On Saturday, October 24, 2015 at 1:24:01 PM UTC-4, westom wrote:
On Saturday, October 24, 2015 at 12:32:37 PM UTC-4, trader_4 wrote:
BS. The IEEE guide clearly says so.
trader_4 has no idea what it says. He takes sentences out of context.
Woooah Pilgrim. I take sentences out of context? I've given you
entire paragraphs and more importantly I've given links to the
actual documents at IEEE and NIST, complete with page reference.
Remember that last part.
Many completely different surges are summarized. One that is tiny (typically cause no damage) is connected on a safety ground back to the breaker box. A completely different and destructive transient is why a connection must be to earth AND must be low impedance. Why do so many professionals require that low impedance connection if safety ground wires are sufficient? Because trader_4 misreads. He intentionally ignores some paragraphs to lie.
Multiple Martzloff papers, the AT&T forum, IEEE Red and Emerald Books, and ... how many other professional sources were cited? He ignored them all.
I haven't ignored a single one, it's just that you rarely provide
a link to your alleged sources. Case in point, I asked WTF the "ATT Forum"
even is. It sounds like some newsgroup or similar.
Why do we know he is lying? Where does he even cite one specification number? He doesn't.
What specification number exactly would you like? I did cite numbers
where appropriate, like to show you that the IEEE guide says that the
worst case surge arriving at a panel is ~10KA.
Like an extremist politician, he only makes subjective declarations - with disparaging commentary.
Sigh, I've cited NIST, IEEE. It doesn't get any more credible than that.
He intentionally ignores these from his own citations:
An effective, low-impedance ground path is critical
for the successful operation of an SPD. High surge
currents impinging on a power distribution system
having a relatively high grounding resistance can
create enormous ground potential rises, resulting in
damage. Therefore, an evaluation of the service
entrance grounding system at the time of the SPD
installation is very important.
SPD is his surge protection device.
My surge protection device? Clearly what they are
talking about though is a surge
protector at the panel. And again, everyone could quickly see
WTF you're citing, in context, if you simply provided the page
numbers, etc. But you think by not doing that, you can misrepresent
and get away with it. Not here, not today.
trader_4 knows he can ignore that requirement.
Safety ground is not earth ground. Wire impedance is excessive. From his own citation:
To achieve optimum overvoltage protection, the
connecting leads between the SPDs and the panel or
protected equipment should be as short as possible
and without sharp 90-degree bends. ...
The inductance of the wire is the determining factor
rather than the resistance of the wire. The inductance
is a function of the length and the loop area of the
circuit including the SPD.
That inductance obviously creates a high impedance meanning a plug-in protector is all but disconnected from what harmelessly absorbs a surge. Or return to numbers posted eariler. trader_4 know honesty need not provides numbers.
Where are the numbers in all *your* blather in this post so far?
And again, in the above, they are talking about surge protection
at the panel. In the same documents they go have similar sections
that talk about using plug-in surge protectors too. BTW, if that
plug-in is all but cut off from the outside world, how exactly does
the big, bad surge get there? Again, unidirectional impedance in
your alternate universe.
A wall receptacle safety ground will magically earth a tiny 100 amp surge? That wire is less than 0.2 ohms resistance. And maybe 120 ohms impedance. 100 amps times 120 ohms is 12,000 volts. That receptacle (and protector and adjacent appliances) are at less than 12,000 volts. Where is the protection?
If the impedance is all so mighty, how exactly did the 100A arrive
at the receptacle? Again, in WToms world impedance only counts in
one direction when he's talking about the return path to earth. But
the forward path, from the utility pole to the receptacle, that must
have zero impedance.....
How ironic. Figure 8 page 33 shows similar. Because impedance on a safety ground wire is excessive, then a protector could not connect to earth as trader_4 claims. It earths a surge through a nearby TV - 8000 volts destructively. Which one would expect when that 120 ohms impedance exists. Those damning numbers again.
Oh my, now we have "damning numbers". Are they like imaginary ones?
But it's good that you cited the page this time. That way everyone can
quickly go there and see that as part of Figure 8 it says:
"A second multi-port protector as shown in Fig. 7 is required to protect TV2."
He also ignored this:
One of the main functions of the service entrance SPD is
to reduce the surge current reaching any downstream
protectors
Please show us where I ever ignored that. I said from the first posts
that a tiered strategy is preferred. Even years ago, I told you that
is *exactly* what they do in a Telco facility. The lines are protected
where they enter the building and they also have protection on the line
cards in the equipment itself. Of course you denied that. I even pulled
up app notes for designers that showed them being used.
Of course ... for many reasons. That downstream (plug-in, point of connection) protector is not designed for a type of surge that typically causes damage. Again, trader_4 has no idea of relevant concepts such as longitudinal and transverse currents. He does not even try to demonstrate basic electrical knowledge.
http://www.lightningsafety.com/nlsi_lhm/IEEE_Guide.pdf
IEEE guide. Page 32, fig 7
It shows a multi-port surge protector being used and states:
"The multiport protector shown at the TV set can greatly decrease
the voltage between the AC ground and the coax cable, preventing
damage to the set."
page 33, fig 8
"A second multi-port protector as shown in Fig. 7 is required to protect TV2."
That downstream protector must somehow only absorb hundreds of joules. And then another problem often seen when a 'whole house' protector is not reducing currents reaching downstream protectors ... fire. Another problem that trader_4 repeatedly denied.
Take it up with the engineers at IEEE, NIST, etc.
trader_4 is not honest. He only posted here to attack me.
Yes, that's what I decided to do. Yesterday, I thought, gee, we haven't
heard from loony WTom for a year or so. I should attack him. Funny thing,
though how you made the first couple of posts, before I said anything.
YOU were going back and forth with Clare, who was disagreeing with you.
It was only when your usual level of total BS emerged that I decided
to take you to the woodshed *again* for a right proper whooping.
Apparently he does same to others. He cherry picks sentences to distort what professionals say.
I distort?
Martzloff in his own words:
http://pml.nist.gov/spd-anthology/fi...es_happen!.pdf
"Plug-in Surge Protectors
This is the easiest solution and there are a wide variety of brands
in the stores. These come in two forms: a box that plugs directly
into a wall receptacle or a strip with a power cord and multiple outlets."
And you're here trying to tell us that he really said they cause
damage, should never be used, can't work, etc.
Clearly does not know how electricity works. He never posts claims with numbers - as any honest person would.
Interesting argument, given that the only numbers you have given
in the entire post are hypothetical ones, that you just made up:
"a tiny 100 amp surge? That wire is less than 0.2 ohms resistance. And maybe 120 ohms impedance. 100 amps times 120 ohms is 12,000 volts."
Or do you mean numbers like "page 33, Fig 8", which when viewers
look will see that it doesn't say what you claim and that it ends with:
"A second multi-port protector as shown in Fig. 7 is required to protect TV2."