Line conditioning (more newbie questions)
mb
day for my new CRT RP HD monitor draws near, I'd like to have everything
ready in terms of cabling. Obviously I'll be plugging the set and
components into a quality surge supressor, but I was wondering if the
"line conditioning" connections for the coax coming from the wall then
to the digital HD/DVR set-top box are worth using or even including in
my purchase? Instinctively I shy away from extra points of connections
for fear they will cause a weak link and degrade the signal. Thanks for
any thoughts.
mb
Pagan
news:MPG.1c59ef915...@news.east.cox.net...
Use them or not, it shouldn't matter. With digital, you either get a signal
or you don't. Instead of static or imperfections, the worst you are likely
to see is dropouts now and then, but if you subscribe to cable, you should
be used to that anyway. heh
You might as well use them, but if you really want my suggestion, try taking
your 'quality' surge suppressor back, use the money for a couple very cheap
power strips, and spend the rest on something more useful, like a UPS for
your DVR so if the power goes out, your shows will still be recorded. (also
is handy for cordless phones)
So-called 'quality' surge suppressors use the same components as cheapo
units, usually just a cap and a couple resistors, and they do wear out,
meaning that in a couple years you'll have a plain old power strip that
looks like a quality surge suppressor. It doesn't matter how pretty, heavy,
or shiny those things are either.
The most amusing thing is the Monster Cable power strip, which is supposed
to do all these great things with your power for about $200. For that
amount of money, and using solid and proven electrical principles, you can
get a dedicated circuit run from your 'fuse' box straight to the wall where
your fancy equipment resides. This will give you 'cleaner' power, do the
most to protect your gear from remote lightning and brownouts (which can
affect a single circuit in your home and destroy your stuff), and lesson the
amount of extension cords and power strips you need, further 'cleaning' your
power.
Anyway, as for your original question, if your cable/satellite system was
installed properly, you don't need that extra 'protection', or the extra
cable this thing probably didn't come with.
Pagan
tra...@optonline.net
thing you should get is a whole house surge protector that goes on the
main panel. Not only is it the most effective AC protection, it also
will protect everything in the house that is connected to the AC.
w_tom
might as well by a Monster protector. Might as well be
scammed by the best. A protector adjacent to electronics can
even contribute to damage of those electronics. It does not
even claim to protect from the type of transient that
typically damages electronics. It hopes you will not learn
that different types of transients exist.
What are you going to "line condition". A line conditioner
can only attenuate certain frequencies. Which frequencies do
you want to attenuate? IOW what good signals do you want to
eliminate? Attenuating signals is what a "line conditioner"
will do.
If you want the installation to installed correctly the
first time, then the single point earth ground must already
exist and already make a 'less than 10 foot' connection to
phone and AC electric 'whole house' protectors. Yes- phone
company provides a 'whole house' protector for free. But
cable will require no protector. Cable gets same protection
by first dropping down to the single point earth ground,
making a very short wire connection to that earth ground, then
rising back up to enter the building. They cannot do this
(must install compromised protection) if you have not
installed a single point ground.
The most common source of destructive transients are those
wires highest on poles that connect that transient directly to
your electronics. As trader has properly posted: you want a
'whole house' protector on AC mains that makes a 'less than 10
foot' connection to that earth ground.
The plug-in protector costs more and provides no effective
protection. Read their own specs for the so many missing
facts. Where do they claim protection for each type of
transient? Where do they provide a dedicated connection to or
even discuss single point earth ground? No wonder it
typically also has too few joules.
Learn from another's damage even though he had a plug-in
protector:
"network card and modem not working" on 3 Sept 2003 in
newsgroup microsoft.public.windowsme.hardware at
http://tinyurl.com/5h82o
which in turn cites another discussion on technical details.
edee em
"power bar" that offers a good insurance guarantee, or is that just part of
the scam???
"w_tom" <w_t...@hotmail.com> wrote in message
news:41F18B30...@hotmail.com...
Pagan
news:bngId.743$vr4...@read1.cgocable.net...
> Given all of the above, would it still not be prudent to buy some form of
> "power bar" that offers a good insurance guarantee, or is that just part
of
> the scam???
It's an even bigger part of the scam. You have to jump through so many
hoops and prove the unprovable in order to collect on their 'insurance'.
If you want the greatest protection, you can install a whole house protector
(the benefits of which I am still dubious, at least for a reasonable amount
of money, though I may be wrong there), a dedicated circuit to your AV
system, and a Good UPS on the system itself (which has the benefit of
backing up your PVR in case power fails, ensuring your shows still get
recorded).
Frankly, unless you actually have problems with your wiring,
super-power-hungry appliances (welders, burst radar, EMP weapons), or power
supply from the plant, there is little to fear.
The power clamping alone on practically all sub $100 devices is pathetic.
Sure, it can stop spikes up to 400, 300, or even 200 volts. Ask any veteran
who served in Europe if 200 volts is enough to blow your gear. Plenty of
careless folks plug 110 volt stuff into Europe's 220 volt plugs, burning the
crap out of them.
Now consider the millions of people in the US alone who have these 'line
conditioners' which do pretty much nothing to protect their electronics. If
there was a major problem with the power in the US, things would be dying
all the time, people would bitch, and it would get fixed.
Some cities do have problems, mostly small towns which generate their own
power. If this is the case, then sure, a UPS, whole house conditioner, or
other means of protection may be a good idea. However, it may be just
wasted money. You can ask local electritions you trust about that. Asking
the kid at Best Buy while he's standing next to a $500 rack mount line
conditioner with an LED display is a bad idea. In fact, those things are a
bigger rip off. Practically every appliance that wasn't made in South China
can tolerate some voltage deviation, and most of those can too. Some PC
power supplies can put up with an input voltage of 90 volts without missing
a beat, despite the fact that a PC's innards are exceedingly sensitive to
power fluctuations.
Pagan
mb
apartment complex where filtering the main coming into my unit not being
an option alter any of these points?
mb
w_tom
Their warranty - $0. Generally, the larger that warranty,
then the less effective that protector. You want insurance.
Go to a broker who must provide the details up front and who
must honor that policy.
Did you read some of the exemptions in warranties attached
to ineffective protectors? Should you use a protector from
any other manufacturer, then the first manufacturer need not
honor your claim. When selling ineffective protectors, then
include an ineffective warranty.
Start you analysis thus. Is a dedicated connection to earth
ground missing? Does it avoid all discussion about earthing?
Both are symptoms of ineffective protectors.
w_tom
properly earthed. Some have a utility transformer right at
the service entrance that could mean all AC electric lines are
earthed. Unfortunately, you don't know.
If the building is steel and concrete, then steel I-beam
that a breaker box is mounted or connected to is earth
ground. A 'whole house' protector at that mains breaker box
would then provide effective protection.
Cable, if properly installed, also first connects to same
single point ground before entering building. Sometimes the
apartment management cannot be bothered to let it be installed
properly. Its not their electronics.
Pagan
> I appreciate everyone's input. Would living in a large multi-unit
> apartment complex where filtering the main coming into my unit not being
> an option alter any of these points?
For really expensive stuff, a medium end UPS from an established
manufacturer would do well.
The only real problem you may have is others in the complex deciding to do
some welding or something, and that's hardly a 'real' problem unless you
live in a place like I used to live in. (read White Trash Ghetto) heh
A UPS will do more to filter out spikes and drops more than any wild and
expensive 'conditioner' could, despite their wacky marketing claims.
These can be had for under $100, some as low as $25, though those cheapos
aren't big on quality. For about $150 to $200, you would be as secure as
you can hope for. Don't bother spending more than that, because at that
level, where you have to have something reasonably small and portable, you
aren't going to get any more significant protection.
Again, I doubt you have anything to worry about. If you are in even a
moderately good sized city, your power is going to be good. If it weren't,
businesses and factories all over would be bitching to high hell about it,
as their power requirements are generally big to damn huge, and the effects
of even a small fluctuation in the mains voltage or sine wave would be
amplified like crazy, causing massive losses in expensive equipment.
Personally, unless you have other compelling reasons for buying a UPS, I
wouldn't worry about it.
Now if your protecting Yamaha's new flagship receiver, which costs $4500,
then yes, you might want to be more careful.
Pagan
MATTY
your equipment is damaged by a surge thru their surge protector...read
it very carefully.they all say the same thing..basically they will pay
if you use the surge protector within its rated spec...now theres the
trick..see with in its rated spec the equipment wont be damaged and so
they dont have a problem.if the surge is higher than their rated spec
which pretty much means anything that gets thru and damages your stuff
then it gives them an out not to pay if they choose....voltage spikes
can run pretty high and no strip will stop a lightning surge on a power
system....
Dave Oldridge
news:10v3bob...@corp.supernews.com:
> "edee em" <ema...@cogeco.ca> wrote in message
> news:bngId.743$vr4...@read1.cgocable.net...
>> Given all of the above, would it still not be prudent to buy some
>> form of "power bar" that offers a good insurance guarantee, or is
>> that just part
> of
>> the scam???
>
> It's an even bigger part of the scam. You have to jump through so
> many hoops and prove the unprovable in order to collect on their
> 'insurance'.
>
> If you want the greatest protection, you can install a whole house
> protector (the benefits of which I am still dubious, at least for a
> reasonable amount of money, though I may be wrong there), a dedicated
> circuit to your AV system, and a Good UPS on the system itself (which
> has the benefit of backing up your PVR in case power fails, ensuring
> your shows still get recorded).
>
> Frankly, unless you actually have problems with your wiring,
> super-power-hungry appliances (welders, burst radar, EMP weapons), or
> power supply from the plant, there is little to fear.
>
> The power clamping alone on practically all sub $100 devices is
> pathetic. Sure, it can stop spikes up to 400, 300, or even 200 volts.
> Ask any veteran who served in Europe if 200 volts is enough to blow
> your gear. Plenty of careless folks plug 110 volt stuff into Europe's
> 220 volt plugs, burning the crap out of them.
Most really good UPS devices of sufficient capacity to run your stuff for
a few minutes will drop the line like a hot potato if they see an
incoming surge. And that's usually protection enough (the sensing
circuits in those are quite robust). I had one once that put out 800
watts but came with a warning that if its internal fuse ever blew to call
the power company immediately because the one in the pole peg was
probably gone, too!
> Now consider the millions of people in the US alone who have these
> 'line conditioners' which do pretty much nothing to protect their
> electronics. If there was a major problem with the power in the US,
> things would be dying all the time, people would bitch, and it would
> get fixed.
>
> Some cities do have problems, mostly small towns which generate their
> own power. If this is the case, then sure, a UPS, whole house
> conditioner, or other means of protection may be a good idea.
Yep...I used to live in a part of suburban Halifax that got all kinds of
neat spikes, from lightning and from idiot local slackjaws who shot out
high tension power lines in order to rob convenience stores with the
cameras off.
> However, it may be just wasted money. You can ask local electritions
> you trust about that. Asking the kid at Best Buy while he's standing
> next to a $500 rack mount line conditioner with an LED display is a
> bad idea. In fact, those things are a bigger rip off. Practically
> every appliance that wasn't made in South China can tolerate some
> voltage deviation, and most of those can too. Some PC power supplies
> can put up with an input voltage of 90 volts without missing a beat,
> despite the fact that a PC's innards are exceedingly sensitive to
> power fluctuations.
Yep...and PC's power supply has some very good regulators for just that
reason.
--
Dave Oldridge+
ICQ 1800667
A false witness is worse than no witness at all.
w_tom
the line' if it sees an incoming transient? Let's assume it
does. Well a destructive transient takes only microseconds.
The UPS takes milliseconds to 'drop the line'. IOW 300
consecutive transients would pass through a plug-in UPS to
damage electronics before that UPS even considered 'dropping
the line'. Furthermore, the line that gets switched open is
not necessarily the wire that carries destructive transients
into the computer. Hardware protection from a plug-in UPS is
a myth. Manufacturer does not even claim to provide the
hardware protection being promoted.
Plug-in UPS is for data protection. When power is lost,
then the UPS takes milliseconds to switch over to battery.
Just another reason why a power supply must meet Intel
standards. A power supply must supply power for tens of
milliseconds while the UPS decides power has been lost; and
then switchover from lines to batteries.
Numbers say the UPS cannot possibily 'drop the line' fast
enough. The plug-in UPS is for data protection - so that a
power loss will not destroy unsaved data. The UPS does not
even claim to protect from transients that would typically
damage hardware. Even the numbers - microseconds verses
milliseconds - makes that obvious.
Dave Oldridge wrote:
> Most really good UPS devices of sufficient capacity to run your stuff
> for a few minutes will drop the line like a hot potato if they see an
> incoming surge. And that's usually protection enough (the sensing
> circuits in those are quite robust). I had one once that put out 800
> watts but came with a warning that if its internal fuse ever blew to
> call the power company immediately because the one in the pole peg
> was probably gone, too! ...
Pagan
> Sounds good ... until we include numbers. Will a UPS 'drop
> the line' if it sees an incoming transient? Let's assume it
> does. Well a destructive transient takes only microseconds.
> The UPS takes milliseconds to 'drop the line'. IOW 300
> consecutive transients would pass through a plug-in UPS to
> damage electronics before that UPS even considered 'dropping
> the line'. Furthermore, the line that gets switched open is
> not necessarily the wire that carries destructive transients
> into the computer. Hardware protection from a plug-in UPS is
> a myth. Manufacturer does not even claim to provide the
> hardware protection being promoted.
There are reasons for that that have nothing to do with electronics.
Legally, they must be more careful, as their target customers are
businesses.
Even a budget UPS (not always a cheapo) will provide some protection, due to
their inherent design, and that protection is much better than a cheesy
'line conditioner' with a capacitor and, on really high end ones, a circuit
breaker, which is quite useless.
Get one with a quick blow fuse, and that might help a little, unless the
device your hooking up draws a lot of power on startup or occasionally
during operation, such as a TV or computer monitor.
Anyway, the poster who started this thread lives in an apartment, and
inquired about a way to protect his gear. Certainly a UPS is better than a
fancy and expensive surge suppresor with a bogus warranty. It also offers
protection from a more realistic danger to those living in a large building
with a bunch of other people, that of voltage drops.
> Plug-in UPS is for data protection. When power is lost,
> then the UPS takes milliseconds to switch over to battery.
> Just another reason why a power supply must meet Intel
> standards. A power supply must supply power for tens of
> milliseconds while the UPS decides power has been lost; and
> then switchover from lines to batteries.
Depends on the UPS. A 'continuous' UPS is always running off battery power,
and at the same time charges the battery. When power is lost, there is no
switch over, unless you could the circuit that keeps the charger itself from
draining the battery when it's not charging. These provide exceedingly
'clean' power, and plenty of protection.
As for a PC power supply, I used that as an example to those who loose sleep
worrying about which surge suppressor to buy. In fact, many PC power
supplies don't even meet their own standards, using crappy components and
relying on the motherboard to regulate power. Try to run them near their
rated capacity, and they tend to poop out. However, even these crappy power
supplies can clean up the power somewhat, certainly well enough for the
average user.
> Numbers say the UPS cannot possibily 'drop the line' fast
> enough. The plug-in UPS is for data protection - so that a
> power loss will not destroy unsaved data. The UPS does not
> even claim to protect from transients that would typically
> damage hardware. Even the numbers - microseconds verses
> milliseconds - makes that obvious.
The fact is a dedicated circuit to whatever device offers more protection
than any surge suppressor, although it's not always within the user's
ability to install one. However, I have yet to see this described on any
literature selling surge suppressors or line conditioners, even though it is
indeed obvious.
Pagan
MATTY
voltage spikes on that line .a lightning strike or downed utility pole
will still fry your equipment.a ups either off line or on-line style
will still pass thru sizable spikes as even on the on line type has
monitoring circuits that are connected to the power lines.at all
times....ups systems have the same line filtering as most line
conditioners....
w_tom
suggested, then a typically destructive transient would enter
electronics through power supply. But power supply is not the
most common path of destructive transients from AC mains.
First, power supplies already have the protection that would
be provided by a continuous or always on-line UPS. Second,
that always on-line UPS costs on the order of $500. A many
times cost increase just to obtain some alleged protection.
Third, to provide the protection theoretically provided by
that always on-line UPS, then the UPS must provide protection
by stopping, blocking, absorbing, or filtering the destructive
transient. Does not happen. IOW the UPS is going stop what
miles of sky does not? Of course not.
Three reasons immediately say that plug-in UPS is not a
solution. Now we include the numbers.
Again, if the always on-line and so many times more
expensive UPS can stop, block, or absorb a typically
destructive transient, then the power supply has already
provided sufficient protection. For computers, if that power
supply does not have such standard circuits, then the crappy
$25 supply should be disposed and replaced with any of many
that do provide protection but cost so much more. That so
much more effective supply is $60. Which do we do? Spend
$500 on a plug-in UPS or $60 for the minimally sufficient
power supply? Any isolation provided by the on-line UPS must
already be part of a computer's power supply and part of any
other electronic supply. So what does the $500 on-line UPS
provide? Nothing if a power supply meets defacto standards of
even 30 years ago.
That is the point. Any power supply that meets industry
standard specs provides protection that may be installed on
the other end of that 6 foot power cord. Internal protection
is fully effective (not overwhelmed) IF the typically
destructive transient is earthed at the service entrance. If
an always on-line UPS is to be effective for the OP, then he
already has same protection inside his electronic's power
supply.
In the meantime, a quick blow fuse is about same protection
as the typical plug-in UPS. Fastest fuses still take
milliseconds to blow. Destructive transients have done damage
in microseconds.
One further point. If a fuse blows due to a destructive
transient, then the fuse continues to conduct until that
transient subsides. Notice voltage ratings on fuses. A 250
volt fuse is not rated disconnect a 500 volt transient. Just
another reason why fuses do not protect from typically
destructive transients.
Two more sets of numbers that demonstrate fuses do not
provide protection.
What is the protection circuit in most UPSes? Same circuit
using same components found in power strip protectors. Just
one more reason why plug-in UPSes do not provide effective
protection. If a power strip protector is not effective, then
either is the same circuit used in a plug-in UPS.
Dedicated circuit or isolated ground are other myths also
provided to provide protection. Destructive transients will
enter electronics on that circuit whether it is dedicated or
shared. Dedicated circuit or isolated ground are more
expensive solutions without first identifying the problem.
Neither will stop, block, filter, absorb, or shunt the
destructive transient. Anything that works at the computer
must already be inside that power supply.
How much is that minimally sufficient power supply? For
computers - about $60 retail. Far more effective solution is
to buy electronics from responsible manufacturers and not buy
computer power supplies that sell for less money by forgetting
essential internal functions. A $500 UPS is not a good
solution to electronics designed by and for bean counters.
Dave Oldridge
> Sounds good ... until we include numbers. Will a UPS 'drop
> the line' if it sees an incoming transient? Let's assume it
> does. Well a destructive transient takes only microseconds.
> The UPS takes milliseconds to 'drop the line'. IOW 300
> consecutive transients would pass through a plug-in UPS to
> damage electronics before that UPS even considered 'dropping
> the line'. Furthermore, the line that gets switched open is
> not necessarily the wire that carries destructive transients
> into the computer. Hardware protection from a plug-in UPS is
> a myth. Manufacturer does not even claim to provide the
> hardware protection being promoted.
>
> Plug-in UPS is for data protection. When power is lost,
> then the UPS takes milliseconds to switch over to battery.
> Just another reason why a power supply must meet Intel
> standards. A power supply must supply power for tens of
> milliseconds while the UPS decides power has been lost; and
> then switchover from lines to batteries.
>
> Numbers say the UPS cannot possibily 'drop the line' fast
> enough. The plug-in UPS is for data protection - so that a
> power loss will not destroy unsaved data. The UPS does not
> even claim to protect from transients that would typically
> damage hardware. Even the numbers - microseconds verses
> milliseconds - makes that obvious.
The thing is, those microsecond surges rarely make it past the power
supply unless they are showing up on other wires. The worst damage I've
ever had to computer equipment came from a surge over an UNDERGROUND
ethernet line in a thunderstorm. In fact that coax got to be SO
notorious that we put a cheap hub at either end of it and just replaced
the hubs when there was a thunderstorm (it was about 200 feet underground
from our office to our ISP's).
And TV's are about the same. A microsecond surge is going to do more
damage on a cable or antenna lead in than it will on the power pipe.
They are just so short in duration that the capacitors in the power
supplies usually buffer the energy regardless of voltages.
That said, the BEST protection during thunderstorms, and I speak from
experience here, is pulling ALL plugs from the power sockets and removing
all outside antenna, cable and network connections from all devices.
Of course you sort of have to BE there to do that!
Dave Oldridge
Uh, fuses are not there to protect against voltage spikes. The job of a
fuse or circuit breaker is to protect the power source AFTER something
downwind of the fuse has failed. A 250 volt fuse is quite adequate to
protect a 110 volt circuit from shorts, since it will blow and shut
everything south of it down, thus protecting what's north.
> Two more sets of numbers that demonstrate fuses do not
> provide protection.
But you're right about them not protecting against voltage spikes. Fuses
only blow if the current exceeds their limit for some specified time,
usually in ms, but sometimes in seconds if it's a slow-blow fuse.
> What is the protection circuit in most UPSes? Same circuit
> using same components found in power strip protectors. Just
> one more reason why plug-in UPSes do not provide effective
> protection. If a power strip protector is not effective, then
> either is the same circuit used in a plug-in UPS.
> Dedicated circuit or isolated ground are other myths also
> provided to provide protection. Destructive transients will
> enter electronics on that circuit whether it is dedicated or
> shared. Dedicated circuit or isolated ground are more
> expensive solutions without first identifying the problem.
> Neither will stop, block, filter, absorb, or shunt the
> destructive transient. Anything that works at the computer
> must already be inside that power supply.
Look, the only REAL protection from lightning is isolation, pure and
simple. I've never seen an induced lightning spike jump even a foot (4
inches is another story!). And those are the most common killers of
electronics in my experience (lost 4 modems, two ethernet cards--
repairable--and a monitor in one strike and the whole computer except for
the hard drive in another). In the first case the lightning entered the
premises through the phone line and jumped into the etherenet wiring in
the building. In the second, it came in, as I stated elsewhere, via an
underground ethernet. The latter proved to be a chronic problem as the
offices were situated on a fairly high spot with a huge metal flagpole
just 100 feet away. The induced surges on the ethernet were a HUGE
problem, but once we isolated that piece of wire, the power wiring gave
us zero problems. I even ran one computer in that office for six months
straight without a reboot.
MATTY
theres 3 basic kinds of ups systems.
the first and cheapest is a standby ups.these are the usual under 200
buck type...they run on ac first and then switch to battary on power
failure or a surge above a preset level..they take every hit as far as
spikes and surges
2nd type is a line interactive---these cost more ,still run on ac power
first but contain voltage regulation and spike and surge
protection..better than a standby unit in regards to spikes and surges
but not a whole lot better]\
3rd type is a on-line...these are the most expensive ,they run on
battary power and are totaly off the line except for the battary
charger..the ac only recharges the battary....maintainance is high on
these as the battaries are very expensive and need to be replaced ofton
as they are always working...these provide total line isolation....
Mr Fixit
great, but of little help to the layman trying to protect their home
entertainment center (or PC), etc. I would therefore like to suggest
anyone confused by all of this to visit the following web site where it's
all explained, including some low cost recommendations:
Pagan
news:gnf7v0d59kcluofng...@4ax.com...
You are correct. I'm not sure how this discussion went from that to wild
theory on what doesn't work, with nobody mentioning what does work.
Fact is, there is nothing going to protect against millions of volts of an
unfortunately placed lighting strike, and if the power supply from the mains
is so bad folks need to spend hundreds or thousands of dollars to protect a
PC or stereo, then it might be time to move, or just run everything off a
generator.
Pagan
tra...@optonline.net
in an apartment so you don't have control over whether a whole house
type surge supressor is in fact deployed on the AC where it enters the
building. In that situation, I would use a good stand alone surge
protector, which is not as effective, but can offer protection. There
are certainly many folks like me, who have seen this type of protector
save equipment while other nearby equipment was zapped.
And I wouldn't be concerned about power line conditioning, which is
really something quite different. You want to protect against the
large voltage spike that can be created by a lightening strike,
possibly a long way away, appearing on the lines. More subtle noise or
voltage fluctuations aren't going to harm your gear. A stand alone
protector isn't perfect, but for your case, it's certainly an
appropriate solution. I wouldn't spend extra money for one with a
guarantee, unless you can find people who have in fact used the
guarantee and had received compensation.
w_tom
then electronic power supplies already contain sufficient
protection. Power supplies already have galvanic isolation.
So why is that not sufficient? Because lightning voltages
(not shunted to earth) will increase, as necessary, to
overwhelm isolation. This concept called current source is
from first year electrical engineering. But you need not
understand that. If not earthed, then transient voltages will
increase as necessary to overwhelm isolation.
Effective protection has always been about earthing before
the transient can enter a building. Does a telco use
isolation to protect their $multimillion computer from the
miles of wire overhead and everywhere in town? Of course
not. They too use same principle that Ben Franklin
demonstrated in 1752. Earthing.
Posted so many times was the solution for all homeowners.
This in my very first post:
> If you want the installation to [be] installed correctly the
> first time, then the single point earth ground must already
> exist and already make a 'less then 10 foot' connection to
> phone and AC electric 'whole house' protectors.
Bottom line fact: a surge protector is only as effective as
its earth ground. No earth ground means no effective
protection.
Lets review some of Dave's examples. First, the naive often
assume lightning entered via phone line only because modem was
damaged. How did lightning avoid the telco installed 'whole
house' protector? Second, an assumption that electricity
enters a building, damages something, then stops is nonsense.
Electricity first forms a complete electrical circuit as is
taught in elementary school science. No circuit means no
electricity. Only then does something or many things in that
electric circuit fail. First a complete circuit must exist
which means everything damaged must first have an incoming and
outgoing electrical path.
The most common source of modem damage is a strike to wires
highest on pole (wires that would protect the phone line from
being struck - just another reason transient did not enter on
phone line). Transient enters on AC mains seeking earth
ground. We use elementary school science (about electricity);
find a complete circuit. Incoming on AC electric, through
computer, out via modem, down phone line to earth ground.
Modem damage is most commonly created by transients entering
on AC mains - not incoming on phone lines. We now have a
complete circuit from cloud to earth that explains modem
damage.
What was the incoming and outgoing circuit path? Without
both an incoming and outgoing path, then transients cannot
damage electronics. 'Surge entered on phone line to damage
modem' is often a myth promoted by forgetting basic technical
knowledge - such as lessons from elementary school science.
Same transient has been demonstrated (by replacing ICs) to
enter a building (computers were powered off). Enters on AC
mains. Two plug-in protectors provided that transient with
more wires to destructively enter adjacent computers.
Transient then exited on network cards to obtain a third
computer (that had no plug-in protector). Transient incoming
through network card and out via the modem (this was the only
computer with a modem) to earth ground. Transient circuit was
proven by replacing every damaged IC in that circuit path.
Notice every damaged part had the prerequisite incoming and
outgoing electrical path.
First transient forms a complete circuit from cloud to earth
via electronics. Then damage occurs someplace in that
circuit. Modem was not damaged from a transient on phone line
(exemptions due to multiple earth grounds ignored for the
moment).
The second example: Did a struck flag pole 100 feet away
induce surges? Again a classic myth. We earth direct
lightning strikes down a lightning rod where down wire is only
four feet from a computer. The direct lightning strike (and
fields on that downlead wire) did not even reboot the
computer. How does a lightning strike 100 feet away have
sufficient fields when a wire only 4 feet away could not even
reboot the computer - let alone damage anything? These
'induced fields' are hyped routinely without numbers. Once we
apply numbers, those fields just are not destructive.
BTW, why are plug-in UPSes and power strips not effective
protection? The path to earth ground is bundled tightly with
other wires. IOW the plug-in protector causes 'induced
transients'. Wire with transient must be bundled with other
wires to induce a transient on those other wires. This is
dicussed extensively in IEEE papers.
But the flag pole can make a direct electrical connection to
electronics inside the building.
Problem more likely was created by a buried conduit, pipe,
or other conductive material (or soil) that carries the
transient into the building. This figure from the National
Institute of Standards and Technology demonstrate how multiple
earth ground and other grounding problems can created (some
will claim "induce") destructive transients inside a
building. Fax machine damaged because building did not have
the all so critical 'single point earth ground':
http://www.epri-peac.com/tutorials/sol01tut.html
Same problem can be created by AC electric lines that
terminates at the last building. Same problem is demonstrated
by four legged animals that are killed when lightning strikes,
for example, a nearby tree. Was that horse killed by an
induced transient? Of course not. The complete electric
circuit was down tree, through ground, up horse hind legs, and
down horses front legs. Horse was part of a complete
electrical circuit. One must first learn a complete circuit
from cloud to earth to discover reasons for damage - or dead
animals.
Isolation may have simply taken the one electronic device
out of a circuit that is incoming at flag pole, enters
building on left side earth ground, rises up through
electronics, crosses building, then drops back down to another
earth ground on building right side. Same circuit that also
killed the horse. Notice the "induced surge" is a myth caused
by not first learning the numbers (note: no Electromagnetic
Field numbers were provided to prove that induced surge
because the number don't exist).
Unfortunately, Dave has posted classic myths about
lightning. First, a complete circuit must be defined. One
does not stop, block, filter, absorb, or isolate such
transients. Those transients are shunted - which means a
complete transient circuit must be understood.
Homeowners have very easy solutions. Begin with the single
point ground that would also conform to post 1990 National
Electrical Code requirements. Then every incoming utility
makes a direct connection to that single point ground either
by direct wire (cable TV and satellite dish) or via a 'whole
house' protector (AC electric and phones). Right there, we
have shunted a transient to earth before transient gets to
electronics. Since the transient is earthed, then galvanic
isolation that exists in all electronics will not be
overwhelmed. Electronic damage avoided because human did his
job.
Any isolation that will be effective already exists in
electronics. Internal electronic appliance protection assumes
you (the homeowner) has routed all incoming utilities to first
make a short ('less than 10 foot') connection to earth
ground. This is about as simple and obvious as can be
explained. This sentence bluntly defines #1 step in transient
protection (also provides human safety requirements).
Transient protection is all about earthing. The most
critical component of that protection system is a single point
ground. No complex for any homeowner to comprehend.
BTW, all homeowners should appreciate we are only discussing
secondary protection. Homeowners must also inspect their
primary protection:
http://www.tvtower.com/fpl.html
Again, notice the one essential component - single point
ground. Isolation that will be effective is already inside
electronics. Isolation what works IF homeowner has properly
earthed all incoming utilities to the single point ground.
Dave Oldridge wrote:
> ...
w_tom
errors. Basically it is a soap box for myths encouraged by
the plug-in protector industry. First pages of that
irresponsible web site were critiqued in austin.general on
2 Apr 2003 entitled "New Computer in Austin... Keeping it
cool" or at:
http://tinyurl.com/2j934
Ironically I described, in my very first post, how to install
effective protection:
> If you want the installation to installed correctly the
> first time, then the single point earth ground must
> already exist and already make a 'less than 10 foot'
> connection to phone and AC electric 'whole house'
> protectors.
Then this was posted:
> A 'whole house' protector at that mains breaker box would
> then provide effective protection.
And this:
> Learn from another's damage even though he had a plug-in
> protector:
> "network card and modem not working" on 3 Sept 2003 in
> newsgroup microsoft.public.windowsme.hardware at
> http://tinyurl.com/5h82o
> which in turn cites another discussion on technical
> details.
Review that 'HowStuffWorks' website to learn how myths and
outright lies are promoted. There is no effective protection
listed in that 'HowStuffWorks' web site.
A 'cut to the chase' was posted many times previously. Also
included in that previous 3 Sept 2003 discussion were specific
model numbers and other examples. All comes back to the same
point that the 'HowStuffWorks' does completely avoid
discussing: a surge protector is only as effective as its
earth ground. You know that 'HowStuffWorks' piece is flawed.
They don't even mention earthing. No earth ground means no
effective protection.
w_tom
How did the transient enter through network card and not enter
through power supply? Well the network card was connected
directly to a large lightning rod - called the other
building. Damage was due to a fundamental violation of
protection. That ethernet wire must connect (via a protector)
less than 10 feet to the single point ground before entering
and leaving each building. Lightning struck one building,
exited via the ethernet cable, entered computer in second
building, exited maybe into second building's safety ground,
and then into earth. Now we have defined the complete circuit
from cloud to earth.
Again we demonstrate that damage is directly traceable to an
incoming wire that did not first connect to the building's
single point earth ground. Again we demonstrated that
isolation exists and was overwhelmed because the single point
ground was not provided. Again we have demonstrated damage
that no plug-in UPS or power strip protector would eliminate.
Furthermore, transients need not pass through a power
supply. The adjacent UPS or power strip protector simple
distributes (shunts) a destructive transient to all wires. IOW
the plug-in UPS or protector simply gives a destructive
transient other paths through adjacent electronics. Now the
transient has many more paths to enter and damage adjacent
electronics. And so we have the most common destructive
path. Incoming on AC electric green wire. Bypasses power
supply (and any isolation provided by an interactive or
continuously on-line UPS) to connect directly to motherboard.
Through motherboard into modem via the PNP transistor that
drives modem's off hook relay. Into relay coil. Through
isolation inside that relay to relay wipers. Then out to
earth ground via phone line.
Classic example of how modems are damaged. Specific
components listed because I have diagnosed and repaired this
so often. One most commonly damaged component in that modem's
DAA section (more buzz words due to extensive experience and
underlying theory) is that PNP transistor.
Notice in every case, the problem is created because the
human did not install and connect to a single point earth
ground. Also notice that any protection 'claimed' for a UPS
is simply bypassed. Where is the isolation of an interactive
UPS when the green wire carries destructive transients
completely around that UPS? Welcome to concepts that were
well understood even before WWII.
Can protection be obtained by unplugging everything? Well
the human is available at most only 1/3rd of the day.
Furthermore how is the human suppose to know of every incoming
transient before it can happen. Human want protection that
works every time and that is available 24/7. This is called
'whole house' protector that costs about $1 per protected
appliance. You tell me which the human should do? Unplug
every clock radio, electric clock, smoke detector, bathroom
and kitchen GFCI, and dimmer switch because he suspects a
thunderstorm? Or pay $1 to protect each appliance
constantly? This is not a difficult decision. Do what
mankind has been doing since 1752 when Ben Franklin
demonstrated effective protection - and it costs so little.
Pagan
<snip>
> A 'cut to the chase' was posted many times previously. Also
> included in that previous 3 Sept 2003 discussion were specific
> model numbers and other examples. All comes back to the same
> point that the 'HowStuffWorks' does completely avoid
> discussing: a surge protector is only as effective as its
> earth ground. You know that 'HowStuffWorks' piece is flawed.
> They don't even mention earthing. No earth ground means no
> effective protection.
No argument there, however, the poster who first asked how to protect his
system lives in an apartment complex. As the manager would probably not
appreciate one of the tenents making electrical and possibly structural
changes to the building's power supply, and since the manager is obligated
to provide a secure electrical supply by his liability, it's probably safe,
or at least practical, to assume the ground is good.
That being said, the biggest danger in this instance, from what I see, is
localized surges and dropoffs caused by other tenents.
Pagan
Dave Oldridge
Wrong. Electronic switches and fuses typically provide an isolation that
can be measured in mm of air or vacuum. Induced spike voltages can
easily jump that. But even a foot of air is capable of insulating some
pretty enormous voltages. Go look up the tables for the necessary
voltages to jump various distances in dry air if you doubt me. Pulling
the wires that lead to the outside right off the equipment is the BEST
way to ensure against lightning damage. It won't save you from a direct
hit but 99% of lightning damage to electronics equipment is from induced
surges in wiring, not direct strikes.
Think of the wiring in and around your equipment as being a sort of
antenna and the lightning strike as being a very strong nearby
transmitter (because that's actually more or less what is happening). If
you keep the antenna very short, that keeps the induced voltages down.
For one thing it severely limits the frequencies at which the system will
resonate. For another, for a given conductor diameter, the voltage will
be larger at longer wavelengths.
> you (the homeowner) has routed all incoming utilities to first
> make a short ('less than 10 foot') connection to earth
> ground. This is about as simple and obvious as can be
> explained. This sentence bluntly defines #1 step in transient
> protection (also provides human safety requirements).
There is nothing wrong with doing this, but it is not necessarily the
protection you think it is. It will still put high voltages at your
equipment on wavelengths that are odd multiples of 1/4 wave at the length
of the grounding connection.
> Transient protection is all about earthing. The most
> critical component of that protection system is a single point
> ground. No complex for any homeowner to comprehend.
That will no doubt help with power line spikes that usually come in on
the conductors and the ground in parallel, but it is NOT a solution for
spikes that arrive via antenna leads, telephone connections (though
grounding may help these somewhat) and network wiring.
Believe me, I've been through this. That building we had all the trouble
in with the 200 foot underground ethernet cable had EVERYTHING earthed
six ways to Sunday. But that 200 foot underground line would pick up
enough voltage every thunderstorm to smash out the ethernet cards at
either end. We would have used wireless, but it wasn't available at that
time, so we just bought cheap hubs and replaced as needed, either
replacing the hub or the damaged chip, whichever was practical.
But all the grounding in the world did not help. I mean we're talking
about a coaxial cable, earthed at both ends and STILL it built up
voltages.
The ethernet wiring in my trailer used to pick up spikes, too, but not
such large ones. Usually I was there to pull all the plugs out during a
storm. If there was no easy path from the wall socket to the equipment,
from an antenna to the equipment and from the phone line to the
equipment, then I was usually safe. In other words, no matter what OTHER
precautions you take, don't be afraid to unplug everything! It works!
Dave Oldridge
> Ethernet card contains maybe 2000 volts galvanic isolation.
> How did the transient enter through network card and not enter
> through power supply? Well the network card was connected
> directly to a large lightning rod - called the other
> building. Damage was due to a fundamental violation of
> protection. That ethernet wire must connect (via a protector)
> less than 10 feet to the single point ground before entering
> and leaving each building. Lightning struck one building,
> exited via the ethernet cable, entered computer in second
> building, exited maybe into second building's safety ground,
> and then into earth. Now we have defined the complete circuit
> from cloud to earth.
A bit simplistically and at DC only. Note that both ends of this cable
were thoroughly grounded. But the cable itself was not. Nor did
lightning strike either building. The real lightning rod of record was
an 80 foot steel flagpole in the yard. But the induced surge consists
not only of a DC pulse, but of RF components that range up to AT LEAST
10Ghz. When these get onto even a well-shielded coax, strange things can
happen. At frequencies where the ground points are situated at current
loops, high voltages can still arise at other points on the wiring. And
lightning is very good at producing a whole range of frequencies.
> Again we demonstrate that damage is directly traceable to an
> incoming wire that did not first connect to the building's
> single point earth ground. Again we demonstrated that
> isolation exists and was overwhelmed because the single point
> ground was not provided. Again we have demonstrated damage
> that no plug-in UPS or power strip protector would eliminate.
Wrong. The wire was grounded at the entry point to both buildings.
And a single point ground would have been pretty much impossible (not to
mention irrelevant), since the wiring to reach it would pick up induced
spikes at all sorts of wavelengths.
Granted a UPS was no help here. What the UPS does is signal a problem
with the power and MAY give the software enough time to sequester vital
data to hard drive. For a TV system, it would give you enough time to
terminate a DVD recorder, for example, so that you got an actual DVD and
not a coaster from it.
> Furthermore, transients need not pass through a power
> supply. The adjacent UPS or power strip protector simple
> distributes (shunts) a destructive transient to all wires. IOW
> the plug-in UPS or protector simply gives a destructive
> transient other paths through adjacent electronics. Now the
As I said, unplug it all. That's the only thing that really worked
reliably for me.
> transient has many more paths to enter and damage adjacent
> electronics. And so we have the most common destructive
> path. Incoming on AC electric green wire. Bypasses power
> supply (and any isolation provided by an interactive or
> continuously on-line UPS) to connect directly to motherboard.
> Through motherboard into modem via the PNP transistor that
> drives modem's off hook relay. Into relay coil. Through
> isolation inside that relay to relay wipers. Then out to
> earth ground via phone line.
Yep...which can't happen if the plug is out of the wall and the phone
line is unplugged from the modem.
> Classic example of how modems are damaged. Specific
> components listed because I have diagnosed and repaired this
> so often. One most commonly damaged component in that modem's
> DAA section (more buzz words due to extensive experience and
> underlying theory) is that PNP transistor.
>
> Notice in every case, the problem is created because the
> human did not install and connect to a single point earth
> ground. Also notice that any protection 'claimed' for a UPS
> is simply bypassed. Where is the isolation of an interactive
> UPS when the green wire carries destructive transients
> completely around that UPS? Welcome to concepts that were
> well understood even before WWII.
>
> Can protection be obtained by unplugging everything? Well
> the human is available at most only 1/3rd of the day.
Yes and no. I used my head. If there was lightning in the forecast I
would hang around or unplug before going away. And I used to sleep in
the same building with my computers...AFTER I moved away from that
office.
> Furthermore how is the human suppose to know of every incoming
> transient before it can happen. Human want protection that
> works every time and that is available 24/7. This is called
> 'whole house' protector that costs about $1 per protected
> appliance. You tell me which the human should do? Unplug
> every clock radio, electric clock, smoke detector, bathroom
> and kitchen GFCI, and dimmer switch because he suspects a
> thunderstorm? Or pay $1 to protect each appliance
> constantly? This is not a difficult decision. Do what
> mankind has been doing since 1752 when Ben Franklin
> demonstrated effective protection - and it costs so little.
Obviously, you cannot protect everything. And grounding only helps SOME
things. You cannot use DC logic on lightning--because it isn't DC. It's
DC with all these added RF components.
I'm still doing it here in Chilliwack where thunderstorms are rare. When
one comes along, I yank the plugs from the wall and remove the wire
coming in from the dish. I might lose the LNB (probably not if I took
the wire off that end, too), but it's highly improbable that I'd lose the
TV or any of the computer equipment.
There is NO point in just grounding the equipment and then leaving a wire
connected to a dish on the roof. That's just asking for trouble!
w_tom
numerous and massive outages to their $multi-million switching
computers. Cell phone towers are constantly damaged. 911
operators remove headsets (stop taking calls) during
thunderstorms. And with 25 direct strikes every year to the
Empire State Building, then FM and TV stations are constantly
damaged.
An old story from the early days of Ham radio. They
suffered lightning damage. They even disconnected the antenna
and place that lead inside a mason jar. They still suffered
damage. Then the antenna was earthed. No more damage. Even
isolation from a mason jar was not effective.
You think fuses and switches with millimeter separation will
stop what even miles of sky could not? You think fuses that
take milliseconds to blow will open fast enough to stop the so
destructive microseconds transient? Numbers that you
continuously avoid say you are wrong. These are damning
numbers. Explain the contradiction.
Furthermore how much spacing is recommended for downleads of
lightning rods. Some say as much as 6 feet. Two feet is
considered minimal. This is not due to induced fields from
nearby strikes. This is due to breakdown voltages. So how
does a millimeters fuse or switch stop that breakdown voltage?
How does a flag pole 100 feet away induce a spike but
contacts on a switch only millimeters apart does not? More
damning numbers.
Breakdown voltage. Another number you have avoided. Once
we discuss breakdown voltages, then your isolation techniques
again have no merit.
No numbers are provided for fields rumored to create induced
spikes. Why not? If correct, then those numbers would be
found in the so many IEEE papers. IEEE papers do discuss
induced transients. But your induced spikes are only ghost
stories - not found in those IEEE papers.
We have generations of industry experience, fuses that are
clearly too slow, high reliability locations that use earthing
to not suffer damage from direct strikes, a real explanation
why that struck flag pole can be part of a destructive
circuit, numbers that you don't provide and that say your
speculations are unsupported, figure from the NIST that shows
how bad grounding causes damage, and IEEE papers that
disagree with your conclusions. When will you provide
supporting information? Your speculations are not even
tempered with numbers or responsible sources. When will you
put up electromagnetic field numbers to prove your 'induced'
speculation?
But lets assume your are correct about these induced
transients. Then clearly every neighborhood radio and TV is
damaged when lightning strikes. Clearly every automobile
radio is destroyed. They are not damaged? Correct. Number
of damaged radios? Zero. Where is all this damage from
induced spikes?
Transient protection is about earthing. You claim "it is
NOT a solution for spikes that arrive via antenna leads,
telephone connections (though grounding may help these
somewhat) and network wiring." Where do you think these
principles were applied first - to demonstrate no surge
damage? In broadcast and ham radio stations and in every
telephone switching center. Do you invent this stuff as you
go? Did you even learn the history of transient protection as
was well documented in GE and Westinghouse papers before WWII?
Believe you? How can I? You invent induced spikes that
contradict generation of industry experience. You don't
provide numbers. You even claim a millimeter fuse will blow
fast enough AND provide isolation when miles of sky could
not. You even ignore that 250 volt rating on fuses. 250
volts alone says a fuse could not isolate the destructive
surge. Just another number you avoid. Where are any
supporting facts to validate your 'induced spike'? Even
unplugging has been demonstrated with numbers to be unreliable
protection.
A benchmark in protection is Polyphaser. Their application
notes are considered legendary. Do they discuss their product
line? Do they promote isolation for protection? Of course
not. Polyphaser app notes discuss the most important factor
in transient protection - earthing:
http://www.polyphaser.com/ppc_technical.asp
I know I will not convince you otherwise. You are sure you
have sufficient knowledge - even when numbers contradict your
speculations. Your 'induce spike' theory is no long the
point. You are being exampled as why so many promote
ineffective protection methods - numbers, science concepts,
and generations of experiments and experience all be damned.
Any isolation that will provide sufficient protection is
already inside electronics. Appliances have sufficient
protection that may be overwhelmed if not earthed before that
transient can enter a building. Well proven in high
reliability facilities, demonstrated by the underlying theory,
explained by numbers, and even demonstrated by a dead horse.
But somehow all those facts mean nothing? That is the point.
A first indicator of junk science is no numbers. How does a
computer sit only four feet away from a lightning rod downlead
- and not even reboot? An induced strike would clearly damage
a computer only four feet away - assuming a struck flag pole
100 feet away also creates destructive fields. More damning
numbers. Explain how fields only four feet away are trivial
but fields 100 feet away are so destructive? These induced
strikes are classic urban myth.
w_tom
effective protection that works if the building is steel and
concrete. Other buildings still can have a kludge solution.
But he never came back with information necessary to build -
if necessary - that kludge.
tra...@optonline.net
This is a whopping assumption. The amount of surge protection, if any,
can vary all over the place. A typical home that's built today has
zero for AC surge protection, unless a homeowner specifically request
it. Unless someone has some evidence to the contrary, I don't see why
an average apartment building would be any different. And apartments
come in all varities don't they? Many are nothing more than part of a
two or three family house. And since when is a localized surge and
dropoff from another tenant even a danger? The real danger is
typically caused by something quite different and more severe -
lightning.
Pagan
news:1106626610....@z14g2000cwz.googlegroups.com...
Perhaps, but it's easy to make, because there isn't a damn thing a tenent
can do about it anyway.
> The amount of surge protection, if any,
> can vary all over the place. A typical home that's built today has
> zero for AC surge protection, unless a homeowner specifically request
> it. Unless someone has some evidence to the contrary, I don't see why
> an average apartment building would be any different.
Please define "average apartment building." I've seen many four unit, eight
unit, 24 unit, all the way to 1000 units, and that's just the ones in
Southern CA.
As he had questions about surge protecters, it's likely he's concerned for
his equipment.
> And apartments
> come in all varities don't they? Many are nothing more than part of a
> two or three family house.
The OP described it as a "large multi-unit apartment complex." I don't know
what he considers "large", but it hardly matters. If you have to share a
building with one stranger, that is plenty enough people to make your life
exciting, putting aside all concerns about electricity.
> And since when is a localized surge and
> dropoff from another tenant even a danger?
Since large appliances, faulty appliances, and devices that tend to do wierd
things to local power (welders, for one) can cause surges and dropoffs that
can damage one's gear. Of course, this is unlikely, but it wasn't I who
asked the question, and since it IS possible, there ya go.
> The real danger is
> typically caused by something quite different and more severe -
> lightning.
Seems you are missing the point. If a surge from lightning enters a
dwelling, there ain't squat you can do about it, except hope you don't
become personally involved with the circuit. There's really no way you can
redirect a lighting strike that comes for a visit. It is possible to take
steps to decrease the chance of lighting causing damage or injury outside
the dwelling, that is, unless you live in a fucking apartment, where you
can't do shit.
Pagan
w_tom
as if the transistor did not exist. And we, the public, still
do not demand superior earthing be installed when it is so
inexpensive - when footing are poured.
Although the apartment dweller cannot install as effective
protection, still, even the apartment dweller can 'kludge' a
less than fully effective solution. Defined was one type of
building easily protected. But the OP never returned with
details so that a kludge solution can be proposed.
Again, I continue with the point. An idea that other
electric consumers can cause transient damage is absurd - an
assumption based only upon insufficient technical knowledge
and myths. For example, if
> large appliances, faulty appliances, and devices that
> tend to do wierd things to local power can cause surges
> and dropoffs that can damage one's gear.
then we were all trooping to a hardware store weekly to
replace dimmer switches, clock radios, etc - long before the
PC even existed. I never saw these long store lines because
large appliances even back then did not damage electronic
devices. If appliances are so destructive, then even furnace
controls require repair - often. These rumored sources of
destructive transients are just that - myths. Myths provided
without numbers.
Another myth: nothing can protect from lightning. Lightning
is the primary reason for transient protection. Effective
protection is so well proven that damage is often considered a
human failure. Even apartment dwellers have some (poor)
options - without rewiring the apartment.
I can appreciate why you think nothing can protect from
lightning. You have assumed a struck flag pole 100 feet away
induced spikes on electronics. Yes, if you believe this, then
inexpensive lightning protection is impossible. But again, we
visit locations where effective protection is routinely
installed. If the 'lightning struck' flag pole induced spikes
as claimed, then all those high reliability locations would
also routinely suffer damage. Just another inconsistency.
We know how to protect from lightning. Effective protection
was originally demonstrated by Franklin in 1752. But
installing effective protection is made more difficult by what
I now consider the point of this discussion. So many humans
just know ... and never bothered to first learn the science.
Effective protection is about earthing. Destructive
transients are not generated by household appliances.
Challenged are myths too often promoted by those who know all
about protection - but never first learned the principles nor
provide numbers.
The concept is simple. Effective protection is provided by
earthing. Transients damage cannot be stopped by millimeter
fuses or switches, effectively avoided by human unplugging
appliances, nor provided by a plug-in UPS. All were
erroneously recommended in this discussion.
Effective protection is about shunting a transient to earth
so that internal appliance protection is not overwhelmed.
Understanding those principles starts with science as taught
in elementary school (which means a transient did not enter on
phone line, damage modem, then stop). IOW protection is only
as effective as its most important component - earth ground.
We know this to be false and yet too often promoted by those
who claim to understand protection:
> Look, the only REAL protection from lightning is
> isolation, pure and simple.
We will stop what 3 miles of sky could not? Good luck
trying to prove that claim. Surge protection is only as
effective as its earth ground - the most critical 'system'
component.
Pagan wrote:
> <tra...@optonline.net> wrote in message
> news:1106626610....@z14g2000cwz.googlegroups.com...
>> This is a whopping assumption.
>
> Perhaps, but it's easy to make, because there isn't a damn thing
> a tenent can do about it anyway.
>
>> The amount of surge protection, if any, can vary all over the
>> place. A typical home that's built today has zero for AC surge
>> protection, unless a homeowner specifically request it. Unless
>> someone has some evidence to the contrary, I don't see why an
>> average apartment building would be any different.
>
> Please define "average apartment building." I've seen many four
> unit, eight unit, 24 unit, all the way to 1000 units, and that's
> just the ones in Southern CA.
>
> As he had questions about surge protecters, it's likely he's
> concerned for his equipment.
> ...
> The OP described it as a "large multi-unit apartment complex." I
> don't know what he considers "large", but it hardly matters. If
> you have to share a building with one stranger, that is plenty
> enough people to make your life exciting, putting aside all
> concerns about electricity.
> ...
Dave Oldridge
> If what you post was true, then the telco is suffering
> numerous and massive outages to their $multi-million switching
> computers. Cell phone towers are constantly damaged. 911
> operators remove headsets (stop taking calls) during
> thunderstorms. And with 25 direct strikes every year to the
> Empire State Building, then FM and TV stations are constantly
> damaged.
>
> An old story from the early days of Ham radio. They
> suffered lightning damage. They even disconnected the antenna
> and place that lead inside a mason jar. They still suffered
> damage. Then the antenna was earthed. No more damage. Even
> isolation from a mason jar was not effective.
>
> You think fuses and switches with millimeter separation will
> stop what even miles of sky could not? You think fuses that
Very damn little will take a direct hit and survive. I've only seen one
piece of equipment do that and it it did not emerge unscathed. That was
a Nautel 1KW transmitter on 500Khz that was installed by professional
engineers. The direct hit blew out 3 out of the 4 final stage modules
but left one still working (God alone knows why). But that was a direct
hit to the transmitting tower (which was WELL grounded, as were the leads
coming and going).
> take milliseconds to blow will open fast enough to stop the so
> destructive microseconds transient? Numbers that you
No, I do not and didn't say that. Did you even read what I said. I said
pull the damn plugs out of the wall and pull the network and antenna
leads off the equipment. Not very easy. Not very convenient, but damned
effective for most lightning induced spikes. Direct hits are another
matter entirely, very little will survive one. The strike that blew four
ethernet cards, a modem or two and a monitor on me went through the roof
of a house across the street and literally fried everything the poor man
had. But my equipment was connected at that time (lesson learned,
though).
> continuously avoid say you are wrong. These are damning
> numbers. Explain the contradiction.
> Furthermore how much spacing is recommended for downleads of
> lightning rods. Some say as much as 6 feet. Two feet is
> considered minimal. This is not due to induced fields from
> nearby strikes. This is due to breakdown voltages. So how
> does a millimeters fuse or switch stop that breakdown voltage?
It doesn't. Like I said, very little in the way of actual equipment can
withstand a direct strike. Were talking thousands of amperes with all
kinds of components right up to gigaherz. It's GONNA fry something. But
induced spikes fry a lot of equipment. Whenever there's a direct hit it
puts out a ragged EMP in all directions. With a good radio on 4Mhz, you
can hear these half a world away at night. Nearby they have a lot of
energy (and not just at 4Mhz) and they will go through a fuse or switch
pretty fast, but not through a good solid state clamp big enough to
absorb them. Nor will they pass through a few inches of dry air, which
is what you get by unplugging).
> How does a flag pole 100 feet away induce a spike but
> contacts on a switch only millimeters apart does not? More
> damning numbers.
Contacts on a switch are not carrying several thousand amperes of direct
lightning hit. The pole is, connecting the cloud base to ground.
> Breakdown voltage. Another number you have avoided. Once
> we discuss breakdown voltages, then your isolation techniques
> again have no merit.
Huh? You either didn't read what I said or you don't have a clue about
the different voltages involved. 6 inches of dry air takes a pretty
large voltage to overcome (I don't have my table here at the moment, but
I'd guess in the neighbourhood of 150,000 or more). Yes, a DIRECT hit
will jump that easily, but few induced surges will.
> No numbers are provided for fields rumored to create induced
> spikes. Why not? If correct, then those numbers would be
> found in the so many IEEE papers. IEEE papers do discuss
> induced transients. But your induced spikes are only ghost
> stories - not found in those IEEE papers.
No, they were found on actual wires. Maybe the IEEE has been ignoring
this stuff so long, I should write a paper on it or something. I think
my copy of Kraus is still around here somewhere and I could do most of
the math in this box.
> We have generations of industry experience, fuses that are
> clearly too slow, high reliability locations that use earthing
> to not suffer damage from direct strikes, a real explanation
Your talking to someone who knows otherwise.
> why that struck flag pole can be part of a destructive
> circuit, numbers that you don't provide and that say your
> speculations are unsupported, figure from the NIST that shows
> how bad grounding causes damage, and IEEE papers that
> disagree with your conclusions. When will you provide
Bad grounding may CONTRIBUTE to damage, but NO amount of grounding will
protect most equipment from a direct strike. The problem with our
buildings was not that the cable wasn't grounded but that it was grounded
at both ends and the dipole formed by the buildings just picked energy
out of the ether, whether it hit the flagpole or the hill across the
road. And there were enough frequency components that the ethernet ended
up above ground no matter what we tried. And it was BURIED.
> supporting information? Your speculations are not even
> tempered with numbers or responsible sources. When will you
> put up electromagnetic field numbers to prove your 'induced'
> speculation?
Oh, I think YOU could do the math. Go look up the size in amperes of any
of the many measured lightning strikes and do a little work.
> But lets assume your are correct about these induced
> transients. Then clearly every neighborhood radio and TV is
> damaged when lightning strikes. Clearly every automobile
A surprising lot of them are. Car radios are somewhat protected, partly
because the front end is a long way out of resonance with the antenna.
> radio is destroyed. They are not damaged? Correct. Number
> of damaged radios? Zero. Where is all this damage from
> induced spikes?
You obviously have not worked in radio very much (or maybe you just
didn't work in a lightning prone area). MOST home electronics is not
connected to outdoor antennas at all. It is only lately that we're
seeing satellite dishes on roofs. Back in the days of tube type
electronics, induced voltages had to get pretty high to damage the tube
or its associated circuitry. FETs are totally another story.
> Transient protection is about earthing. You claim "it is
> NOT a solution for spikes that arrive via antenna leads,
> telephone connections (though grounding may help these
> somewhat) and network wiring." Where do you think these
> principles were applied first - to demonstrate no surge
> damage? In broadcast and ham radio stations and in every
> telephone switching center. Do you invent this stuff as you
> go? Did you even learn the history of transient protection as
> was well documented in GE and Westinghouse papers before WWII?
And I've seen just how good it is in the clinch. Yes, GOOD earthing is
not without merit. But it is no guarantee, believe me. All I'm saying
is that, in the typical home installation, especially if you have no
house protection on your power or incoming cable or sat dish or whatever,
you're better off disconnecting these things than you are sitting there
taking a licking.
> Believe you? How can I? You invent induced spikes that
> contradict generation of industry experience. You don't
Well, then talk to MY industry experience. I did radio for 30 years and
I know from antennas and lightning. It's pretty easy to protect against
the induced spikes, but the few direct hits I've seen created a mess.
Now, that said, the gang put in a 300 foot VHF tower near my place after
I retired and it seems to be able to take a direct hit without frying
anything. But VHF is a lot easier to clean up than MF or HF, and wrist-
thick heliax coming from the tower into the building can be heavily
grounded without being damaged by high currents, IF the tower is properly
done. The real problem is not getting the energy from the tower into the
ground, though. That part is pretty easy. It's preventing any from
spilling over onto the coaxes.
> provide numbers. You even claim a millimeter fuse will blow
> fast enough AND provide isolation when miles of sky could
> not. You even ignore that 250 volt rating on fuses. 250
No I don't. You misread me. I claim that it's a lot worse than six
inches of dry air. That's all.
> volts alone says a fuse could not isolate the destructive
> surge. Just another number you avoid. Where are any
> supporting facts to validate your 'induced spike'? Even
> unplugging has been demonstrated with numbers to be unreliable
> protection.
> A benchmark in protection is Polyphaser. Their application
> notes are considered legendary. Do they discuss their product
> line? Do they promote isolation for protection? Of course
> not. Polyphaser app notes discuss the most important factor
> in transient protection - earthing:
> http://www.polyphaser.com/ppc_technical.asp
>
> I know I will not convince you otherwise. You are sure you
> have sufficient knowledge - even when numbers contradict your
> speculations. Your 'induce spike' theory is no long the
> point. You are being exampled as why so many promote
> ineffective protection methods - numbers, science concepts,
> and generations of experiments and experience all be damned.
So what do YOU advise. Should people spend $54,000 grounding a $15,000
home theater system so that it can withstand a direct strike on the
satellite dish (the LNB will probably STILL be toast), or should they put
in reasonable surge protection and pay attention to weather forecasts,
disconnecting the power, antenna and phone or cable connections from
their equipment when lightning threatens?
And please don't bother to answer. You are clearly not reading my posts
anyways.
> Any isolation that will provide sufficient protection is
> already inside electronics. Appliances have sufficient
What electronic part do you have in your equipment that is the equivalent
of 6 inches of dry air? We're talking voltage protection of devices that
will fry from very little over-current here.
> protection that may be overwhelmed if not earthed before that
> transient can enter a building. Well proven in high
> reliability facilities, demonstrated by the underlying theory,
> explained by numbers, and even demonstrated by a dead horse.
> But somehow all those facts mean nothing? That is the point.
You talk a lot about numbers. Go crunch some. Estimate the magnetic
flux from a lightning strike nearby and its effect on voltages at various
spots on conductors in the vicinity. Be sure to include all the
frequency components of the high-amperage spike.
> A first indicator of junk science is no numbers. How does a
Yep.....and you're living proof of that!
> computer sit only four feet away from a lightning rod downlead
> - and not even reboot? An induced strike would clearly damage
That depends on what the computer actually sees on the incoming wiring.
Are you telling me the lightning rod took a direct hit? Induced spikes
in the lightning rod will not add much to the computer's problems. What
will bother the computer is an induced spike on its power lines, network
cables, telephone lines or other external wiring. And I've seen them do
a lot more than reboot.
> a computer only four feet away - assuming a struck flag pole
> 100 feet away also creates destructive fields. More damning
> numbers. Explain how fields only four feet away are trivial
> but fields 100 feet away are so destructive? These induced
> strikes are classic urban myth.
Look BOZO, if your stupid little lightning rod took a DIRECT hit, the
vapour from it would burn the computer.
You really don't crunch those numbers much, DO YOU?
You're talking to someone who DID radio for 30 years and who has seen
more REAL lightning than he wants to.
Maybe you should go and tell your grandmother how to suck eggs or
something.
Leonard Caillouet
"Pagan" <DirtyS...@chonch.com> wrote in message
news:10vbl6m...@corp.supernews.com...
> Seems you are missing the point. If a surge from lightning enters a
> dwelling, there ain't squat you can do about it, except hope you don't
> become personally involved with the circuit. There's really no way you
can
> redirect a lighting strike that comes for a visit. It is possible to take
> steps to decrease the chance of lighting causing damage or injury outside
> the dwelling, that is, unless you live in a fucking apartment, where you
> can't do shit.
>
> Pagan
In spite of what you f-ing believe and what w_tom says, I see units that do
have MOVs in the power supply, the MOV blows, the main fuse blows, and
everything else is ok. The degree to which damage occurs in a lightning
strike and how it distributes is difficult to predict and the assumptions
that know-it-alls make are often proven wrong by experience. Obviously they
do work in many cases. Since most units do not have MOVs on the a.c. input,
or have minimal ones, and since many grounding systems are aged and corroded
or faulty, it seems to make sense to add extra surge suppression at the
equipment. Everyday experience servicing electronics for many years in the
most lightning prone are of the US tells me it is foolish not to have extra
protection. Now are many suppression systems overly hyped and a ripoff?
Surely true. Pay attention to good grounding according to electrical codes,
three way protection, joule ratings, and protect all incoming lines.
Leonard
Leonard Caillouet
"Dave Oldridge" <dold...@leavethisoutshaw.ca> wrote in message
news:Xns95E9FEE0F14E...@24.71.223.159...
> So what do YOU advise. Should people spend $54,000 grounding a $15,000
> home theater system so that it can withstand a direct strike on the
> satellite dish (the LNB will probably STILL be toast), or should they put
> in reasonable surge protection and pay attention to weather forecasts,
> disconnecting the power, antenna and phone or cable connections from
> their equipment when lightning threatens?
We recommend verifying that grounding on the a.c. service is clean and
tight, that all incoming lines are grounded to that point as per codes, and
good quality surge suppression that covers all lines at the home theater
system. Whole house suppression is a good idea, but phone and cable
companies rarely do it.
Direct lightning strikes are likely going to do some damage regardless of
precautions. More common are the many homes nearby that get smaller surges.
These can be protected, IME. We almost never see damage on equipment in our
installations, done by our technicians. My business doubles during storm
season, however, with equipment damaged by surges. Curious that it is
almost never equipment connected to surge suppressors we sell in correctly
installed systems.
Good sense installations don't cost thousands. Again, pay attention to good
grounding, buy surge suppressors with large capacity, three way protection,
and protection for all lines into the system. Get whole house suppression
and suppression on each system within the home. And don't bother with
excessive filtration/conditioning systems unless they are needed for some
specific noise problem, which is rare.
Leonard
tra...@optonline.net
dwelling, there ain't squat you can do about it, except hope you don't
become personally involved with the circuit. "
That's simply not true. A destructive surge of thousands of volts can
come down the power line from a lightning strike that wasn't even near
the building in question. Lightning could hit a overhead line down the
street and still have a resulting nasty surge appear in your home.
That is the more typical case and is far more common than a direct
strike to the building or service entrance. This type of event is
protected against by surge protector which provides a path to ground
for the transient.
As for faulty appliances screwing up power in an apartment building
and needing surge protection, I think Tom had an excellent point. If
that were the case, we's all have lots of experience by now with one
appliance interfering with another wouldn't we? It might happen in
rare cases, but a lightning transient entering via external wires, be
they AC, cable, or phone is far more likely, unless they are protected
correctly.
w_tom
adjacent house. Because the offending home had disconnected
its earth ground, then current left on the cable, entered the
other house cable, passed through TV to obtain earth ground.
The emergency response man from the electric company told me
he borrowed the IR vision equipment from the firemen, and then
followed the hot cable wire inside the walls.
Just another reason why earthing is so critical for all
incoming utility wires. The other guy may be so irresponsible
as to not earth his home. Earthing would protect your home
from his defective appliances.
w_tom
survived direct strikes with no electronic damage on the
protected side - I guess I was totally mistaken so many times.
Dave says so. I guess your telephone switching computer gets
replaced maybe once every 5 years - days without telephone
service - because nothing can protect from direct strikes. I
guess those TV stations atop the World Trade Center that were
struck about 40 times every year were constantly replacing
their equipment. Clearly they are all wrong because Dave
Oldridge knows better?
That again is the point. Dave Oldridge does not understand
the concepts and has experience not tempered by underlying
knowledge. Its called being one's own worst enemy when one
just knows - numbers, well proven principles, and even the
elementary school science lessons be damned. That is the
point made repeatedly. Dave just knows. Therefore 911
emergency operators remove headsets and stop taking calls with
every thunderstorm. Dave just knows nothing can protect them.
Just another in the long list of industry professionals who
say, in essence, that Dave Oldridge is lying:
http://www.harvardrepeater.org/news/lightning.html
> Well I assert, from personal and broadcast experience spanning
> 30 years, that you can design a system that will handle
> *direct lightning strikes* on a routine basis. It takes some
> planning and careful layout, but it's not hard, nor is it
> overly expensive. At WXIA-TV, my other job, we take direct
> lightning strikes nearly every time there's a thunderstorm.
> Our downtime from such strikes is almost non-existant. The
> last time we went down from a strike, it was due to a strike
> on the power company's lines knocking *them* out, ...
> Since my disasterous strike, I've been campaigning vigorously
> to educate amateurs that you *can* avoid damage from direct
> strikes. The belief that there's no protection from direct
> strike damage is *myth*. ...
> The keys to effective lightning protection are surprisingly
> simple, and surprisingly less than obvious. Of course you
> *must* have a single point ground system that eliminates
> all ground loops. And you must present a low *impedance*
> path for the energy to go. That's most generally a low
> *inductance* path rather than just a low ohm DC path.
And then we have this man who also has underlying knowledge
AND experience:
http://scott-inc.com/html/ufer.htm
> In sixteen months, the site has maintained twenty-four hour
> per day operation with ZERO downtime except due to AC power
> failure. With equipment so susceptible to transients, this
> kind of performance is unusual in this region, especially
> on this hill.
Dave make claims even in his latest post that he cannot
document, cannot explain using electrical principles, has no
numbers for, and contradicts what is accomplished repeatedly
in virtually every town as well as on mountains that are
constantly struck. Furthermore, Dave keeps making the same
unsupported claims. Posted in response are reams of numbers,
well proven principles, industry professional testimony,
concepts from IEEE papers, descriptions of how to install
effective protection, and .... well why bother to continue.
Dave Oldridge just knows. Facts be damned.
Dave even claims nothing can protection from thousands of
amps in a direct strike. OK. Go to Home Depot. Read numbers
on boxes. The Intermatic IG1240RC 'whole house' protector is
rated for 50,000 amps. Who is lying? Intermatic or Dave?
Again, Dave makes claims that contradict even those
experiments on a Hoher Peissenberg communication tower in
southern Germany or the IEEE article from van der Laan and van
Deursen entitled "Reliable Protection of Electronics Against
Lightning: Some Practical Applications". Ahhh, but Dave
claims:
> Maybe the IEEE has been ignoring this stuff so long, I
> should write a paper on it or something.
Dave, you are why we have peer review.
Even before WWII, both Westinghouse and GE wrote the papers
that demonstrate effective protection from direct strikes.
Clearly even the IEEE is ignoring the subject because Dave
knows better?
That is the point. Dave examples the too many who recommend
Panamax, APC, Tripplite, Monster, and Belkin protectors and
UPSes only because they *know* - facts be damned. Dave so
knows that he does not even try to challenge any numbers or
any professional paper. He just knows they are wrong. He is
the classic example of an urban myth purveyor. He just
knows. Facts, numbers, and basic principles of electricity be
damned.
Yes Dave, I did read everything you posted which is why I
say you never posted a single useful number and did not cite
valid electrical principles. You still claim a fuse that
takes millisecond to blow will stop a destructive transient
that completes in microseconds. At least you are no longer
trying to claim a surge enters on a phone line, damaged a
modem, then stopped. At least you stopped denying those
'elementary school' science lessons on how electricity works.
So we are making progress.
> ....
w_tom
cable connections make a connection to what is the single
point earth ground. A requirement first for human safety also
provides the transistor safety. My cable company recently
retrained their installers after AT&T sold them off. Now
connections to earth ground must be shorter than the
connection to any TVs or cable modem. This cable company
requirement is in beyond what is required for human safety.
Yes, once installers were so poorly trained as to even install
interior grade cable outside and underground. Then blame the
degraded service on anything but untrained installers. That
has changed. Cable company is now installing effective
protection as baby Bells have been installing for decades.
Both are required by the National Electrical Code and by the
FCC to earth their incoming wires.
Leonard Caillouet
> The National Electrical Code demands that both phone and
> cable connections make a connection to what is the single
> point earth ground. A requirement first for human safety also
> provides the transistor safety. My cable company recently
> retrained their installers after AT&T sold them off. Now
> connections to earth ground must be shorter than the
> connection to any TVs or cable modem. This cable company
> requirement is in beyond what is required for human safety.
> Yes, once installers were so poorly trained as to even install
> interior grade cable outside and underground. Then blame the
> degraded service on anything but untrained installers. That
> has changed. Cable company is now installing effective
> protection as baby Bells have been installing for decades.
> Both are required by the National Electrical Code and by the
> FCC to earth their incoming wires.
....and your point that has some meaningfulness to the readers of this group
is what?
There are still many cable installers who do not understand much at all
about the importance of grounding, even more satellite antenna installers,
and many cable systems that are many years old that are poorly grounded, if
at all. Your willingness to assume that problems don't exist in the rest of
the world because your cable company does its job well or because someone
defined some standard belies a condescending attitude that does little more
than confuse many readers in this group.
The fact is that there are many installations that are not well grounded,
and many that need attention due to years of being ignored. Consumers,
installers, contractors, and service technicians need to be more well
educated on the matter. Much of what you post is correct factually, but
applied inappropriately.
Leonard
42
> We will stop what 3 miles of sky could not? Good luck
> trying to prove that claim. Surge protection is only as
> effective as its earth ground - the most critical 'system'
> component.
A brief google groups of your name 'w_tom' along with the words "surge
protector" brings up about a 5000 posts on the subject going back 5
years, spanning more groups than I care to ennumerate.
You've been making this argument for a very long time, anywhere you can.
Whether you are right or wrong Nobody here is going to affect your
position.
In my own experience, I beleive inexpensive surge protectors have
prevented damage to some of my equipment, and I think they are a useful
and worthwhile investment. I agree completely that Monster et al
products are grossly overpriced and marketed under a haze of myth,
superstition, and outright lies. And I even agree that by and large your
assement of the effectiveness of 'surge protectors' against a direct
lightning strike is accurate.
However, I remain unconvinced that they are completely useless. Not
every surge that hits my equipment has the potential to leap miles of
sky. And even if the internals of the equipment -should- be able to
handle it as well as the surge device does... I'm unconvinced that they
always do. If nothing else, frying a $20 replaceable-by-me 'surge
protector' instead of $60+ worth of electronics repaired by a technician
at $90.00+/hr seems like a good tradeoff... and hey I needed a power bar
anyway.
Dave Oldridge
> Well I guess those so many designs I built decades ago that
> survived direct strikes with no electronic damage on the
> protected side - I guess I was totally mistaken so many times.
Very few DIRECT strikes are ever experienced. I've only seen two in over
30 years.
> Dave says so. I guess your telephone switching computer gets
> replaced maybe once every 5 years - days without telephone
> service - because nothing can protect from direct strikes. I
> guess those TV stations atop the World Trade Center that were
> struck about 40 times every year were constantly replacing
> their equipment. Clearly they are all wrong because Dave
> Oldridge knows better?
That equipment HAD to be very well protected. But could you do the same
for may apartment at any price that's affordable?
No why don't you go and preach in one of the religious echoes.
Bored now.
Marty
alt.tv.tech.hdtv, I think I thought I saw this post from w_tom
<w_t...@hotmail.com>:
> . . .
Wow! With that much verbiage, you must be right. But my experience is that
the more someone talks, the less they know, and try to cover up their lack
of knowledge by overwhelming a person with so much talk that the person just
gives up.
Good job!
--
Marty
"Those are my principles, and if you don't like them...
well, I have others." - Groucho Marx
Kalman Rubinson
wrote:
>There are still many cable installers who do not understand much at all
>about the importance of grounding, even more satellite antenna installers,
>and many cable systems that are many years old that are poorly grounded, if
>at all. Your willingness to assume that problems don't exist in the rest of
>the world because your cable company does its job well or because someone
>defined some standard belies a condescending attitude that does little more
>than confuse many readers in this group.
Exactly. I have been suffering with ground loop hum from the cable
input to my system for years and compensated with a 'ground loop
interrupter" until recently. When the cable service tech responded to
another (related) problem, I told him about the poor grounding
practices so common in his industry and suggested that they relocate a
substantial ground at the main house ground. He was surprised but
accomodating. It took him less than 15 minutes to correct the
situation.
Kal
w_tom
years. Just another reason why unplugging is so ineffective
AND why we spend a massive $1 per protected appliance - so
that one transient will not damage everything. Apparently
damage is acceptable to you. Good enough. But don't impose
your low standards on others. Others can spend $1 instead of
your $15 or $50 to obtain real protection.
A surge protector is only as effective as its earth ground.
No earth ground means no effective protection. Protection is
about transients that occur typically once every eight years.
Number that varies with geographical location and underlying
geology.
w_tom
protectors. But without a short, direct, and independent
shunt to earth ground, then effective protection still does
not exist. Yes there are still installers who don't
understand the importance of earthing. I recently shared
coffee with two who were reeducated by the company, but did
not understand the whys? One kept saying, "Is that why they
said that."
Do we fix that installation problem with ineffective and
grossly overpriced protectors? Best protection a homeowner
can have is knowledge about single point earthing. No plug-in
protector is going to cure a missing earth ground.
If the homeowner wants protection, then he gets a cable
company to install the cable to meet National Electrical Code
standards. Cable company knows they must meet those
requirements. But if a homeowner is naive, the cable company
may just take shortcuts. Solve the problem. Get the cable
properly earthed as even required by code.
w_tom
only as effective as its earth ground. No earth ground means
w_tom
protector. Why was the adjacent appliance not damaged? After
all, same transient hit both simultaneously. Yes, protector
does not sit between transient and appliance. Transient hits
both simultaneously. Reality: appliance protected itself. Any
protector that fried provides no effective protection.
Effective protectors don't fry. Even worse, the protector can
provide more destructive paths through an adjacent appliance.
Where is the protection? Frying - which means it is not
effective.
Over so many years, I repeatedly ask the same question.
Post manufacturer's numerical specs for protection from a
typically destructive transient. No one has done so. The
closest one came:
> SURGE PROTECTION AND FILTERING
> Normal mode clamping response time 0 ns, instantaneous
> Normal mode surge voltage let through <5% of test peak
> voltage when subjected to IEEE 587 Cat. A 6kVA test
> Normal mode noise suppression Full time EMI/RFI filtering
> Modem/10Base-T/100Base-Tx network cable port single line
> (2 wire, RJ11) or network (UTP, RJ45) compatible jacks
Damning fact they hope we don't notice. Destructive
transients are longitudinal mode. Manufacture avoids
discussing longitudinal mode and discussing earth ground so
that we will make erroneous assumptions.
Find specs today that even mention normal mode. With even
less facts, then you will not ask, "What about longitudinal
mode?" Better to just claim generic transient protection and
hope the naive will make blanket assumptions.
An adjacent $20 protector does nothing for you while
enriching the manufacturer. It does even less if it fries.
Electronics already has sufficient protection (as required by
industry standards) IF a destructive transient is earthed.
And again, the plug-in protector can even contribute to damage
of an adjacent appliance. A plug-in manufacturer will starve
you of facts hoping you will 'wish' it does something useful.
No mention of longitudinal mode surge protection even though
destructive transients are longitudinal mode. Forgets to
mention that a plug-in protector can provide a transient with
more paths through adjacent appliance. What you don't know
won't hurt .... them.
Dave Oldridge
> Destructive transient occurs typically once every eight
> years. Just another reason why unplugging is so ineffective
> AND why we spend a massive $1 per protected appliance - so
> that one transient will not damage everything. Apparently
> damage is acceptable to you. Good enough. But don't impose
> your low standards on others. Others can spend $1 instead of
> your $15 or $50 to obtain real protection.
>
> A surge protector is only as effective as its earth ground.
That's nice. Today, I live 20 feet above ground level here. And I'm not
permitted to put things over the balcony and into the ground, so we're
stuck using existing wiring and/or copper pipe. A 20-foot ground wire
will have all kinds of voltage at the upper end, anyway. Not DC voltage,
to be sure, but voltage that is quite capable of spiking semiconductors.
> No earth ground means no effective protection. Protection is
> about transients that occur typically once every eight years.
> Number that varies with geographical location and underlying
> geology.
Yep.....but earth ground isn't always effective protection. That
ethernet cable I told you about had one of those (and I mean with a
ground rod driven 8 feet into the dirt) at each end. It didn't help a
bit. Why? Because induction does not only take place at DC.
Now maybe YOU could have engineered it differently. The professionals
who put it in didn't and I could not see anything wrong with what they
did. Of course today, I'd just do it in a non-conducting optical fiber
and be done with it.
w_tom
anyway. You even think destructive transients are DC.
Destructive microsecond transients are not DC. Just another
little fact that one with basic electrical knowledge should
have known. That is the point. You just know; technical
facts be damned.
BTW, if those ethernet cable installers had to install 8
foot ground rods, then the installation was defective. That
coax was not connected to an existing single point ground.
That glaring defect should have been obvious before you even
posted. No single point ground explains network damage.
Demonstrated again is the primary point - why some will
recommend ineffective, undersized, and overpriced protectors.
Dave Oldridge
> No problem, Dave. Nothing posted here was for your benefit
> anyway. You even think destructive transients are DC.
You even think you can read for meaning. Why should I believe anything
you say you have read, when you cannot even read my posts for meaning.
> Destructive microsecond transients are not DC. Just another
> little fact that one with basic electrical knowledge should
> have known. That is the point. You just know; technical
> facts be damned.
Just another stupid misreading of what I actually posted. If you can't
read what I write, then don't even bother to reply. You're not worth
correcting.
> BTW, if those ethernet cable installers had to install 8
> foot ground rods, then the installation was defective. That
> coax was not connected to an existing single point ground.
Therein is the problem. How do you get a SINGLE POINT GROUND when the
electrical systems in both buildings are grounded separately? But the
fact is, even a single point ground will not help you. I did have JUST
such a ground on an antenna system once. The lead was exactly 16 feet
long and led directly to a single six-foot rod that was pounded into
salt-water-soaked sand a few hundred yards into a sand bar in the
Atlantic ocean. Applying RF to the system resulted in 5000 volts at the
top of the ground lead at 14mhz. Not enough to fry anything, but that
was just from the internal workings of the system. I got a BETTER RF
ground by simply removing the wire from the rod and insulating it (though
at the expense of more radiation from the upper end of the ground wire).
And, believe me, the ELECTRICAL ground for the equipment was different
from the RF ground. The point is, lightning is not DC. It's not even
CLOSE. But YOU had to misrepresent what I wrote and then yell about it.
Don't even bother to reply. Just go take a remedial reading course until
you can actually read what I post.
mb
question and I apprecitate everyone's time, effort and input.
My complex is in northwest Florida and has 230 units averaging 1200 sq.
ft. I think the construction would fall into the "steel & concrete"
category, but I'm not sure. Interior studding is metal of some kind.
Compared to south Florida, this area isn't the lightning capitol of the
world, but we get our fair share, and judging from sound and flash
alone, we've had a few close calls, but I've never had anything damaged
using inexpensive power strips.
Having said this, I've never paid $1500 for a television set before, so
therein lies my concern. As always, thanks.
mb
Pagan
news:MPG.1c63623db...@news.east.cox.net...
You may have noticed, I've pretty much bowed out of this discussion. I
simply don't have the background, time, or energy to endlessly argue with
everybody, especially those who don't really understand your position and/or
offer huge technical discussions while leaving out anything resembling a
solution.
I'd say your best protection above all others is a good warranty, the kind
most folks (including me) feel is a rip-off in most cases. Some stores
offer 30 days or so after you buy to purchase their in-house warranty, and
it may be a good idea if the company, such as Best Buy or Sears, is going to
be around for a while.
You also may want to review or insurance or contact your agent.
If it were me, I'd do the above, then buy a fairly cheap surge protector, or
even better a UPS, or both, and if a hurricane or other huge storm comes
calling, unplug your gear, including the antenna/cable/sat leads. If your
paranoid and/or have the bucks, one of those Panamax suppressors might be
better. The other expensive surge protectors and line conditioners,
especially ones with their own warranties, are pure rip-offs.
Despite what some folks say about a UPS, it certainly can't hurt, and it
sure is handy when the power goes out and you have a cordless phone plugged
in, not to mention a DVR or TIVO.
And for all those good people who are going to follow this post with a
million-and-one reasons why nothing I mentioned works, then back up your
claims and OFFER SOME SOLUTIONS THAT DO WORK. :-)
Pagan
S.P.
(I have 3) meet the house will result in a much better ground than the
pathetic way they strap it to a water spigot that has to run 60 feet through
the house, and then through the water meter, before being grounded?
Mr Fixit
<schmar...@yahooooo.com> writes:
Perhaps. Any "ground" is better than none and it is as much for your own
safety as anything else. The goal here is in being able to provide some
basic level of protection from electrocution while at the same time
realizing that nothing will protect your equipment from a direct lightning
hit. (i.e., one which hits a tree in your yard or an antenna on your roof
or the pole from which your power/phone/cable service comes)
Inarguably the most dangerous "ground" is one which has been stupidly
attached to a natural gas pipe. I've seen it several times...
Ordinarily the best "ground" is the ground rod driven in by the power
company at the electrical service entrance point. These are (normally) 8
feet long and is the point at which everything (power, phone, cable, etc)
**should** be grounded. Anytime you have multiple grounding points you
have the potential of creating a "ground loop" which can be the source of
some really strange problems. A cold water pipe "ground" can be a very
good grounding point only if it's copper or iron pipe and a grounding
strap is in place around the meter. Since local water distribution
companies have been using the much cheaper PVC pipe for the last several
decades, a water pipe ground may very well -not- be true "ground".
Cable TV and phone companies (and sat-tv professional installers) will
drive their own ground rods in usually only when there's no convenient or
obvious ground connection available at their entrance point. Just as a
point of interest, CATV/Phone company ground rods are typically only 4~6
feet long and much smaller diameter than the one installed by the power
company.
Greywolf
news:ie9t41l8bvih6lhac...@4ax.com...
5ft of pipe run to the water main entrance to the building it is a good
ground. You check with your local building department to see if it's a code
violation though. Some areas don't permit water pipe grounding. If a
separate rod is sunk, it must be bonded to the main building ground system
with at least a 6 guage copper wire.
Pat
Phil Ross
when I had my house re-piped with copper (from steel), they had to bring the
grounding up to code. This involved strapping the hot water, cold water, gas
line, ground rod, and meter box all together in one continuous connection.
Made lots of sense to me in that it definitely minimized the ground loop
problem, but it sure made it interesting for the plumber to get it all
connected that way. I did have to drive my own separate ground rod for my
chimney mounted antenna, as it wasn't practical to tap into the existing
ground system because of its location.
"Greywolf" <greywolfin45@*spamisbad*sbcglobal.net> wrote in message
news:5By3e.28291$hU7....@newssvr33.news.prodigy.com...
Greywolf
news:rIz3e.11699$zl....@newssvr13.news.prodigy.com...
>A lot of what can be done is dependant on local codes. I know in my area,
>when I had my house re-piped with copper (from steel), they had to bring
>the grounding up to code. This involved strapping the hot water, cold
>water, gas line, ground rod, and meter box all together in one continuous
>connection. Made lots of sense to me in that it definitely minimized the
>ground loop problem, but it sure made it interesting for the plumber to get
>it all connected that way. I did have to drive my own separate ground rod
>for my chimney mounted antenna, as it wasn't practical to tap into the
>existing ground system because of its location.
If you don't bond that separate rod to the main building ground, you have a
code violation and a possibility of ground loop problems. From
http://www.cinergy.com/surge/ttip08.htm
The 1993 National Electric Code sets the requirements for bonding the
communication, radio, and television antenna and CATV grounds to the power
ground in Articles 800-40d, 810-21j and 820-40d. The code requires a minimum
No. 6 copper bonding conductor between these ground electrodes and the power
grounding electrode, where separate electrodes are used. Please see these
articles and Article 250 of the National Electric Code for further detail on
the proper grounding of low voltage electrical systems.
Pat
S.P.
Hmmm. In my own case, several years ago I had a direct strike to a tree on
which the telephone wires were run. You can see how the peeled bark and
dead wood end at the point where the phone wires grounded the strike through
my computers and phones. Much electronic damage was done. Surge
suppressing power strips were laughed at by the strike because it entered
through the modems and spread through the Ethernet wires.
My cable wires hit the house and are grounded to the external spigot on the
furthest part of the house away from where the electric wires and lead water
pipe enter. The electric panel is grounded through the water pipe after the
water meter. I have to check and make sure there is a strap bridging the
meter. The telephone wires are grounded with a wire from the external 6
pair box to a spigot on that side of the house. The cable wires, though,
ground through about a 70 foot run of 1/2 inch copper water pipe. It sounds
like if I put a real grounding spike on the far side of the house for the
cables it might cause a ground loop, unless I run a 6 gauge copper wire
parallel to the water pipe all the way to the lead pipe ground. Am I wrong
to think this?
Greywolf
news:Rb6dnWUcjfF...@giganews.com...
that somebody in the future may replace part of the pipe with plastic and
not even think about the electrical consequences. That's why it's against
code. If you sink another rod, it will need to be connected to the main
building ground with a 6ga wire. If you don't sink a new rod, you can use a
10ga copper wire from the cableTV coax entry point to the main building
ground. Why go to the extra expense and work of a separate rod and heavier
wire?
Pat
S.P.
> that somebody in the future may replace part of the pipe with plastic and
> not even think about the electrical consequences. That's why it's against
> code. If you sink another rod, it will need to be connected to the main
> building ground with a 6ga wire. If you don't sink a new rod, you can use
> a 10ga copper wire from the cableTV coax entry point to the main building
> ground. Why go to the extra expense and work of a separate rod and heavier
> wire?
As long as the 70 foot copper pipe is good enough to ground the cable lines,
I feel better. Thanks. I still have to check for the meter bridge and that
the connections are tight.