Surge protectors in series
Caesar Romano
surge protection available at the down-stream protector approximately
equal to the sum of the two individual protections??
Bryce
By 'surge protector', do you mean something like plug strips with
MOV peak voltage limiting? If so, the upstream device will limit
an overvoltage transient and the downstream device sees normal
waveform and provides added protection only if the upstream
device fails. Actually, the varistors don't provide an absolute
clamp at their trigger voltage, but the downstream guy will do
very little protecting.
If you're referring to connecting two MOV's in series across the
line, then the overvoltage clamping will begin when line voltage
reaches the sum of the individual MOV clamp voltages. The same
transient current will flow through each MOV, and each will
dissipate part of the transient (as heat). If they have the same
clamp voltage, then each MOV absorbs half of the energy.
RickM...@nowhere.com
On Sun, 03 May 2009 15:23:18 -0500, Caesar Romano <Sp...@uce.gov>
wrote:
E Z Peaces
I haven't thought of it that way. I suppose it's possible, depending on
how a particular protector circuit functions.
I have a protector at my service entrance. When lightning struck my
house, I had perhaps $1000 worth of damage to electronics in various
rooms, but none to my my computer/telephone equipment, which was on a
plug-in protector. Because the surge didn't come in on the line, it
made a big difference to have that equipment plugged directly into a
protector. It's possible that my computer would have been wrecked if
the whole-house protector hadn't absorbed some of the energy.
I have twelve items plugged in at my computer desk. A surge protector
is plugged in at the wall. That feeds a lamp, the phone, and another
surge protector.
The second protector feeds my computer stuff and a third protector,
which feeds my audio/video stuff. If the a/v stuff were connected to a
cable or outdoor antenna, this might be unwise.
One reason to use three protectors is to be able to leave my computer
stuff and my audio stuff switched off, for added protection, while still
using my phone and lamp. The second protector could save my computer
stuff in the event that the first protector fails and lets something
through.
ransley
I had a lightning strike and had Tripp Light units, I asked that
question to their tech support and they said yes. My Tripp light units
are also wired in such a way with added Movs for each outlet so that
on a 6 plug unit the outlet furthest from the power plug has greater
protection. But lightning can come in anywhere, 120v outlets only
cover part of your problem.
mm
wrote:
You don't finish, but aren't you saying that the voltage that gets to
the appliance can reach twice the voltage with only one MOV across the
line, that it's much worse, much less, practically no protection with
two? I don't know enough to know, but that sounds conceivable and
sounds like the logical next sentence to what you wrote.
bud--
Outlet strips are not intended by anyone, including UL, to be connected
in series.
Which protector does the protecting depends on which MOV clamps at a
lower voltage. Voltage ratings, like 330V, are UL categories and cover a
wide range. Even MOVs with the same part number that are not from the
same batch would not likely have identical clamp characteristics. The
upstream or downstream protector may initially do the clamping or it may
be partially or evenly shared.
You would probably get a combined Joule rating equal to the sum of the
individual ratings. If the clamping was actually evenly shared the
combined cumulative rating would be higher than the sum of the
individual ratings.
IMHO loads should only be connected to the downstream protector.
I recommend not connecting in series. Suppressors with very high ratings
are readily available at relatively low cost.
And all interconnected equipment needs to be connected to the same
plug-in suppressor, or interconnecting wires need to go through the
suppressor. External connections, like phone, also need to go through
the suppressor. Connecting all wiring through the suppressor prevents
damaging voltages between power and signal wires.
--
bud--
ransley
Tell that to Tripp Lite, they sell one of the best units made. In fact
im fairly certain they were the first to offer a warranty against
lightning damage.
Bryce
The peak let-thru voltage will be the sum of the series-connected MOV
clamp voltages (a bit higher actually). They are manufactured in several
clamp voltage ratings. Using a series-connected pair would probably
happen only if designing protection for an unusual line voltage or
to make do with what is in the junk box. Using two series-connected
MOV's, each intended for 120VAC to protect a 120VAC line would be a
bad idea. Using the same pair to protect a 240VAC line would be better.
By the way, parallel connection of two or more MOV's is a bad idea.
If they have different clamp voltages, the first to begin conducting
does all the work. Even two MOV's of the same rating will have
slightly different characteristics and won't play well together.
for protection of a 120VAC line
bud--
You aren't specific about which of the many things I said I should tell
to Tripp Lite.
I presume it is that suppressors shouldn't be connected in series. From
the UL White Book:
"Relocatable power taps [power strips, which plug-in suppressors are a
variation of] are not intended to be series connected (daisy chained) to
other relocatable power taps or to extension cords."
--
bud--
westom
> If twosurgeprotectorsare connected in series, is the amount of
>surgeprotectionavailable at the down-stream protector approximately
> equal to the sum of the two individual protections??
You assumed protectors somehow stop or absorb surges. They don't.
Do you really think that protector will stop what three miles of sky
could not?.
A surge first creates a path from cloud to earthborne charges. Then
surge current - electricity -flows simultaneously and equally through
everything in that path. Effective protectors don't try to stop or
absorb that energy. One dffective protector connects a surge to earth
- as the NIST says:
> You cannot really suppress a surge altogether, nor
> "arrest" it. What these protective devices do is
> neither suppress nor arrest a surge, but simply
> divert it to ground, where it can do no harm.
Where does surge energy get harmlessly absorbed? In earth. A
protector is only a connecting device to protection - earth.
Protector and protection are two separate items. A protector located
too far from protection (earth ground) may divert that surge
destructively in other paths inside a building.
E Z Peaces describes a 'whole house' protector. But also describes
a protector apparently with insufficient earthing. One 'whole house'
protector means the surge does not even enter the building; need not
seek earth ground through a computer or other appliances. Again,
first the path from cloud to earth is created. In his case, that
connection to earth was through some appliances - destructively.
A surge that does not enter the building does not seek earth - which
is what every telco everywhere in the world does. Effective earthing
making the original question - connecting protectors in series -
irrelevant. Your telco connected to overhead wires all over town may
suffer 100 surges during each thunderstorm. How often how has your
town been without phone service for four days while they replace their
computer? Telcos don't daiychain protectors. Telcos locate every
protector where each wire enters the building - and making the
shortest possible connection to earth.
Where does surge energy get dissipated harmlessly? In earth.
What a protector connects surges to - where surge energy gets
absorbed - is surge protection - earth ground. Every wire inside
every incoming utility cable connects short (ie 'less than 10 feet')
to earth either using wire (ie cable TV, satellite dish) or via a
'whole house' protector (AC electric, telephone).
Not just any earth ground. All must make a short connection to the
same earth ground electrode.
A protector is only as effective as its earth ground. Where do your
daisy chained (in series)protectors make that "low impedance"
connection to earth? Why do commercial broadcast stations and ham
radio operators routinely suffer direct lightning strikes and never
have damage? Why do telcos not use your plug-in protectors? They
need protection. Protectors connect as short as possible to earth so
that surges need not enter a building. Never damage that telco
switching computer. Nobody will stop or absorb what three miles of
sky could not.
bud will now reply with nasty and insulting comments because he is
paid to do so.
Caesar Romano
wrote Re Re: Surge protectors in series:
> bud will now reply with nasty and insulting comments because he is
>paid to do so.
Who is Bud and who pays him?
sa...@dog.com
Anybody who follows Westom's advice or believes his idiocy is a prime
candidate for the Darwin Awards. Westom is a long time usenet kook who
likes to sprinkle just enough truth in his nonsense to fool people
into doing things that could kill them.
He has changed his usenet identity once again to try and escape from
his past. He used to post as w_tom.
E Z Peaces
Distribution Units. It says they, too, are not intended to be daisy
chained.
It also says they are not intended to be used as Relocatable Power Taps.
I wonder what it would hurt. I'm sure it doesn't mean it's unsafe to
use a surge protector as a power strip. I think it means that there
could be an application were a power strip would be okay but not a surge
protector.
I wonder if they say daisy chaining is not intended because for some
users, too many outlets could mean too many amps.
ransley
>
> - Show quoted text -
Again tell that to Tripp Lite. Some of Trips units with multiple
outlets have increased protection for each outlet as you move away
from the power cord, daisy chaining is only like a strip with
additional outlets. Stick your UL book and learn, call Tripp, mr UL
book.
ransley
>
> - Show quoted text -
You know UL, they gotta keep folks "safe" [from themselves], 1 Trip
unit will do the job it was designed for, if you want safe, what I do
is unplug when storms might be comming and I amd leaving. No surge
protector can protect all that lightning can dish out on a big direct
hit. I got hit bad once it was so strong it lit flourescent lights
that were shut off 3 stories below where it came in when I was in the
kitchen. In the attic track light bulbs were even loosened in the
sockets that worked when screwed back in. It was so strong insurance
pros thought it was a Plasma going through the room since circuits
affected were not near the strike and the electronics damages the ins
covered it cost over 20,000 to the insurance co. There wasnt even ANY
entry point or exterior damage, just fire in one corner box and
equipment fried 50 ft away. It must have been Plasma. A friend had
ball lightning roll-float through his large room and do no damage, I
guess thats Plasma. Lightning is scary stuff. Unplug for 100% saftey,
its less of a hassle than a repair, and you know your stuff is safe.
Im in a place hit 3 times already, and nows the storm season.
westom
> Who is Bud and who pays him?
It will become obvious. Meanwhile, surges are electrical
connections from cloud to earth. First a path forms. Then electric
current flows simultaneously through everything in that path. If
anything attempts to stop that current, then voltage increases as high
as necessary to blow through that obstruction.
Surge protectors do not stop and do not absorb surges. An appliance
is connected directly to AC mains if using no power strip, one power
strip or five power strips in series. Doubt it? Then break one
open. Connection to AC mains is electrically direct. Nothing inside
to obstruct a surge.
Protection means the surge does not enter a building. Protection
means a surge finds earth ground before entering the building. It was
done that way even 100 years ago and is still installed in any
facility that can never suffer damage.
Tony Hwang
Never? Only on theory. On a direct mega hit nothing survives. I
witnessed it first hand years ago.
E Z Peaces
>
>
> You know UL, they gotta keep folks "safe" [from themselves], 1 Trip
> unit will do the job it was designed for, if you want safe, what I do
> is unplug when storms might be comming and I amd leaving. No surge
> protector can protect all that lightning can dish out on a big direct
> hit. I got hit bad once it was so strong it lit flourescent lights
> that were shut off 3 stories below where it came in when I was in the
> kitchen. In the attic track light bulbs were even loosened in the
> sockets that worked when screwed back in. It was so strong insurance
> pros thought it was a Plasma going through the room since circuits
> affected were not near the strike and the electronics damages the ins
> covered it cost over 20,000 to the insurance co. There wasnt even ANY
> entry point or exterior damage, just fire in one corner box and
> equipment fried 50 ft away. It must have been Plasma. A friend had
> ball lightning roll-float through his large room and do no damage, I
> guess thats Plasma. Lightning is scary stuff. Unplug for 100% saftey,
> its less of a hassle than a repair, and you know your stuff is safe.
> Im in a place hit 3 times already, and nows the storm season.
My strike blew masonry from two chimneys as far as 100 feet. It wiped
out three stereo receivers in three rooms. One wasn't plugged in or
attached to anything but speakers.
It amazed me that so many items that were plugged in and running were
apparently not damaged.
bud--
> outlets have increased protection for each outlet as you move away
> from the power cord, daisy chaining is only like a strip with
> additional outlets. Stick your UL book and learn, call Tripp, mr UL
> book.
It is refreshing to know that a phone tech at Tripp Lite is smarter that UL.
(Incidently I like Tripp Lite as a brand.)
Results may not be predictable when using 2 suppressors in series. Take
the example in the IEEE guide
<http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf>
starting pdf page 40. There is as surge coming in on the cable service.
Because the �ground� wire from the cable entry block to the system
ground at the power service is far too long (30 feet) there is 10,000V
between the power ground and the cable ground. That appears at TVs
connected to both power and cable. The example shows how a plug-in
suppressor protects connected equipment.
Now use 2 suppressors connected in series with the 2nd connected to the
TV and the cable going through the 2nd. There will be a current through
cable sheath and power ground wire which lifts the ground at the
suppressors away from the ground at the power service (as is clearly
indicated in the IEEE example). That lifts the ground at the suppressors
from the hot and neutral so the MOVs will limit the voltage H-G, N-G. If
the only MOVs that conduct are in the 1st suppressor you will have the
ground wire in the line cord to the 2nd suppressor (maybe 6 feet)
separating the power ground reference and the cable ground reference.
The voltage drop over 6 feet of the ground wire from the cable entry
ground block to the power service is 2,000V. It will be far lower in the
line cord but will add to the difference in voltage between the power
and cable wires going to the TV. Is that a problem? Who knows - but I
would rather not run the science project.
Multiple MOVs in a single suppressor do not have 6 feet between them.
Since suppressors with high ratings are readily and cheaply available I
don�t see a good reason to connect suppressors is series (except maybe
to connect a UPS with relatively low ratings downstream from a high
rated plug-in suppressor).
--
bud--
tra...@optonline.net
Actually, even whole house surge protectors deal with the surge after
it has entered the building. They are typically installed in the
main panel, which in most cases is inside the building.
And if the only possible way of dealing with surges is an earth
ground, how is it that aircraft have surge protection which deals with
static discharge and lightning strikes?
bud--
> On May 3, 4:23 pm, Caesar Romano <S...@uce.gov> wrote:
>> If twosurgeprotectorsare connected in series, is the amount of
>> surgeprotectionavailable at the down-stream protector approximately
>> equal to the sum of the two individual protections??
The best information on surges and surge protection I have seen is at:
<http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf>
- "How to protect your house and its contents from lightning: IEEE guide
for surge protection of equipment connected to AC power and
communication circuits" published by the IEEE in 2005 (the IEEE is the
major organization of electrical and electronic engineers in the US).
And also:
<http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf>
- "NIST recommended practice guide: Surges Happen!: how to protect the
appliances in your home" published by the US National Institute of
Standards and Technology in 2001
The IEEE guide is aimed at those with some technical background. The
NIST guide is aimed at the unwashed masses
> You assumed protectors somehow stop or absorb surges. They don't.
> Do you really think that protector will stop what three miles of sky
> could not?.
If w had minimal ability to read and think he could read in the IEEE
guide how plug-in suppressors work - clamping (limiting) the voltage on
all wires (signal and power) to the common ground at the suppressor.
Plug-in suppressors do not work primarily by earthing (or stopping or
absorbing). The guide explains earthing occurs elsewhere. (Read the
guide starting pdf page 40).
> E Z Peaces describes a 'whole house' protector. But also describes
> a protector apparently with insufficient earthing.
EZ Peaces appears to describe a direct lightning strike to a house. The
only reliable protection is lightning rods.
> A protector is only as effective as its earth ground.
w has a religious belief (immune from challenge) that surge protection
must directly use earthing. Thus in his view plug-in suppressors (which
are not well earthed) can not possibly work. Unfortunately for w, the
IEEE guide clearly explains how plug-in suppressors work - primarily by
clamping, not earthing. Because that violates w's religious belief he
apparently can't read it - just like he can�t read any other source that
says plug-in suppressors are effective.
Because w is evangelical in his religious belief in earthing he trolls
google-groups for "surge" to save the world from the evils of plug-in
suppressors. He is currently is spreading his drivel in another current
thread in this newsgroup and this is at least his 4th missionary stint
to this newsgroup this year.
> bud will now reply with nasty and insulting comments because he is
> paid to do so.
If poor w had valid technical arguments he wouldn't have to lie about
others.
Never seen - anyone that agrees with w that plug-in suppressors are
effective.
Never answered - any questions. Current questions from the other thread:
- Why do the only 2 examples of protection in the IEEE guide use plug-in
suppressors?
- Why does the NIST guide says plug-in suppressors are "the easiest
solution"?
- Why does the NIST guide say "One effective solution is to have the
consumer install" a multiport plug-in suppressor?
- How would a service panel suppressor provide any protection in the
IEEE example, pdf page 42?
- Why does the IEEE guide say for distant service points "the only
effective way of protecting the equipment is to use a multiport
[plug-in] protector"?
- Why did Martzloff say in his paper "One solution. illustrated in this
paper, is the insertion of a properly designed [multiport plug-in surge
suppressor]"?
- Why do your "responsible manufacturers" make plug-in suppressors?
- Why does "responsible" manufacturer SquareD says "electronic
equipment may need additional protection by installing plug-in
[suppressors] at the point of use"?
- Where is a source that says protection is "inside every appliance"?
- How do you protect airplanes from direct lightning strikes? Do they
drag an earthing chain?
And (with some overlap):
1 - Do appliances and electronics typically have some built-in surge
protection, eg MOVs? Yes or no.
2 - If the answer to 1 is yes, which we all know to be the case, then
how can that surge protection work without a direct earth ground?
3 - How can aircraft be protected from surges, caused by lightning or
static in the air, since they have no direct earth ground?
For real science read the IEEE and NIST guides. Both say plug-in
suppressors are effective.
--
bud--
westom
> Never? Only on theory. On a direct mega hit nothing survives. I
Direct strikes without damage are routine. If damage does happen,
a human has made a mistake. Never, but we humans have no way to test
our designs. First test is when a direct strike occurs. If surge
damage occurs, we humans have made a mistake. Then go looking for
where we made that mistake. But as long as the simple surge
protection system is properly installed, then direct lightning strikes
do not cause damage even to the protector.
An example. In one location, lightning struck incoming power,
ignored the building single point earth ground, and traveled across
the house. Why? Apparently a vein of graphite existed on far side.
Better earth ground was through the house into that graphite vein.
Damage occurred which means we made a mistake. Solution was to expand
single point earth ground a buried loop outside the building.
Incoming surges could obtained earth on a buried loop; need not find
earth ground destructively inside the house.
Human failure corrected. Direct strikes without damage. Geology is
a critical part for protecting household appliances. The protector is
westom
> And if the only possible way of dealing with surges is an earth
> ground, how is it that aircraft have surge protection which deals with
> static discharge and lightning strikes?
Aircraft use same protection techniques. In fact, runways must be
specially constructed with earthing so that surge protection and
static discharge problems are automatically eliminated. Connecting an
airplane to a better earthig is an essential part of aircraft safety
procedures. Protection is never about stopping or absorbing surges or
static. Protection even in aircraft is about diverting a surge so
that energy is harmlessly dissipated elsewhere.
Of course trader has read this previously - should know it by now if
trying to learn rather than just make wild accusations. His agenda is
to create confusion. Obviously, the OP is not asking about power
strip protectors in series on an airplane. Why is trader?
E Z Peaces
I started at page 40 but couldn't find a diagram of what you're talking
about. I will agree that there can be pitfalls when a system is
connected to more than one ground.
Stormin Mormon
volts. The second one trips if the voltage reaches 200
volts. How would that add up? I say, not at all.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"Caesar Romano" <Sp...@uce.gov> wrote in message
news:t4vrv4lfs9gsdq72n...@4ax.com...
Jim Yanik
news:gts2nr$li3$2...@news.motzarella.org:
> Lets say the first one trips, if the voltage reaches 200
> volts. The second one trips if the voltage reaches 200
> volts. How would that add up? I say, not at all.
>
OTOH,if there's enough energy to blow past the first protector,the 2nd will
absorb/shunt it. The 1st protector also acts as a delay,slows down the rise
of the pulse.
--
Jim Yanik
jyanik
at
kua.net
bud--
I stumbled across the instructions for one the 2 plug-in suppressors I
use. It says:
"All Belkin Surge Protectors must be plugged directly into a properly
wired AC power line ... and must not be 'daisy-chained' together in
serial fashion with other power strips, UPSes, other surge protectors,
... or extension cords."
Perhaps ransley could find where Tripp Lite says in writing plug-in
suppressors can be daisy chained. I didn't think phone techs were held
in high regard.
The example in the IEEE guide, pdf page 40, document page 31, "4.1
Ground Potential Rise within a Building".
--
bud--
tra...@optonline.net
> On May 5, 1:02 pm, trad...@optonline.net wrote:
>
> > And if the only possible way of dealing with surges is an earth
> > ground, how is it that aircraft have surge protection which deals with
> > static discharge and lightning strikes?
>
> Aircraft use same protection techniques.
Uh huh. Now we're getting somewhere. They do use some of the same
protection techniques. And that includes surge protection that uses
clamping to keep various parts of aircraft systems at the same
potential.
But they sure don't have a direct, short connection to earth ground,
which you have claimed many, many times is the only way to have any
protection.
> In fact, runways must be
> specially constructed with earthing so that surge protection and
> static discharge problems are automatically eliminated. Connecting an
> airplane to a better earthig is an essential part of aircraft safety
> procedures.
Funny how you now want to move the discussion to aircraft on the
ground. What about when they are at 40,000 ft, with no earth
ground?
>Protection is never about stopping or absorbing surges or
> static. Protection even in aircraft is about diverting a surge so
> that energy is harmlessly dissipated elsewhere.
>
> Of course trader has read this previously - should know it by now if
> trying to learn rather than just make wild accusations. His agenda is
> to create confusion. Obviously, the OP is not asking about power
> strip protectors in series on an airplane. Why is trader?
Oh bother. Buds agenda is to sell surge protectors. Now my agenda
is to create confusion, because I point out obvious big holes and
contradictions in your assertions. What's your agenda?
westom
<cayoung61**spambloc...@hotmail.com> wrote:
> Lets say the first one trips, if the voltage reaches 200
> volts. The second one trips if the voltage reaches 200
> volts. How would that add up? I say, not at all.
No surge protector trips. Where is this device inside that power
strip that disconnects appliance from AC mains? This 'tripping' myth
is the claim that a protector will stop and absorb what even three
miles of sky could not stop.
What is that 'tripping' device? You made the claim. What does this
tripping?
Why is 'let-through' voltage at 330 volts? Where does 200 volts
come from? What is this device inside a protector that measures and
trips on voltage? Surges are measures in amperes. What measures and
trips on 200 volts?
E Z Peaces
> E Z Peaces wrote:
>> bud-- wrote:
>>> ransley wrote:
> I stumbled across the instructions for one the 2 plug-in suppressors I
> use. It says:
> "All Belkin Surge Protectors must be plugged directly into a properly
> wired AC power line ... and must not be 'daisy-chained' together in
> serial fashion with other power strips, UPSes, other surge protectors,
> ... or extension cords."
>
> Perhaps ransley could find where Tripp Lite says in writing plug-in
> suppressors can be daisy chained. I didn't think phone techs were held
> in high regard.
I believe one could get into trouble daisy chaining. I wish I could see
diagrams to understand what could go wrong.
Years ago, I was impressed with the argument at the website of an
English manufacturer (Zero Surge?) that if your phone ground electrode
wasn't bonded to your power ground electrode, it was safer not to plug
your phone line into your point-of-use protector. That's the kind of
thing where a diagram would refresh my memory.
In the 80s, my BIL kept having to send his modems in to have the
lightning-protection fuses replaced. He was using a Radio Shack
gas-tube protector for his phone line. Finally, the modem manufacturer
told him to get a better protector. He got a Tripp Lite and had no more
trouble. The threshold of the gas tubes was too high to protect the
modem fuses.
>
>>> (Incidently I like Tripp Lite as a brand.)
>>>
>>> Results may not be predictable when using 2 suppressors in series.
>>> Take the example in the IEEE guide
>>> <http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf>
>>>
>>> starting pdf page 40. There is as surge coming in on the cable
>>> service. Because the �ground� wire from the cable entry block to the
>>> system ground at the power service is far too long (30 feet) there is
>>> 10,000V between the power ground and the cable ground. That appears
>>> at TVs connected to both power and cable. The example shows how a
>>> plug-in suppressor protects connected equipment.
>>>
>> I started at page 40 but couldn't find a diagram of what you're
>> talking about. I will agree that there can be pitfalls when a system
>> is connected to more than one ground.
>
> The example in the IEEE guide, pdf page 40, document page 31, "4.1
> Ground Potential Rise within a Building".
>
Ahh! I was starting at document page 40.
That example uses a TV plugged into a different outlet from the cable
protector. Wouldn't it be better to plug the TV into an extension cord
daisy chained with the cable protector?
bud--
> bud-- wrote:
>> E Z Peaces wrote:
>>> bud-- wrote:
>>>> ransley wrote:
>
>> I stumbled across the instructions for one the 2 plug-in suppressors I
>> use. It says:
>> "All Belkin Surge Protectors must be plugged directly into a properly
>> wired AC power line ... and must not be 'daisy-chained' together in
>> serial fashion with other power strips, UPSes, other surge protectors,
>> ... or extension cords."
>>
>> Perhaps ransley could find where Tripp Lite says in writing plug-in
>> suppressors can be daisy chained. I didn't think phone techs were held
>> in high regard.
>
> I believe one could get into trouble daisy chaining. I wish I could see
> diagrams to understand what could go wrong.
>
> Years ago, I was impressed with the argument at the website of an
> English manufacturer (Zero Surge?) that if your phone ground electrode
> wasn't bonded to your power ground electrode, it was safer not to plug
> your phone line into your point-of-use protector. That's the kind of
> thing where a diagram would refresh my memory.
If the phone grounding electrode isn't bonded to the power system ground
you better not connect anything to both the power and phone lines (like
a computer). A plug-in suppressor would give you a chance.
For good protection, not only must the phone entry protector connect to
the "ground" at the power system, the connection must be with a short
wire to prevent high voltage between power and phone lines. That is the
moral of the IEEE illustration (starting pdf page 40) for cable. In the
case of a wire that is too long the IEEE guide says "the only effective
way of protecting the equipment is to use a multiport [plug-in]
protector." (Ignored, of course, by w.)
Not bonding is a code violation in the US, and I believe all phone
companies are indoctrinated into making the connection. They don't
necessarily understand the importance of a short connection. And if the
phone entry location is distant from the power service you can't have a
short connection.
> In the 80s, my BIL kept having to send his modems in to have the
> lightning-protection fuses replaced. He was using a Radio Shack
> gas-tube protector for his phone line. Finally, the modem manufacturer
> told him to get a better protector. He got a Tripp Lite and had no more
> trouble. The threshold of the gas tubes was too high to protect the
> modem fuses.
>
>
>>
>>>> (Incidently I like Tripp Lite as a brand.)
>>>>
>>>> Results may not be predictable when using 2 suppressors in series.
>>>> Take the example in the IEEE guide
>>>> <http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf>
>>>>
>>>> starting pdf page 40. There is as surge coming in on the cable
>>>> service. Because the �ground� wire from the cable entry block to the
>>>> system ground at the power service is far too long (30 feet) there
>>>> is 10,000V between the power ground and the cable ground. That
>>>> appears at TVs connected to both power and cable. The example shows
>>>> how a plug-in suppressor protects connected equipment.
>>>>
>
>>> I started at page 40 but couldn't find a diagram of what you're
>>> talking about. I will agree that there can be pitfalls when a system
>>> is connected to more than one ground.
>>
>> The example in the IEEE guide, pdf page 40, document page 31, "4.1
>> Ground Potential Rise within a Building".
>>
> Ahh! I was starting at document page 40.
Yea - I used to have that problem a lot.
> That example uses a TV plugged into a different outlet from the cable
> protector. Wouldn't it be better to plug the TV into an extension cord
> daisy chained with the cable protector?
It would be better than what is shown. A lot better idea to not use an
extension cord from the TV to the suppressor and use a second
suppressor. They aren't real expensive (unless you only buy Monster
products like w).
--
bud--
E Z Peaces
> E Z Peaces wrote:
>> bud-- wrote:
>>
>> Years ago, I was impressed with the argument at the website of an
>> English manufacturer (Zero Surge?) that if your phone ground electrode
>> wasn't bonded to your power ground electrode, it was safer not to plug
>> your phone line into your point-of-use protector. That's the kind of
>> thing where a diagram would refresh my memory.
>
> If the phone grounding electrode isn't bonded to the power system ground
> you better not connect anything to both the power and phone lines (like
> a computer). A plug-in suppressor would give you a chance.
>
> For good protection, not only must the phone entry protector connect to
> the "ground" at the power system, the connection must be with a short
> wire to prevent high voltage between power and phone lines. That is the
> moral of the IEEE illustration (starting pdf page 40) for cable. In the
> case of a wire that is too long the IEEE guide says "the only effective
> way of protecting the equipment is to use a multiport [plug-in]
> protector." (Ignored, of course, by w.)
I was mistaken. Zero Surge is American. Now they recommend against
multiport protectors.
http://www.zerosurge.com/HTML/teleres.html
They don't explain it with diagrams. Switching to a multiport stopped
my BIL's modem from blowing its fuses.
>
> Not bonding is a code violation in the US, and I believe all phone
> companies are indoctrinated into making the connection. They don't
> necessarily understand the importance of a short connection. And if the
> phone entry location is distant from the power service you can't have a
> short connection.
My SEs are 20 feet apart. I bonded them after I found 0.25VAC between
the electrodes. I was online when lightning hit a tree 30 feet from my
power SE. I had no damage, but the phone man had to replace the "fuses"
on the telephone pole. (They call them something else.)
I told him I thought bonding had saved me. He beat around the bush for
20 minutes, then said the code requires it but it's phone-company policy
not to comply. He said surges usually come in on the power company's
neutral. If the electrodes are bonded, the clamping of the phone
company's SE protector can send the surge into the phone line. That's
why he had to replace his fuses.
The lack of bonding appears common around here. It may save the phone
company a few fuses, but it puts the lives and equipment of residents at
risk.
Across the street, my neighbor refused to bond his electrodes. The bolt
that struck my house didn't damage any of my phone/computer equipment,
but it got his modem, computer, cordless phones, and satellite receiver.
He called the phone company, and there technician said there was
nothing wrong with the grounding. So my neighbor told me I was wrong.
His BIL is a power-company executive. He said I was right. So my
neighbor had the phone guy return. This time the phone guy admitted
that the code required bonding and it was the phone company's
responsibility. He said he would expedite it if my neighbor would give
him free music lessons. My neighbor agreed, but the phone man never
returned and the electrodes are still not bonded.
>
>> That example uses a TV plugged into a different outlet from the cable
>> protector. Wouldn't it be better to plug the TV into an extension
>> cord daisy chained with the cable protector?
>
> It would be better than what is shown. A lot better idea to not use an
> extension cord from the TV to the suppressor and use a second
> suppressor. They aren't real expensive (unless you only buy Monster
> products like w).
>
Are you talking about something other than daisy chaining?
westom
> Uh huh. Now we're getting somewhere. They do use some of the same
> protection techniques. And that includes surge protection that uses
> clamping to keep various parts of aircraft systems at the same
> potential.
Aircraft have two wire AC circuits with daisy chained power strip
protectors? How many times do you post irrelevant to the OP's
questions? Even airplanes need earthing which is why runways have
extensive earthing systems to ground airplanes. And still completely
irrelevant to the OP's question - which trader does not answer.
Why did plug-in protectors damage a network of powered off
computers? Protectors without earthing do not absorb surges as trader
claims. Do not absorb surges as a daisy chain of power strips must
do. Those protectors - even if in a daisy chain - simply gave a surge
more paths to find earth ground destructively through the entire
network. Diverts the surge to earth - which can be through the
adjacent computer or TV if too close to appliances and too far from
earth ground. Protector simply gave a surge on more wires - and put
many thousands of volts onto those appliances.
How curious. Page 42 Figure 8. Using a power strip protector, the
surge was earthed 8000 volts destructively through an adjacent TV.
Nothing stops or absorbs surges. Same problem that we engineers saw
and corrected by earthing a 'whole hosue' protector - and no power
strip protectors..
Surge protection is about keeping surges outside the building.
Current that does not flow inside a building and does not flow through
appliances causes no damage. Current that is diverted harmlessly into
earth creates no destructive voltage. Simple solution that also costs
less money. Better earthing and only one 'whole house' protector is
even necessary to protect power strip protectors as well as protect
everything else. An effective protector that costs the OP maybe $1
per appliance.
What does trader recommend? He wants to argue about airplanes.
Those with so much animosity also have trouble even remembering the
OP's question. Little hint: the newsgroup is called alt.home.repair.
Not alt.airplane.repair.
tra...@optonline.net
> On May 6, 12:24 pm, trad...@optonline.net wrote:
>
> > Uh huh. Now we're getting somewhere. They do use some of the same
> > protection techniques. And that includes surge protection that uses
> > clamping to keep various parts of aircraft systems at the same
> > potential.
>
> Aircraft have two wire AC circuits with daisy chained power strip
> protectors?
It's irrelevant what circuits they actually have. The key point is
that those circuits are obviously protected against static and
lightning surges while flying at 40,000 ft where there is no earth
ground. According to Tom, no protection is possible without a
direct, short connection to earth ground. So, how can that be?
> How many times do you post irrelevant to the OP's
> questions?
How many times does Tom hyjack a thread and turn it into a rant on the
alleged evil of plug-in surge protectors? Classic example is the
other thread, where the OP asked how to add a ground to a 2 wire
circuit over a slab. Next thing you know, there;s Tom ranting about
plug-ins.
>Even airplanes need earthing which is why runways have
> extensive earthing systems to ground airplanes.
Gee, what happens in the air? Is there earthing there too?
>And still completely
> irrelevant to the OP's question - which trader does not answer.
Bud and a couple others did an excellent job of answering the
question, perhaps you missed it.
>
> Why did plug-in protectors damage a network of powered off
> computers?
Where exactly did this occur? Forgive me if I question your
credibility, but I have to when you misquote an IEEE guide that
actually recommends plug-in protectors and run around telling everyone
that the IEEE says in that guide that it was a plug-in protector that
destroyed a TV. So, link please.
> Protectors without earthing do not absorb surges as trader
> claims.
Never claimed any such thing.
> Do not absorb surges as a daisy chain of power strips must
> do. Those protectors - even if in a daisy chain - simply gave a surge
> more paths to find earth ground destructively through the entire
> network.
With a plug-in surge protector clamping all the wires going into an
appliance, it's very unlikely that path is going to destroy the
appliance. But without it, it is likely that it could be destroyed.
> Diverts the surge to earth - which can be through the
> adjacent computer or TV if too close to appliances and too far from
> earth ground. Protector simply gave a surge on more wires - and put
> many thousands of volts onto those appliances.
>
> How curious. Page 42 Figure 8. Using a power strip protector, the
> surge was earthed 8000 volts destructively through an adjacent TV.
> Nothing stops or absorbs surges. Same problem that we engineers saw
> and corrected by earthing a 'whole hosue' protector - and no power
> strip protectors..
This is a perfect example of how Tom takes anything and everything
out
of context and turns it into an outright lie. Tom doesn't provide any
link so others can easily take a look for themselves and figure out
that it actually says the opposite of what Tom says it does. Here's
the link:
http://www.lightningsafety.com/nlsi_lhm/IEEE_Guide.pdf
An here is what the text associated with the referenced figure 8 on
page 42 actually says. Pay special attention to the last sentence.
"Figure 8: Ground potential differences within a building under
lightning strike
conditions: how down-line TV sets get damaged. With a 3,000A surge
rising in 3 ìs,
and a 30 foot ground bond (A-C), ~10,000 V develops between A and C.
Even with a
multi-port protector (D) for TV1, the ground voltage at D is conveyed
to TV2 by the
coaxial cable, resulting in an 8,000 V potential across TV2, which
will probably destroy
it. A second multi-port protector as shown in Fig. 7 is required to
protect TV2"
Clearly the IEEE did not say that the damage at TV2 is CAUSED in any
way by the surge surpressor on TV1. And they clearly say that using
a plug-in surge protector on TV2 would protect it, which is 180 deg
opposite of everything that Tom says.
>
> Surge protection is about keeping surges outside the building.
You've already forgotten what I just taught you a few posts ago.
Even with a whole house surge protector, in most cases surges are not
kept outside the building. The surge protector is typically located
bud--
> bud-- wrote:
>> E Z Peaces wrote:
>>> bud-- wrote:
>>>> E Z Peaces wrote:
>
>>>
>>> Years ago, I was impressed with the argument at the website of an
>>> English manufacturer (Zero Surge?) that if your phone ground
>>> electrode wasn't bonded to your power ground electrode, it was safer
>>> not to plug your phone line into your point-of-use protector. That's
>>> the kind of thing where a diagram would refresh my memory.
>>
>> If the phone grounding electrode isn't bonded to the power system
>> ground you better not connect anything to both the power and phone
>> lines (like a computer). A plug-in suppressor would give you a chance.
>>
>> For good protection, not only must the phone entry protector connect
>> to the "ground" at the power system, the connection must be with a
>> short wire to prevent high voltage between power and phone lines. That
>> is the moral of the IEEE illustration (starting pdf page 40) for
>> cable. In the case of a wire that is too long the IEEE guide says "the
>> only effective way of protecting the equipment is to use a multiport
>> [plug-in] protector." (Ignored, of course, by w.)
>
> I was mistaken. Zero Surge is American. Now they recommend against
> multiport protectors.
> http://www.zerosurge.com/HTML/teleres.html
Zero Surge does not use MOVs in their suppressors. Their pitch is to
discredit MOV based suppressors. Their propaganda, last I looked, was
kinda ridiculous.
If there is high voltage between power and signal wires you can't
protect without a multiport suppressor. The NIST guide suggests
equipment is most likely to be damaged by high voltage between power and
signal wires.
>
> They don't explain it with diagrams. Switching to a multiport stopped
> my BIL's modem from blowing its fuses.
>>
>> Not bonding is a code violation in the US, and I believe all phone
>> companies are indoctrinated into making the connection. They don't
>> necessarily understand the importance of a short connection. And if
>> the phone entry location is distant from the power service you can't
>> have a short connection.
>
> My SEs are 20 feet apart. I bonded them after I found 0.25VAC between
> the electrodes. I was online when lightning hit a tree 30 feet from my
> power SE. I had no damage, but the phone man had to replace the "fuses"
> on the telephone pole. (They call them something else.)
With thousands of amps from a lightning strike spreading out from the
point of earthing the potential of the earth rises. It is easy to get
thousands of volts between separated ground rods near the strike. The
thousands of volts will appear at equipment connected to power and phone
wires.
The IEEE guide says you can have the same problem at equipment like a
pad mounted A/C compressor/condenser. With a very near strike the pad
and equipment can be a very different potential from the power system
ground and power wires.
> I told him I thought bonding had saved me. He beat around the bush for
> 20 minutes, then said the code requires it but it's phone-company policy
> not to comply. He said surges usually come in on the power company's
> neutral. If the electrodes are bonded, the clamping of the phone
> company's SE protector can send the surge into the phone line. That's
> why he had to replace his fuses.
It should be illegal to be that stupid.
If a strong surge on power wires is earthed through its ground rod the
potential at the distant phone ground rod can be thousands of volts
different.
> The lack of bonding appears common around here. It may save the phone
> company a few fuses, but it puts the lives and equipment of residents at
> risk.
>
> Across the street, my neighbor refused to bond his electrodes. The bolt
> that struck my house didn't damage any of my phone/computer equipment,
> but it got his modem, computer, cordless phones, and satellite receiver.
> He called the phone company, and there technician said there was
> nothing wrong with the grounding. So my neighbor told me I was wrong.
>
> His BIL is a power-company executive. He said I was right. So my
> neighbor had the phone guy return. This time the phone guy admitted
> that the code required bonding and it was the phone company's
> responsibility. He said he would expedite it if my neighbor would give
> him free music lessons. My neighbor agreed, but the phone man never
> returned and the electrodes are still not bonded.
It sure inspires confidence when you know what to do and the utility
still does it wrong.
The phone company should be liable for any damage.
You could try a complaint to whatever agency regulates the phone company
to get compliance at all installations. In MN some dish installers were
required to go back and properly bond their installations.
>>> That example uses a TV plugged into a different outlet from the cable
>>> protector. Wouldn't it be better to plug the TV into an extension
>>> cord daisy chained with the cable protector?
>>
>> It would be better than what is shown. A lot better idea to not use an
>> extension cord from the TV to the suppressor and use a second
>> suppressor. They aren't real expensive (unless you only buy Monster
>> products like w).
>>
> Are you talking about something other than daisy chaining?
I don�t like daisy chaining. I am talking about a separate suppressor at
the 2nd TV plugged into the outlet at the 2nd TV with the cable wire
going through it. (It is what the IEEE guide says to do.)
--
bud--
westom
> Even with a multi-portprotector(D) for TV1, the ground voltage
> at D is conveyed to TV2 by the coaxial cable, resulting in an
> 8,000 V potential across TV2, which will probably destroy it.
> protect TV2"
What did that protector do? To provide protection, surge energy
must be dissipated somewhere. A connection to earth was 8000 volts
through TV2. Or you must spend $5000 or $15,000 for plug-in
protectors for everything ... dishwasher, microwave, bathroom GFCI,
dimmer switches, timer switches, smoke detectors ... to have
protection. IOW enrich bud.
Where damage can never happen, ie telco CO (switching center), they
don't waste money on plug-in protectors. Responsible facilities earth
a 'whole house' protector on every incoming wire. Now the surge need
not find earth ground destructively through TV2, the furnace, washing
machine, etc. Instead, the surge is earthed before entering the
building. Effective protection for about $1 per appliance.
Or we can argue to create more confusion. If the surge enters a the
breaker box and is then earthed five feet outside that box, is a surge
in any bedroom, living room, hallway, kitchen, etc? Of course not.
Because that surge does not enter the building - no matter how trader
spins confusion.
Next trader will discuss airplanes to create even more confusion?
Page 42 Figure 8. A surge is permitted inside the building. Surge
finds earth ground such as 8000 volts destructively through TV2.
Surges earthed before entering a building will not overwhelm
protection that is already inside every appliance. Anywhere that
surge damage cannot happen: earthing and a 'whole house' protector.
No earth ground means no effective protection. OR the surge finds
earth ground 8000 volts destructively through adjacent appliances.
How curious. bud's NIST citation says the exact same thing:
> A very important point to keep in mind is that your surge
> protector will work by diverting the surges to ground. The
> best surge protection in the world can be useless if
> grounding is not done properly.
Page 42 Figure 8. No earthed protector. So that protector simply
*diverted* that surge 8000 volts destructively through TV2. Page 42
Figure 8 - even the world's best power strip is useless BECAUSE
grounding is not done properly.
So do you discuss airplanes again? trader is not trying to
confuse anyone?
Surge protection means that energy is harmlessly dissipated in
earth; need not even enter the building to 8000 volts destroy the
adjacent TV. A protector is only as effective as its earth ground ...
which is necessary for any building that must never suffer damage.
$1 per protected appliance or $5000 in power strip protectors.
E Z Peaces
> E Z Peaces wrote:
>
>> I told him I thought bonding had saved me. He beat around the bush
>> for 20 minutes, then said the code requires it but it's phone-company
>> policy not to comply. He said surges usually come in on the power
>> company's neutral. If the electrodes are bonded, the clamping of the
>> phone company's SE protector can send the surge into the phone line.
>> That's why he had to replace his fuses.
>
> It should be illegal to be that stupid.
They're $aving fu$e$. A corporation's duty is to maximize profits.
>
> If a strong surge on power wires is earthed through its ground rod the
> potential at the distant phone ground rod can be thousands of volts
> different.
The distance between a cow's hooves is enough to wipe out a herd when
lightning strikes a nearby tree.
>> His BIL is a power-company executive. He said I was right. So my
>> neighbor had the phone guy return. This time the phone guy admitted
>> that the code required bonding and it was the phone company's
>> responsibility. He said he would expedite it if my neighbor would
>> give him free music lessons. My neighbor agreed, but the phone man
>> never returned and the electrodes are still not bonded.
>
> It sure inspires confidence when you know what to do and the utility
> still does it wrong.
>
> The phone company should be liable for any damage.
>
> You could try a complaint to whatever agency regulates the phone company
> to get compliance at all installations. In MN some dish installers were
> required to go back and properly bond their installations.
It must be widely known. I suspect that Bellsouth owns NC regulators.
My neighbor calls himself a handyman but won't take ten minutes and ten
cents to remedy the problem.
>
>>>> That example uses a TV plugged into a different outlet from the
>>>> cable protector. Wouldn't it be better to plug the TV into an
>>>> extension cord daisy chained with the cable protector?
>>>
>>> It would be better than what is shown. A lot better idea to not use
>>> an extension cord from the TV to the suppressor and use a second
>>> suppressor. They aren't real expensive (unless you only buy Monster
>>> products like w).
>>>
>> Are you talking about something other than daisy chaining?
>
> I don�t like daisy chaining. I am talking about a separate suppressor at
> the 2nd TV plugged into the outlet at the 2nd TV with the cable wire
> going through it. (It is what the IEEE guide says to do.)
>
In that case, if during a strike, the ground at one outlet is far
different from the ground at the other, won't you get a surge through
the shield of the cable? Won't that induce high voltage in the signal
conductor? I believe a cable company uses special technology to deal
with the problem between their facility and your service entrance, but
it's your problem within your house.
tra...@optonline.net
> On May 6, 6:27 pm, trad...@optonline.net wrote:
>
> > Even with a multi-portprotector(D) for TV1, the ground voltage
> > at D is conveyed to TV2 by the coaxial cable, resulting in an
> > 8,000 V potential across TV2, which will probably destroy it.
> > A second multi-portprotectoras shown in Fig. 7 is required to
> > protect TV2"
>
> What did that protector do?
According to the IEEE guide, the plug-in surge protector protected TV1
from damage. And they clearly state that had TV2, ie the damaged TV,
had a plug-in, it too would have been protected. They state that
the lightning strike raises the ground potential at one end of the
house by thousands of volts and that is carried by the COAXIAL CABLE
to damage TV2. In other words, everything, as usual is 180 deg
opposite of what you claim it says.
> To provide protection, surge energy
> must be dissipated somewhere. A connection to earth was 8000 volts
> through TV2. Or you must spend $5000 or $15,000 for plug-in
> protectors for everything ... dishwasher, microwave, bathroom GFCI,
> dimmer switches, timer switches, smoke detectors ... to have
> protection. IOW enrich bud.
The above claim that it costs $5K- $15K for plug-in surge protectors
for a house gives a good view into your lack of grounding in
reality. Pun intended.
>
> Where damage can never happen, ie telco CO (switching center), they
> don't waste money on plug-in protectors. Responsible facilities earth
> a 'whole house' protector on every incoming wire.
As I pointed out to you in a previous thread, not only does the telco
CO have surge protection at the point of entry, they also have surge
protection on every line card where the phone line actually terminates
at the CO switch. That protection typically includes MOVs, which
operate on the line card, as they do inside appliances or plug-in
surge protectors. Which is to say protection is provided without the
benefit of a direct short connection to earth ground, which is 180 deg
opposite to what you claim. I even provided you with a datasheet from
National Semiconductor for their line card semiconductors, where they
discuss the fact that protection must be provided on the line card.
One more credible reference that refutes what you claim, but you just
ignore.
> Now the surge need
> not find earth ground destructively through TV2, the furnace, washing
> machine, etc. Instead, the surge is earthed before entering the
> building. Effective protection for about $1 per appliance.
>
> Or we can argue to create more confusion. If the surge enters a the
> breaker box and is then earthed five feet outside that box, is a surge
> in any bedroom, living room, hallway, kitchen, etc? Of course not.
Of course all the credible references say that just isn't so. Bud
has explained this to you a dozen times. A lightning strike has such
a high current, that even with a well grounded system, the current
going through the whole house surge protector can result in thousands
of volts still being present. Do the math. 10,000 amps times 1
ohm=?
> Because that surge does not enter the building - no matter how trader
> spins confusion.
Explained to you yesterday, why this is wrong X2. Not only is a
surge still possible even with a whole house protector, but even the
main surge going through the whole house protector, in most cases, is
actually inside the house because the AC panel with the surge
protector is typically located inside the house.
>
> Next trader will discuss airplanes to create even more confusion?
>
> Page 42 Figure 8. A surge is permitted inside the building. Surge
> finds earth ground such as 8000 volts destructively through TV2.
> Surges earthed before entering a building will not overwhelm
> protection that is already inside every appliance. Anywhere that
> surge damage cannot happen: earthing and a 'whole house' protector.
> No earth ground means no effective protection.
How is it that aircraft at 40,000 feet are protected then?
> OR the surge finds
> earth ground 8000 volts destructively through adjacent appliances.
>
> How curious. bud's NIST citation says the exact same thing:
> > A very important point to keep in mind is that your surge
> > protector will work by diverting the surges to ground. The
> > best surge protection in the world can be useless if
> > grounding is not done properly.
>
> Page 42 Figure 8. No earthed protector. So that protector simply
> *diverted* that surge 8000 volts destructively through TV2.
As Bud would say, the lie repeated.
Page 42
> Figure 8 - even the world's best power strip is useless BECAUSE
> grounding is not done properly.
Which of course is NOT what the referrence actually says:
"Even with a multi-port protector (D) for TV1, the ground voltage at D
is conveyed to TV2 by the coaxial cable, resulting in an 8,000 V
potential across TV2, which will probably destroy it. A second multi-
port protector as shown in Fig. 7 is required to protect TV2."
ransley
>
> >> starting pdf page 40. There is as surge coming in on the cable
> >> system ground at the power service is far too long (30 feet) there is
> >> 10,000V between the power ground and the cable ground. That appears at
> >> TVs connected to both power and cable. The example shows how a plug-in
> >> suppressor protects connected equipment.
>
> >> Now use 2 suppressors connected in series with the 2nd connected to
> >> the TV and the cable going through the 2nd. There will be a current
> >> through cable sheath and power ground wire which lifts the ground at
> >> the suppressors away from the ground at the power service (as is
> >> clearly indicated in the IEEE example). That lifts the ground at the
> >> suppressors from the hot and neutral so the MOVs will limit the
> >> voltage H-G, N-G. If the only MOVs that conduct are in the 1st
> >> suppressor you will have the ground wire in the line cord to the 2nd
> >> suppressor (maybe 6 feet) separating the power ground reference and
> >> the cable ground reference. The voltage drop over 6 feet of the ground
> >> wire from the cable entry ground block to the power service is 2,000V.
> >> It will be far lower in the line cord but will add to the difference
> >> in voltage between the power and cable wires going to the TV. Is that
> >> a problem? Who knows - but I would rather not run the science project.
>
> >> Multiple MOVs in a single suppressor do not have 6 feet between them.
>
> >> Since suppressors with high ratings are readily and cheaply available
> >> maybe to connect a UPS with relatively low ratings downstream from a
> >> high rated plug-in suppressor).
>
> > I started at page 40 but couldn't find a diagram of what you're talking
> > about. I will agree that there can be pitfalls when a system is
> > connected to more than one ground.
>
> The example in the IEEE guide, pdf page 40, document page 31, "4.1
> Ground Potential Rise within a Building".
>
> --
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
They are made here where I live in Chicago. I talked to a few people
at Tripp here after a few of their units took the beating of a major
strike, the tripps literaly smoked, and what they were used on
survived. Where I didnt have them I fried. I can see several points
why it would not be recommended by them in writing, but by their
design of the units I use, and that being each socket further away
from the 120v wall plug having an additional Mov, it just makes sense
it works. In reality daisy chaining may do nothing as I believe their
better units do all that can be expected of them. Gee I hate
lightning, it can ruin a nice day.
bud--
Likely.
There is surge current on the shield from the cable entry ground block
to the 1st plug-in suppressor that is likely larger.
And surge current on the cable service shield to the ground block that
is much larger.
> Won't that induce high voltage in the signal
> conductor?
I wouldn't say induce.
If you pull the shield to a different potential, the signal conductor
could be nearer the far end potential. Plug-in suppressors limit the
voltage from signal conductor to the ground at the suppressor, just like
all other wires. It is one reason to use a plug-in suppressor.
The same problem is likely at the 1st suppressor.
And the same problem is likely at the cable entry ground block. It is a
problem that w ignores because it does not fit in with his religious
views. w says the only cable protection you need is the entry ground block.
> I believe a cable company uses special technology to deal
> with the problem between their facility and your service entrance, but
> it's your problem within your house.
Haven't heard of any cable company technology.
With cable shields connected to earth at each house (and earth potential
different) I don't know why there isn't a major ground loop problem (not
surge related). Even worse, the neutral is connected to the cable shield
at every house. I would think the hum level would be way above the
signal level. Maybe a high pass filter is very effective.
Anyone know why ground loops aren't a problem?
--
bud--
westom
> "Even with a multi-port protector (D) for TV1, the ground voltage at D
> is conveyed to TV2 by the coaxial cable, resulting in an 8,000 V
> potential across TV2, which will probably destroy it. A second multi-
> port protector as shown in Fig. 7 is required to protect TV2."
TV is 8000 volts damaged because a surge current was permitted
inside the building. That surge current had to find earth ground.
With or without the power strip, it will find earth ground
destructively through some appliance.
We install and earth on 'whole house' protector so that no surge
current enters the building. One properly earthed (ie less than 10
foot) 'whole house' protector means the surge finds and is harmlessly
dissipated in earth. Does not enter the building. Does not get
earthed by the power strip protector 8000 volts through any appliance.
Why do telcos all over the world not use that power strip
protector? They need protectors that make that short connection to
earth – that actually provide protection. They need nothing damaged.
Apparently trader considers appliance damage acceptable.
Same solution is available for all homes. One 'whole house'
protector sells in Lowes for less than $50. That means one protector
for maybe 100 items. But you would have them spend $5000 on power
strips for everything including the furnace, smoke detectors, and
bathroom GFCIs? Which scam are you promoting? An earthed surge does
not overwhelm protection that already exists inside every appliance.
E Z Peaces
> With cable shields connected to earth at each house (and earth potential
> different) I don't know why there isn't a major ground loop problem (not
> surge related). Even worse, the neutral is connected to the cable shield
> at every house. I would think the hum level would be way above the
> signal level. Maybe a high pass filter is very effective.
>
> Anyone know why ground loops aren't a problem?
>
Blocking capacitors? 60 Hz is a long way from 500MHz, for example.
bud--
> On May 8, 9:59 am, trad...@optonline.net wrote:
>> "Even with a multi-port protector (D) for TV1, the ground voltage at D
>> is conveyed to TV2 by the coaxial cable, resulting in an 8,000 V
>> potential across TV2, which will probably destroy it. A second multi-
>> port protector as shown in Fig. 7 is required to protect TV2."
>
> TV is 8000 volts damaged because a surge current was permitted
> inside the building.
TV2 is damaged because it wasn't protected, as anyone but w can figure out.
> We install and earth on 'whole house' protector so that no surge
> current enters the building.
Service panel suppressors are a good idea.
But from the NIST guide:
"Q - Will a surge protector installed at the service entrance be
sufficient for the whole house?
A - There are two answers to than question: Yes for one-link appliances
[electronic equipment], No for two-link appliances [equipment connected
to power AND phone or cable or....]. Since most homes today have some
kind of two-link appliances, the prudent answer to the question would be
NO - but that does not mean that a surge protector installed at the
service entrance is useless."
Service panel suppressors do not prevent high voltages from developing
between power and signal wires. The NIST guide, citing insurance
information, suggests most equipment damage is from high voltage between
power and signal wires.
> One properly earthed (ie less than 10
> foot) 'whole house' protector means the surge finds and is harmlessly
> dissipated in earth. Does not enter the building. Does not get
> earthed by the power strip protector 8000 volts through any appliance.
Ho-hum - the lie repeated.
And in fact a service panel suppressor would provide *NO* protection
from 8000V in the IEEE example. The 8000V comes from the cable service.
w has never explained how a power service suppressor would fix 10,000V
coming in on the cable service.
In fact, for the problem in the IEEE example the IEEE says "the only
effective way of protecting the equipment is to use a multiport
[plug-in] protector."
>
> Why do telcos all over the world not use that power strip
> protector?
As trader has said several times, telcos may use similar protection with
MOVs at the equipment.
Is I have said numerous times it is stupid to suggest a telco switch
would use a plug-in suppressor. A telco switch is high amp, is hard
wired, and would have to have thousands of signal wires going through it.
Of course still never seen - anyone that agrees with w that plug-in
suppressors are effective. Because no one agrees with w.
Of course never answered - simple questions:
- Why do the only 2 examples of protection in the IEEE guide use plug-in
suppressors?
- Why does the NIST guide says plug-in suppressors are "the easiest
solution"?
- Why does the NIST guide say "One effective solution is to have the
consumer install" a multiport plug-in suppressor?
- How would a service panel suppressor provide any protection in the
IEEE example, pdf page 42?
- Why does the IEEE guide say for distant service points "the only
effective way of protecting the equipment is to use a multiport
westom
> Service panel suppressors are a good idea.
> But from the NIST guide:
> "Q - Will a surge protector installed at the service entrance be
> sufficient for the whole house?
> A - There are two answers to than question: Yes for one-link appliances
> [electronic equipment], No for two-link appliances [equipment connected
> to power AND phone or cable or....].
Which is why all those incoming utilities must be properly earth -
ie 'whole house' protectors. Did he forget to mention phone lines
already have a 'whole house' protector install for free at every
home? And that is point. Every incoming wire must be earthed. AC
electric is the missing protection and the source of most all surge
damage.
Numbers from the IEEE Standards. A properly earthed 'whole house'
protector provides 99.5% protection. From that IEEE Standard:
> Still, a 99.5% protection level will reduce the incidence of direct
> strokes from one stroke per 30 years ... to one stroke per
> 6000 years ...
Massive protection at $1 per protected appliance using a 'whole
house' protector. For an additional 0.2% protection, bud recommends
spending $5000 on obscenely profitable plug-in protectors. bud even
forgets what his sources also say: Page 42 Figure 8. Without that
'whole house' protector, the 0.2% protecton can, instead, contribute
to appliance damage.
Without a 'whole house' protector and upgraded earthing, a $25 or
$150 power strip protector can even earth a surge 8000 volts
destructively through adjacent appliances. Page 42 Figure 8. Why
does bud avoid that fact? Profits at risk.
Where is this power strip spec that claims protection? Why does
bud, whose income is promoting these devices - why does he still not
provide those numeric specifications? Because no plug-in protector
claims that protection.
"Protectors in series" assumes protectors will somehow stop and
absorb what three miles of sky could not even stop. So many long half
truths from bud combined with insults .... and he still cannot find
even one numeric specification that actually claims protection.
A protector is only as effective as its earth ground. Either
surge energy is absorbed harmlessly in earth OR it finds destructive
paths to earth via appliances. "Protectors in series" will stop what
three miles of sky could not? Nonsense. Even power strips connected
three miles in series will stop what three miles of sky could not
stop. A protector is only as effective as its connection to earth.
No earth ground means no effective protection. Page 17 his NIST
citation:
> The best surge protection in the world can be useless
> if grounding is not done properly.
No earth ground means no effective protection - no matter how many
scam protectors are connected in series.
sa...@dog.com
wrote:
Cue twilight Zone theme music...
bud--
> On May 10, 1:47 am, bud-- <remove.budn...@isp.com> wrote:
>> Service panel suppressors are a good idea.
>> But from the NIST guide:
>> "Q - Will a surge protector installed at the service entrance be
>> sufficient for the whole house?
>> A - There are two answers to than question: Yes for one-link appliances
>> [electronic equipment], No for two-link appliances [equipment connected
>> to power AND phone or cable or....].
>
> absorb what three miles of sky could not even stop.
Because of his religious blinders poor w can't figure out how plug-in
suppressors work. As the IEEE guide explains for anyone that can think,
it is by clamping.
> A protector is only as effective as its earth ground.
> No earth ground means no effective protection
w's religious mantras protect him from conflicting thoughts (aka reality).
w just repeats the same drivel, as if repetition makes it true.
Still never seen - anyone that agrees with w that plug-in suppressors
are effective. (Because no one agrees with w.)
Still never answered - simple questions: