Surge / Ground / Lightning
in [Home Built PC]
|
From: phil-news-nospam on 5 May 2008 18:48 In alt.engineering.electrical bud-- <remove.budnews(a)isp.com> wrote: | phil-news-nospam(a)ipal.net wrote: |> In alt.tv.tech.hdtv bud-- <remove.budnews(a)isp.com> wrote: |> |> | Previously you said Martzloff "flubbed the experiment". |> |> I remember that. You were telling me about some information he had |> obtained from some experiment. |> |> | Now you agree with Martzloff that branch circuit must be 200m for |> | transmission line behavior with 1.2 microsecond rise time. |> |> That's not a result of an experiment. | | "*From this first test*, we can draw the conclusion (predictable, but | too often not recognized in qualitative discussions of reflections in | wiring systems) that it is not appropriate to apply classical | transmission line concepts to wiring systems if ..." | | As usual, you don?t know what was written. What what kind of surge did Martzloff use to carry out that test? |> I'm not so sure the exact distance |> is 200m for that exact rise time. But that is a subjective thing. | | Quit equivocating. Where is your cite. Like for nanosecond risetimes. Observation. |> | You say that doesn't apply because surges are faster. Martzloff uses 1.2 |> | us because that is a standard rise time for surges produced by lightning |> | as defined in IEEE standards. |> |> Martzloff did not say that was a defined standard in the statement you |> quoted. He just used it as an example to come up with the 200m figure. | | He used it because 1.2/50 (voltage) is an IEEE standard. The 8us from | w_?s engineer is another standard (8/20 current). The standard for what? The typical surge? |> | w_' professional engineer source says 8 micoseconds with most of the |> | spectrum under 100kHz. |> |> Even with 1 nanosecond rise time, most of the energy will be present in |> the spectrum below 100 kHz. That means nothing when the surge is strong |> enough to have energy above some frequency that is relevant to the whole |> system involved that can do damage. That frequency might be 100 Mhz for |> some thing, and 1 GHz for other things. | | Still missing ? your source. Nanosecond risetime. 100MHz spectrum. Observation. Of course this is a concept you cannot understand. |> | You still have *no sources that support your belief* that risetimes are |> | far faster. |> |> I have experience and observation for that. I need no more. | | Lots of people have experience and observation with flying saucers. | | The rest of us want a source. The only flying saucers I have seen are the ones I've tossed. -- |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) |
From: Mike Tomlinson on 6 May 2008 17:01 In article <88722$4820876c$4213ea45$31115(a)DIALUPUSA.NET>, bud-- <remove.budnews(a)isp.com> writes >Martzloff has written "the impedance of the grounding >system to 'true earth' is far less important than the integrity of the >bonding of the various parts of the grounding system." Indeed. This is an important principle of the UK wiring code. It's referred to as "equipotential bonding." Such a concept, of course, would be far beyond the understanding of w_'s lone brain cell. -- (\__/) Bunny says NO to Windows Vista! (='.'=) http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.html (")_(") http://www.cypherpunks.to/~peter/vista.pdf
From: Mike Tomlinson on 6 May 2008 17:04 In article <8fa76$482087fc$4213ea45$31115(a)DIALUPUSA.NET>, bud-- <remove.budnews(a)isp.com> writes >Last I heard UK phone entry protectors did not clamp the voltage to >earth. You're quite correct. It's a practice that the GPO (forerunner to British Telecom) abandoned in the 1960s, showing how up to date w_'s "knowledge" is. -- (\__/) Bunny says NO to Windows Vista! (='.'=) http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.html (")_(") http://www.cypherpunks.to/~peter/vista.pdf
From: Boden on 5 May 2008 20:02 bud-- wrote: > phil-news-nospam(a)ipal.net wrote: > >> In alt.tv.tech.hdtv bud-- <remove.budnews(a)isp.com> wrote: >> >> | The last standards for simulating typical surge waveforms I have >> seen | (IEEE) were >> | 1.2 us rise time, 50 us duration >> | 8 us rise time, 20 us duration >> | a ring wave with a frequency about 100kHz. >> >> So now you are saying these figures represent a typical surge waveform, >> as opposed to the worst case waveform you said a long time ago. > > > Still missing - your source that indicates nanosecond rise times and > 100MHz spectrum. > >> >> What does the "/" mean in that case, anyway? I never got to ask you that >> before. Does it mean "divide 1.2 by 50"? > > > It is standard notation in the surge field. 1.2 us risetime and 50 us > duration > Sloppy notation.
From: krw on 5 May 2008 20:40
In article <fvo6qr11f4i(a)enews1.newsguy.com>, Boden(a)tidewater.net says... > bud-- wrote: > > > phil-news-nospam(a)ipal.net wrote: > > > >> In alt.tv.tech.hdtv bud-- <remove.budnews(a)isp.com> wrote: > >> > >> | The last standards for simulating typical surge waveforms I have > >> seen | (IEEE) were > >> | 1.2 us rise time, 50 us duration > >> | 8 us rise time, 20 us duration > >> | a ring wave with a frequency about 100kHz. > >> > >> So now you are saying these figures represent a typical surge waveform, > >> as opposed to the worst case waveform you said a long time ago. > > > > > > Still missing - your source that indicates nanosecond rise times and > > 100MHz spectrum. > > > >> > >> What does the "/" mean in that case, anyway? I never got to ask you that > >> before. Does it mean "divide 1.2 by 50"? > > > > > > It is standard notation in the surge field. 1.2 us risetime and 50 us > > duration > > > Sloppy notation. s/sloppy/concise/ -- Keith |