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Sci.Electronics.Basics -> Re: Surge / Ground / Lightning

There are 10 messages in this thread.
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Author: Franc Zabkar
Date: 18:40 03-05-08

On 3 May 2008 09:46:09 GMT, phil-news-nospam@ipal.net put finger to
keyboard and composed:

>In alt.tv.tech.hdtv Franc Zabkar <fzabkar@iinternode.on.net> wrote:
>| On Thu, 1 May 2008 13:30:31 -0700 (PDT), w_tom <w_tom1@usa.net> put
>| finger to keyboard and composed:
>|
>|>On May 1, 2:18?pm, ransley <Mark_Rans...@yahoo.com> wrote:
>|>> Whaaat, you say my Triplights that offer a life time warranty to
>|>> damages from from surges and lightning offer non such ?claim or
>|>> warranty, thats pure barf. Triplight surge protectors are only one
>|>> step a homeowner needs to hopefully protect you. Ive been hit several
>|>> times, anything you do helps a bit.
>|>
>|> Actually some things installed will decrease protection - ie the TV
>|>destroyed because the plug-in protector earthed an 8000 volt surge
>|>through it.
>|
>| Can you elaborate on this by showing us the path taken by the strike
>| through the TV?
>
>A surge will take _every_ path. Where that ends up with a voltage difference
>somewhere, anywhere, that exceeds the device breakdown voltage, then you will
>have current flow across there. And if that breakdown means damage, as it
>would for things like a CMOS circuit component, the device would be damaged.

True but irrelevant to my question. I wanted specific examples in
support of the claim that "some things installed will decrease
protection".

A strike on the mains would be clamped to the earth pin by MOVs. It
may still be that the antenna provides a second path to earth which
would mean that the TV could be damaged that way. However, the absence
of an earth pin would result in an even higher differential voltage
between mains and antenna which would mean an even greater likelihood
of damage. OTOH, if the strike arrived via the antenna, then the
presence or absence of the earth pin should make very little
difference AFAICS.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Author: Phil Howard
Date: 01:35 04-05-08

In alt.tv.tech.hdtv Franc Zabkar <fzabkar@iinternode.on.net> wrote:
| On 3 May 2008 09:46:09 GMT, phil-news-nospam@ipal.net put finger to
| keyboard and composed:
|
|>In alt.tv.tech.hdtv Franc Zabkar <fzabkar@iinternode.on.net> wrote:
|>| On Thu, 1 May 2008 13:30:31 -0700 (PDT), w_tom <w_tom1@usa.net> put
|>| finger to keyboard and composed:
|>|
|>|>On May 1, 2:18?pm, ransley <Mark_Rans...@yahoo.com> wrote:
|>|>> Whaaat, you say my Triplights that offer a life time warranty to
|>|>> damages from from surges and lightning offer non such ?claim or
|>|>> warranty, thats pure barf. Triplight surge protectors are only one
|>|>> step a homeowner needs to hopefully protect you. Ive been hit several
|>|>> times, anything you do helps a bit.
|>|>
|>|> Actually some things installed will decrease protection - ie the TV
|>|>destroyed because the plug-in protector earthed an 8000 volt surge
|>|>through it.
|>|
|>| Can you elaborate on this by showing us the path taken by the strike
|>| through the TV?
|>
|>A surge will take _every_ path. Where that ends up with a voltage difference
|>somewhere, anywhere, that exceeds the device breakdown voltage, then you will
|>have current flow across there. And if that breakdown means damage, as it
|>would for things like a CMOS circuit component, the device would be damaged.
|
| True but irrelevant to my question. I wanted specific examples in
| support of the claim that "some things installed will decrease
| protection".

Installing something that ends up creating a situation where you will have a
big voltage difference where you otherwise would not is such an example.

| A strike on the mains would be clamped to the earth pin by MOVs. It
| may still be that the antenna provides a second path to earth which
| would mean that the TV could be damaged that way. However, the absence
| of an earth pin would result in an even higher differential voltage
| between mains and antenna which would mean an even greater likelihood
| of damage. OTOH, if the strike arrived via the antenna, then the
| presence or absence of the earth pin should make very little
| difference AFAICS.

The MOVs will act like conductors when they are clamping. The surge will
take both paths ... the path through the MOVs, and the path going past the
MOVs. In general, about 50% will go each way. That can vary at higher
frequencies.

The antenna "second path to earth" could provide that difference in voltage
that can lead to substantial and damaging current. However, if you bring
the antenna feedline in at the point electric power comes in, and ground
everything in common, then whatever voltage rise you get in low frequencies
will be fairly equal between power connection and antenna connection. The
strike coming in on the antenna is not really any different, except in the
high frequencies. The antenna feedline does not degrade the high frequencies
as much as the power lines.

The high frequencies can still be an issue. They are less common so if you
are just trying to reduce your risk then this is a good start. Most energy
is in lower frequencies (though this varies by means of entry). But there
are ways to deal with the high frequency energy as well, if you want to go
that far. It just depends on how much you want to spend to get how much
protection.

--
|WARNING: Due to extreme spam, I no longer see any articles originating from |
| Google Groups. If you want your postings to be seen by more readers |
| you will need to find a different place to post on Usenet. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |

Author: Leonard Caillouet
Date: 17:55 04-05-08

<phil-news-nospam@ipal.net> wrote in message
news:fvjhvk016vr@news5.newsguy.com...
> In alt.tv.tech.hdtv Franc Zabkar <fzabkar@iinternode.on.net> wrote:

>
> The MOVs will act like conductors when they are clamping. The surge will
> take both paths ... the path through the MOVs, and the path going past the
> MOVs. In general, about 50% will go each way. That can vary at higher
> frequencies.

Why would you assume that 50% will go each way when you don't know the
impedance of each direction? When conducting, or at failure, the MOV has a
very low impedance.

Leonard

Author: Phil Howard
Date: 20:18 04-05-08

In alt.engineering.electrical Leonard Caillouet <nospam@noway.com> wrote:
| <phil-news-nospam@ipal.net> wrote in message
| news:fvjhvk016vr@news5.newsguy.com...
|> In alt.tv.tech.hdtv Franc Zabkar <fzabkar@iinternode.on.net> wrote:
|
|>
|> The MOVs will act like conductors when they are clamping. The surge will
|> take both paths ... the path through the MOVs, and the path going past the
|> MOVs. In general, about 50% will go each way. That can vary at higher
|> frequencies.
|
| Why would you assume that 50% will go each way when you don't know the
| impedance of each direction? When conducting, or at failure, the MOV has a
| very low impedance.

There is a distinction between "go each way" and "what comes back"
due to
the impedance. It will be about 50% that goes each way _because_ the power
itself does not (yet) know the impedance (at a distance), until it gets
there.

There are two kinds of impedance to deal with here. The first (literally)
is the characteristic impedance. At the point of the MOVs themselves, it
will be about the same each way, but it can vary some at higher frequencies.
It depends on the way the MOVs and the connections with them are constructed.

The second is the net impedance of the path beyond the MOV connections.
That impedance is not what I am talking about in my prior statement. Yes,
it plays a part, but it is not infliienced by the MOVs. It would be the
same if you simply shorted the MOVs with a wire (though that certainly
causes other things to not work, so that isn't how protection is done).

Ultimately you do have to consider the _whole_ system to get an accurate view
of exactly what will happen. Generally this is impractical. What you have
to do is understand what can happen with the variations, and try to change
things to make the happenings do what you prefer (e.g. avoid damage to the
protected devices).

One example involved the power wiring. There should be a point where you
have the neutral grounded, and heavy duty MOVs between each hot wire (be
that 1, 2 or 3) and the grounded wire, and between individual hot wires as
well. The grounded wire (referred to as neutral, but incorrectly in some
cases, even though this is the common referral) would be directly connected
to the path to ground. That connection should be with the least impedance
you can possibly get, within your cost/risk criteria. That means a short
and/or heavy conductor. Short to make it more effective at higher frequencies
by reducing inductive impedance. Heavy to handle a greater current flow.
Much of the surge can now take this path to ground. But not all of it will.
To maximize what will take the path to ground, and minimize what goes to the
building loads/devices that could be damaged, you need to have an increased
impedance on that path. Clearly resistors are not workable since that stops
the power itself, which you do not want to impede. What can work is a low
pass filter primarily an inductor. It needs to be made to have very little
effect at 60 Hz and below, yet block energy/power above that as much as is
possible (again, within your cost/risk criteria). The combination of these
things can limit the surge that reaches protected devices to a tiny fraction
of its original energy.

--
|WARNING: Due to extreme spam, I no longer see any articles originating from |
| Google Groups. If you want your postings to be seen by more readers |
| you will need to find a different place to post on Usenet. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |

Author: bud--
Date: 22:15 04-05-08

phil-news-nospam@ipal.net wrote:
> In alt.engineering.electrical Leonard Caillouet <nospam@noway.com> wrote:
> | <phil-news-nospam@ipal.net> wrote in message
> | news:fvjhvk016vr@news5.newsguy.com...
> |> In alt.tv.tech.hdtv Franc Zabkar <fzabkar@iinternode.on.net> wrote:
> |
> |>
> |> The MOVs will act like conductors when they are clamping. The surge will
> |> take both paths ... the path through the MOVs, and the path going past the
> |> MOVs. In general, about 50% will go each way. That can vary at higher
> |> frequencies.
> |
> | Why would you assume that 50% will go each way when you don't know the
> | impedance of each direction? When conducting, or at failure, the MOV has a
> | very low impedance.
>
> There is a distinction between "go each way" and "what comes
back" due to
> the impedance. It will be about 50% that goes each way _because_ the power
> itself does not (yet) know the impedance (at a distance), until it gets
> there.

Another installment of Phil's Phantasy Physics using transmission line
theory.

Two sources directly contradict Phil.

Phil has provided no sources to support phantasy physics.

--
bud--

Author: Phil Howard
Date: 01:44 05-05-08

Date: 12:19 05-05-08

On May 5, 1:44=A0am, phil-news-nos...@ipal.net wrote:
> In alt.tv.tech.hdtv bud-- <remove.budn...@isp.com> wrote:| phil-news-nos..=
.@ipal.net wrote:
>
> |> In alt.engineering.electrical Leonard Caillouet <nos...@noway.com>
wrot=
e:|> | <phil-news-nos...@ipal.net> wrote in message
>
> |> |news:fvjhvk016vr@news5.newsguy.com...
> |> |> In alt.tv.tech.hdtv Franc Zabkar <fzab...@iinternode.on.net>
wrote:
> |> |
> |> |>
> |> |> The MOVs will act like conductors when they are clamping. =A0The sur=
ge will
> |> |> take both paths ... the path through the MOVs, and the path going pa=
st the
> |> |> MOVs. =A0In general, about 50% will go each way. =A0That can vary at=
higher
> |> |> frequencies.
> |> |
> |> | Why would you assume that 50% will go each way when you don't know th=
e
> |> | impedance of each direction? =A0When conducting, or at failure, the M=
OV has a
> |> | very low impedance.
> |>
> |> There is a distinction between "go each way" and "what comes
back" due =
to
> |> the impedance. =A0It will be about 50% that goes each way _because_ the=
power
> |> itself does not (yet) know the impedance (at a distance), until it gets=

> |> there.
> |
> | Another installment of Phil's Phantasy Physics using transmission line
> | theory.
>
> Not understanding it is your loss.

I have to agree that this is Phantasy Physics. We're supposed to
believe that a surge reaching a MOV is going to split 50-50, with half
of it going to the MOV path and half moving on down the line,
reagrdless of the impedance of the two paths? That would render all
surge protection about 50% effective.

>
> | Two sources directly contradict Phil.
>
> What sources? =A0Your truncated out of context quotes?
>
> | Phil has provided no sources to support phantasy physics.
>
> I don't care.
>
> --
> |WARNING: Due to extreme spam, I no longer see any articles originating fr=
om =A0|
> | =A0 =A0 =A0 =A0 Google Groups. If you want your postings to be seen by m=
ore readers |
> | =A0 =A0 =A0 =A0 you will need to find a different place to post on Usene=
t. =A0 =A0 =A0 =A0 =A0|
> | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.n=
et) |

Author: Phil Howard
Date: 14:20 05-05-08

In alt.engineering.electrical trader4@optonline.net wrote:
| On May 5, 1:44?am, phil-news-nos...@ipal.net wrote:
|> In alt.tv.tech.hdtv bud-- <remove.budn...@isp.com> wrote:|
phil-news-nos...@ipal.net wrote:
|>
|> |> In alt.engineering.electrical Leonard Caillouet <nos...@noway.com>
wrote:|> | <phil-news-nos...@ipal.net> wrote in message
|>
|> |> |news:fvjhvk016vr@news5.newsguy.com...
|> |> |> In alt.tv.tech.hdtv Franc Zabkar <fzab...@iinternode.on.net>
wrote:
|> |> |
|> |> |>
|> |> |> The MOVs will act like conductors when they are clamping. ?The surge
will
|> |> |> take both paths ... the path through the MOVs, and the path going past
the
|> |> |> MOVs. ?In general, about 50% will go each way. ?That can vary at
higher
|> |> |> frequencies.
|> |> |
|> |> | Why would you assume that 50% will go each way when you don't know the
|> |> | impedance of each direction? ?When conducting, or at failure, the MOV has
a
|> |> | very low impedance.
|> |>
|> |> There is a distinction between "go each way" and "what comes
back" due to
|> |> the impedance. ?It will be about 50% that goes each way _because_ the power
|> |> itself does not (yet) know the impedance (at a distance), until it gets
|> |> there.
|> |
|> | Another installment of Phil's Phantasy Physics using transmission line
|> | theory.
|>
|> Not understanding it is your loss.
|
|
| I have to agree that this is Phantasy Physics. We're supposed to
| believe that a surge reaching a MOV is going to split 50-50, with half
| of it going to the MOV path and half moving on down the line,
| reagrdless of the impedance of the two paths? That would render all
| surge protection about 50% effective.

You did not read very carefully. The reference to 50-50 split is about the
contribution of the MOVs themselves. That is an essential understanding of
the components so the whole system can be figured out. The impedance down
the paths is another separate component, which also has to be figured in
when determining the whole picture.

You have confused a component with the entire system. You need to read more
carefully. Or you need to understand the distinction of individual components
as they apply to the whole system

The whole wiring system is extrememly complex. It cannot be understood
properly without first understanding the components. And that includes
understanding that MOVs, when they conduct, do look to the propogating
energy as two paths to go down, and it will (initially) go both ways in
about an equal amount.

--
|WARNING: Due to extreme spam, I no longer see any articles originating from |
| Google Groups. If you want your postings to be seen by more readers |
| you will need to find a different place to post on Usenet. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |

Date: 13:06 06-05-08

On May 5, 2:20=A0pm, phil-news-nos...@ipal.net wrote:
> In alt.engineering.electrical trad...@optonline.net wrote:
>
> | On May 5, 1:44?am, phil-news-nos...@ipal.net wrote:
> |> In alt.tv.tech.hdtv bud-- <remove.budn...@isp.com> wrote:|
phil-news-no=
s...@ipal.net wrote:
> |>
> |> |> In alt.engineering.electrical Leonard Caillouet
<nos...@noway.com> w=
rote:|> | <phil-news-nos...@ipal.net> wrote in message
> |>
> |> |> |news:fvjhvk016vr@news5.newsguy.com...
> |> |> |> In alt.tv.tech.hdtv Franc Zabkar
<fzab...@iinternode.on.net> wrot=
e:
> |> |> |
> |> |> |>
> |> |> |> The MOVs will act like conductors when they are clamping. ?The
su=
rge will
> |> |> |> take both paths ... the path through the MOVs, and the path
going=
past the
> |> |> |> MOVs. ?In general, about 50% will go each way. ?That can vary at
=
higher
> |> |> |> frequencies.
> |> |> |
> |> |> | Why would you assume that 50% will go each way when you don't know=
the
> |> |> | impedance of each direction? ?When conducting, or at failure, the =
MOV has a
> |> |> | very low impedance.
> |> |>
> |> |> There is a distinction between "go each way" and "what
comes back" d=
ue to
> |> |> the impedance. ?It will be about 50% that goes each way _because_ th=
e power
> |> |> itself does not (yet) know the impedance (at a distance), until it g=
ets
> |> |> there.
> |> |
> |> | Another installment of Phil's Phantasy Physics using transmission lin=
e
> |> | theory.
> |>
> |> Not understanding it is your loss.
> |
> |
> | I have to agree that this is Phantasy Physics. =A0 =A0We're supposed to
> | believe that a surge reaching a MOV is going to split 50-50, with half
> | of it going to the MOV path and half moving on down the line,
> | reagrdless of the impedance of the two paths? =A0 =A0That would render a=
ll
> | surge protection about 50% effective.
>
> You did not read very carefully. =A0The reference to 50-50 split is about =
the
> contribution of the MOVs themselves. =A0That is an essential understanding=
of
> the components so the whole system can be figured out. =A0The impedance do=
wn
> the paths is another separate component, which also has to be figured in
> when determining the whole picture.
>
> You have confused a component with the entire system. =A0You need to read =
more
> carefully. =A0Or you need to understand the distinction of individual comp=
onents
> as they apply to the whole system
>
> The whole wiring system is extrememly complex. =A0It cannot be understood
> properly without first understanding the components. =A0And that includes
> understanding that MOVs, when they conduct, do look to the propogating
> energy as two paths to go down, and it will (initially) go both ways in
> about an equal amount.

Maybe you should review what you actually stated in the context of
current surge supression discussion:
"
"The MOVs will act like conductors when they are clamping. The surge
will
|> |> take both paths ... the path through the MOVs, and the path
going past the
|> |> MOVs. In general, about 50% will go each way. That can vary at
higher
|> |> frequencies. "

That sure sounds like 50% of the surge is going through the MOV and
the other 50% is going on past it to the protected equipment.

And that I would have to agree with Bud on, it's phantasy physics,
because if it were true, no type of surge protection would work,
because it would only be 50% effective.

>
> --
> |WARNING: Due to extreme spam, I no longer see any articles originating fr=
om =A0|
> | =A0 =A0 =A0 =A0 Google Groups. If you want your postings to be seen by m=
ore readers |
> | =A0 =A0 =A0 =A0 you will need to find a different place to post on Usene=
t. =A0 =A0 =A0 =A0 =A0|
> | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.n=
et) |

Author: bud--
Date: 11:34 07-05-08

trader4@optonline.net wrote:
> On May 5, 2:20 pm, phil-news-nos...@ipal.net wrote:
>> In alt.engineering.electrical trad...@optonline.net wrote:
>>
>> | On May 5, 1:44?am, phil-news-nos...@ipal.net wrote:
>> |> In alt.tv.tech.hdtv bud-- <remove.budn...@isp.com> wrote:|
phil-news-nos...@ipal.net wrote:
>> |>
>> |> |> In alt.engineering.electrical Leonard Caillouet
<nos...@noway.com> wrote:|> | <phil-news-nos...@ipal.net> wrote in message
>> |>
>> |> |> |news:fvjhvk016vr@news5.newsguy.com...
>> |> |> |> In alt.tv.tech.hdtv Franc Zabkar
<fzab...@iinternode.on.net> wrote:
>> |> |> |
>> |> |> |>
>> |> |> |> The MOVs will act like conductors when they are clamping.
?The surge will
>> |> |> |> take both paths ... the path through the MOVs, and the path
going past the
>> |> |> |> MOVs. ?In general, about 50% will go each way. ?That can vary
at higher
>> |> |> |> frequencies.
>> |> |> |
>> |> |> | Why would you assume that 50% will go each way when you don't
know the
>> |> |> | impedance of each direction? ?When conducting, or at failure, the
MOV has a
>> |> |> | very low impedance.
>> |> |>
>> |> |> There is a distinction between "go each way" and
"what comes back" due to
>> |> |> the impedance. ?It will be about 50% that goes each way _because_
the power
>> |> |> itself does not (yet) know the impedance (at a distance), until it
gets
>> |> |> there.
>> |> |
>> |> | Another installment of Phil's Phantasy Physics using transmission line
>> |> | theory.
>> |>
>> |> Not understanding it is your loss.
>> |
>> |
>> | I have to agree that this is Phantasy Physics. We're supposed to
>> | believe that a surge reaching a MOV is going to split 50-50, with half
>> | of it going to the MOV path and half moving on down the line,
>> | reagrdless of the impedance of the two paths? That would render all
>> | surge protection about 50% effective.
>>
>> You did not read very carefully. The reference to 50-50 split is about the
>> contribution of the MOVs themselves. That is an essential understanding of
>> the components so the whole system can be figured out. The impedance down
>> the paths is another separate component, which also has to be figured in
>> when determining the whole picture.
>>
>> You have confused a component with the entire system. You need to read more
>> carefully. Or you need to understand the distinction of individual components
>> as they apply to the whole system
>>
>> The whole wiring system is extrememly complex. It cannot be understood
>> properly without first understanding the components. And that includes
>> understanding that MOVs, when they conduct, do look to the propogating
>> energy as two paths to go down, and it will (initially) go both ways in
>> about an equal amount.
>
> Maybe you should review what you actually stated in the context of
> current surge supression discussion:
> "
> "The MOVs will act like conductors when they are clamping. The surge
> will
> |> |> take both paths ... the path through the MOVs, and the path
> going past the
> |> |> MOVs. In general, about 50% will go each way. That can vary at
> higher
> |> |> frequencies. "
>
> That sure sounds like 50% of the surge is going through the MOV and
> the other 50% is going on past it to the protected equipment.
>
> And that I would have to agree with Bud on, it's phantasy physics,
> because if it were true, no type of surge protection would work,
> because it would only be 50% effective.

He is using transmission line effects which Martzloff investigated and
said do not come into play unless the circuit is 200m long. Phil claims
high frequencies.

Still missing - a source that supports nanosecond risetimes and 100MHz
spectrum.

--
bud--

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