don't need
D > a lot of backup time. However, the unit was listed as a 200 watt unit.
D > My system has a 300 watt power supply. Will that be a problem? I
Two different things. Think of the wattages like your stereo. The
amp puts out x-number of watts to your speakers but consumes y-number
of watts. For the UPS you are concerned with the 'y' number. (This
number will be or can be derived from the specification data in the
manual or from the model info sticker on the back. 1 amp is
approximately 120 watts.
D > actually don't care about the UPS function. The only thing I'm
D > interested in protecting is the computer itself and am looking for the
D > most frugal solution short of unplugging the computer whenever I'm not
D > using it.
D >
D > I think I'm still missing the whole Joule thing (aside from it being a
D > marketing ploy to get a higher-looking rating) when it comes to
D > protecting actual computer components. Are these ratings something I
D > need to be aware of if I don't care about minutes of backup power?
A higher Joule figure is better, but also relates to a duration
figure. 1,000,000 Joules at 500 milliseconds is better than 1,000,000
Joules at 200 ms.
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barry martin
D > I have the misfortune of renting a place that has no electrical
D > ground. Searching through the google/deja.com newsgroup archive, there
D > seems to be some controversy over whether or not a place without an
D > electrical ground will benefit from a surge protector. Anyone got a
D > definitive answer on that?
From what I have read if the ground isn't there the surge protector
offers little if any protection -- where is the shunted voltage to go?
(I've also read where the distance the this shunted voltage has to
travel to reach the ground makes a difference. The ground wire is a
path to the actual ground, not the ground itself.)
As you have no ground I would suggest adding one. Could rewire the
place (get landlord's permission!).... OK, that was a joke. What I
did when I had a three-prong outlet that was for some reason not
grounded at my apartment was run a length of 18g wire from the problem
outlet (took off the cover, attached my wire to the mounting screw).
Took a nibbling tool to notch the cover for the wire. Ran the wire
down the wall, under the baseboard, to the cold water pipe. Used some
steel wool to "shine up" a small section of pipe and wrapped several
inches of the stripped wire to the cleaned pipe, secured with a worm
clamp.
-
¯ barry.martinşATşthesafebbs.zeppole.com ®
* That reminds me, I must empty the bag on the vacuum cleaner.
w_tom
Add that distance to the length of wire, and length of wire on
surge protector. It must be less than 10 feet. How many
solder joints in that path? How many sharp bends? These also
conspire to create no good earth ground.
But then you don't want an earth ground. It is called
central earth ground. Single point grounding is necessary.
All incoming utilities must connect less than 10 feet to
single point earth ground.
You may have an improved earth ground - at the expense of
human safety and in violation of National Electrical Code.
Connections to water pipes are for removal of dangerous
currents to those pipes. It is intrinsically unsafe to ground
to water pipes with the intent of dumping electricity into
household water pipes. This is a change from what was
acceptable 30 years ago.
There is no way around this fact. Effective surge
protection must be located where the utility enters the
building so that connection from that utility, through surge
protector, to earth ground is less than 10 feet.
If those components inside a plug-in surge protector were
effective, then those $0.10 parts would already be inside the
appliance. Plug-in protectors don't even claim to provide
protection from the type of surge that typically damages
electronics. But then it gets worse. Being too close to
transistors and too far from earth ground, that protector can
even complete a circuit that damages an adjacent and powered
off appliance.
How to identify an ineffective surge protector. It has no
dedicated connection to central earth ground, and it avoids
all discussion about earthing. You plug-in protector would be
ineffective twice over.
Andy in Fink
However, ANY surge protector is better than NO
surge protector.
Some just don't work very well....
Complete isolation from external lines is always
the best option, such as:
Battery/Inverter power source with wireless
cell phone data link.
Too damn expensive for me, but I can dream... :>)))
Andy
trebor4258
"w_tom" <w_t...@hotmail.com> wrote in message
news:3EEE92B3...@hotmail.com...
If all that's the case, then riddle me this....
Several years ago, I had my entire computer system plugged into one multiple
outlet strip that had an internal MOV to ground. I had the strip plugged
into one of Radio Shack's ~$5 cube looking protectors. It's at least a very
fast MOV and maybe a little more. It's the one with the neon light inside.
When the MOV gets zapped, the neon light quits burning so you know it's bad.
I added a fax machine and didn't have an outlet in the strip for it, so like
the 20-something know it all I was, I just plugged it into the other socket
in the same outlet as the cube. Read that to mean fax machine directly to
commercial AC.
One day I came home and the little cube was not lit. I pulled it and
plugged the strip directly into the wall and everything still worked.
The fax machine was another story completely. It got hit so badly that the
neutral side of its plug had actually burned in two.
I ended up having to replace the fax machine and the outlet. And you can
bet your last a$$ that I bought another of those little Radio Shack
protectors. Actually, I've bought several more of them over the years.
The kind of circular discussions that grounding can start are usually
pointless. I've done my share of UPS systems, -48VDC systems with
batteries, antennas, etc. My conclusion is that nothing is impenetrable.
Nothing will protect you from a direct lightening hit. Surge suppressors do
have some (at least anecdotal) value and for less than $10 they're a good
investment.
trebor
Nick Pine
>...1 amp is approximately 120 watts.
So, 1 amp = 1 amp x 120 volts, therefore 1 = 120 volts.
>A higher Joule figure is better, but also relates to a duration figure.
>1,000,000 Joules at 500 milliseconds is better than 1,000,000
>Joules at 200 ms.
Or 1,000,000 joules at 1 nanosecond?
Nick
Nick Pine
>From what I have read if the ground isn't there the surge protector
>offers little if any protection -- where is the shunted voltage to go?
And how do you shunt a voltage?
Nick
Nick Pine
>...length of wire on surge protector. It must be less than 10 feet.
Why yes. Many houses with 10.0001' ground wires have burned down.
A tiny snip coulda saved them.
Nick
w_tom
failure analysis at component level. For example, what was
the incoming and outgoing surge path? Lightning is
electricity. First it forms a complete electrical path. Then
it damaged something in that path. One (typically) incoming
path would be AC plug. Now define the outgoing path. Only
then can we say specifically why that particular surge damage
happened.
We do know the Radio Shack surge protector was so grossly
undersized as to be damaged by the surge. That is obvious
because effective surge protectors remains functional after a
surge. We also know that lightning typically does not have
energy sufficient to cause that power cord to burn. That
burning would have been from utility power after surge had
done damage.
And it does not have to be a direct surge to your appliances
that did damage. Did you verify your primary surge protector
was earthed? To do so, visit the telephone pole holding
utility transformer. Is that transformer properly earthed or
did a stray car break that all so critical earth ground wire?
Either way, we know that a 'whole house' protector would
have been far more effective even if the primary protector had
failed.
Also we know that all those appliances were connected
directly to commercial AC. They are called shunt mode
protectors. They don't block surges. They connect to AC
mains just like another light bulb - to shunt. Shunts don't
sit in series between appliance and AC electric. Shunt mode
surge protectors sit in parallel connected as if a light
bulb. The appliance connected directly to AC mains whether in
wall receptacle OR in surge protector.
Surge protectors, properly installed, routinely protect from
direct strikes. Your telephone company's switching computer
(in the Central Office) repeatedly suffers direct strikes.
How often did it shutdown for three days to replace computer?
How often does that 911 operator remove headset and shutdown
for thunderstorms? These are facts. Your fax machine was
damaged because its human failed to install proper
protection. And that proper protection is not a plug-in
device.
We know how to protect from direct strikes. And we know
that plug-in protector is ineffective. We know that a surge
protector is only as effective as its earth ground which is
why effective surge protectors are located at the service
entrance and less than 10 feet from central earth ground.
djohnson
> Surge suppressors do
>have some (at least anecdotal) value and for less than $10 they're a good
>investment.
There's anecdotal evidence for lots of things. I only use surge
protectors because multi-outlet strips that don't even claim to be surge
protectors are crappy in other ways.
Most people who advocate surge protection seem to agree that:
*Cheap protectors are ineffective.
*To be effective, every connection to your computer that is directly or
indirectly outside has to be properly protected, including network,
modem, cable, printer, etc.
*Poor house wiring reduces the effectiveness.
*Some damage is unavoidable.
Assuming those facts are true, I reason the following:
A surge protector that will usually work has a significant cost. I'd
need at least 5 of them and probably more, to cover network and computer
gear on 3 different floors. If I overlook anything on the copper
network, I'm screwed[1]. None of my computers are anything close to
state of the art, so even assuming total destruction, I'm not out a huge
amount.
Based on that, I figure that if I avoid surge damage for 4 or so years,
I'm financially ahead by skipping real surge protection. I've done
that three times so far...
[1] Maybe I can propose wireless networking to my wife as insurance
that one computer won't take out the rest...
--
Vice President Dan Quayle:
"[It's] time for the human race to enter the solar system."
Don K
news:7qo1fvghg9hbqnjke...@4ax.com...
> [1] Maybe I can propose wireless networking to my wife as insurance
> that one computer won't take out the rest...
Or maybe an optical network.
Don
w_tom
protection. For example, the ethernet network is good for
about 2000 volts. However when damage occurs through that
interface, the human has failed to shunt an incoming utility
to central earth ground.
I did a repair of a surge damaged network. They were on
vacation when lightning struck. I know this surge circuit
because I traced it by replacing defective ICs - making
everything work again - with no future failures due to
overstress.
Surge entered via AC electric on two computer with plug-in
surge protectors. Those adjacent protectors put the surge
into each computer via green safety ground wire. Surge used
network cards to obtain a third computer. Network card on
third computer had damage to a different IC. Surge then found
earth ground from third computer, through modem and phone
line. Damage to modem's DAA section completed all repairs.
Example of how one must do analysis to learn how surges
damage electronics. Having done this type of analysis so many
times, I can state far beyond anecdotal evidence - a surge
protector is only as effective as its earth ground.
It is not about cheap protectors verse expensive
protectors. A cheap protector is equivalent to the expensive
protector of same joules rating. Joules - not brand name or
money - determine the quality of a surge protector. Earth
ground determines it effectiveness.
4 years proves nothing. Destructive surges occur,
typically, once every eight years.
The problem is that most people who recommend surge
protectors don't even know what a surge protector does. Too
many assume the protector stops, blocks, or absorbs a surge.
Most don't even know about earth ground because grossly
undersized, overpriced, overhyped, mislocated plug-in
protector manufacturers don't mention any of this. Their
education is almost totally from boxes on retail shelves.
In this thread is something unique. Someone who has built
surge protectors, has suffered educational successes and
disastrous damage, who reads material from serious, real word
experts on the subject include IEEE papers, and who was
trained as an electrical engineer some decades ago.
This person is quite blunt. Ineffective protector have no
dedicated earth ground AND avoids all discussion about
earthing. Best protection is also the least expensive per
protected appliance. Al those 'point of use' protector are too
much hype, too much money, and too little protection.
Previously posted were examples of 'whole house' surge
protectors - made effective by the all so important central
earth ground.
Nick Pine
> In this thread is something unique. Someone who has built
>surge protectors, has suffered educational successes and
>disastrous damage, who reads material from serious, real word
>experts on the subject include IEEE papers, and who was
>trained as an electrical engineer some decades ago.
In this thread is language unique, with suffering English education?
Nick
hchi...@hotmail.com
LOL!
For those that are still reading, w_tom will fight to have the last word on
surge protectors, and Nick will fight for the last word on the math and
measurements involved.
As long as a surge is a powerline surge, and the person wanting protection is a
homeowner and not just a resident in an apartment building, w_tom has a very
convincing argument for investing in whole house protection. However, when a
direct lightning strike occurs within the immediate area, and specifically
_past_ the electrical entrance to a house then all bets are off but one. The
only safe bet is equipment housed within some sort of grounded Faraday cage.
If whole house surge protectors protected against a direct strike within the
house, then the same logic would dictate that the power company could place a
single whole grid protector at the generating station.
It is also important to remember that in the area of a lightning strike there
are usually multiple leaders from the ground that are highly charged and may
carry some substantial current, even though that current isn't enough to create
a complete flash.
Of the multiple ground leaders, one commonly connects to the downward leader
and creates the main current path. This may appear as a random connection, but
the ground (dirt) resistance, local resistance of the air and rain patterns can
all be determining factors in which leader is chosen as the main leader.
For example, a normally non-conductive chimney might not only become conductive
with a coating of rain, but also be emitting enough heated or ionized gasses in
a plume to tip a strike in its direction. A solid ground at the electrical
entrance will not prevent the resultant lightning strike from flashing the
moisture within the chimney bricks into superheated steam and blowing bricks
off the chimney. Neither will that whole house unit prevent the bolt from
following an attached antenna lead-in down towards a good ground within a
televison set, thus damaging or destroying it.
w_tom
we install earthed lighting rods. Protection on incoming
utilities (including that incoming TV or satellite dish
antenna wire) require earthing with or without surge
protectors. Using both systems is typically sufficient
protection for residences such as FL, AZ/NM border region, and
(yes) parts of WV.
hchi...@hotmail.com wrote:
djohnson
>
> 4 years proves nothing. Destructive surges occur,
>typically, once every eight years.
The point I was making was that in order to have effective surge
protection, I'd have to spend a fairly large fraction of the value of
what I'm trying to protect. My wife has the best computer in the
house, it could be replaced for under $350. It isn't worth very much to
protect that small amount against a danger that slight.
--
"A central challenge of a free society faces in countering terrorism is in
maintaining its own character and protecting it's citizens while preserving
what makes the society worth protecting in the first place."
--Alison Mitchell
w_tom
appliance. You are not just protecting that computer. What
about your clock radio, microwave oven, portable phone, GFCI
that protects in bathroom and kitchen, dimmer switch, air
conditioner and furnace controls, touch on-off lamp, and
electronic timer switch. Effective 'whole house' protector
costs about same as one or a few, ineffective, plug-in surge
protectors. Visit Home Depot. Price Intermatic EG240RC or
Siemens QSA2020. How much is not the question. How
inexpensive?
The event is infrequent. The damage can be expensive - more
than just a computer and the lost data.
barry martin
T > The kind of circular discussions that grounding can start are usually
T > pointless. I've done my share of UPS systems, -48VDC systems with
T > batteries, antennas, etc. My conclusion is that nothing is impenetrable.
T > Nothing will protect you from a direct lightening hit. Surge suppressors d
T > have some (at least anecdotal) value and for less than $10 they're a good
T > investment.
Agreed. Some surge protection is better than none. I know of some
people who rotate their surge protectors yearly: buy top-of-the-line
to put at "Level 1" -- protection of such devices as computers and
expensive stereo systems. The formerly Level 1 surge gets demoted to
Level 2 to protect TVs, VCRs, etc. Formerly Level 2 become Level 3,
protection for the $29.99 telephone answering machine, etc. Theory
behind the rotation is there are constantly small surges from motors
starting up, etc., which chip away at the device providing the surge
protection, making it less efficient.
-
¯ barry.martinşATşthesafebbs.zeppole.com ®
* Hello, our names are Nat and Bea, we are entomologists.
Neil
> w_tom On Wed, 18 Jun 2003 23:39:24 -0400 wrote,
>
> >
> > 4 years proves nothing. Destructive surges occur,
> >typically, once every eight years.
>
> The point I was making was that in order to have effective surge
> protection, I'd have to spend a fairly large fraction of the value of
> what I'm trying to protect. My wife has the best computer in the
> house, it could be replaced for under $350. It isn't worth very much to
> protect that small amount against a danger that slight.
If you have renter's or homeowner's insurance, you might want to find
out if that will cover any damage due to electrical problems, surges,
etc.
Gene Wirchenko
>w_tom On Wed, 18 Jun 2003 23:39:24 -0400 wrote,
>> 4 years proves nothing. Destructive surges occur,
>>typically, once every eight years.
>
>The point I was making was that in order to have effective surge
>protection, I'd have to spend a fairly large fraction of the value of
>what I'm trying to protect. My wife has the best computer in the
>house, it could be replaced for under $350. It isn't worth very much to
>protect that small amount against a danger that slight.
Is the data worth anything? What happens if you lose it? Do you
have backups?
Calculating loss considering only the hardware's hard costs can
be shortsighted. YMMV, but check first!
Sincerely,
Gene Wirchenko
Computerese Irregular Verb Conjugation:
I have preferences.
You have biases.
He/She has prejudices.
djohnson
> Is the data worth anything? What happens if you lose it? Do you
>have backups?
>
> Calculating loss considering only the hardware's hard costs can
>be shortsighted. YMMV, but check first.
The critical stuff is backed up to CD. It would be a major annoyance to
put it all back, but not horrible.
--
Take my advice--I'm not using it.
Nick Pine
(ple...@intermatic.com, (800) 3911-4555), who had some actual numbers
concerning this black art :-) He said Intermatic is backing out of the
Home Depot market because homeowners typically need more support than
they can offer, and they are now selling $65 IG240RC surge suppressors
via electrical supply stores like Graybar. An IG240RC contains 6 MOVs
in various flavors at 150 and 275 V. The 150 V MOVs (across 120 V legs)
typically start to conduct at 200-215 V.
He said joules are obsolete as a way of rating suppressors. The ANSI/IEEE
C62.41 standard says we can expect less than 20 kV at less than 10 kA
from 0.1 to 0.4X per year, or less, outside of Florida, at the service
entrance (category C.) He mentioned NEMA LS-1 and UL TDSS 1449 standards.
Their IG1240RC is rated for a peak surge current of 32kA, with typical
50 microsecond (20 kHz) voltage and 28 microsecond current waveforms.
It has a 5-year guarantee. They ship about 25K units per year, with very
few returns. Most of the problems involve a bad neutral, with more than
120 V from one leg to ground. These are typically utility problems that
happen when neutral paths open or higher voltages (eg 7200 V) short to
the neutral.
Pete said their surge suppressors do not require special ground rods, just
a connection to panel neutral. He advised against special grounds, esp if
they are better than utility grounds. He said "If your utility has a 10 ohm
ground, you better not have less than 9 ohms, or you will become a magnet
for utility surges."
Nick
Warren Block
> An [Intermatic] IG240RC contains 6 MOVs
> in various flavors at 150 and 275 V. The 150 V MOVs (across 120 V legs)
> typically start to conduct at 200-215 V.
Do they recommend regular replacement because the MOVs degrade?
[Rest of post snipped; w_tom is gonna yell at you because you either did
or did not say what he thinks you might or might not have meant.]
--
Warren Block * Rapid City, South Dakota * USA
Nick Pine
>> An [Intermatic] IG240RC contains 6 MOVs in various flavors...
>Do they recommend regular replacement because the MOVs degrade?
Not until the lights on the box indicate failed MOVs, which rarely happens,
and falls within their 5 year guarantee. BTW, Intermatic's IG1300 also
protects phone and cable lines.
>[...w_tom is gonna yell at you because you either did or did not say
>what he thinks you might or might not have meant.]
While waving his stovepipe hat? :-)
Nick