Surge protectors to use with home electronics when grounding

[John Fields]

On Mon, 14 Jul 2008 10:12:25 -0700 (PDT), w_tom <w_tom1@usa.net>
wrote:

On Jul 14, 11:20 am, John Fields <jfie...@austininstruments.com
wrote:
What you're doing is confusing the MOV's ratings with their resistance
at a particular current.

As I noted earlier, and which you conveniently failed to address, is
that an MOV rated higher in energy absorption capability than another
will have a lower resistance for the same current through it because
of its larger volume of conductive material.

That larger volume is what gives it a higher energy rating in that it
will take more energy to heat it to destruction, which is what this is
all about.

John is now saying what I posted.

---
You're a liar.

What you posted was that since a 1000 joule MOV only absorbs 75 joules
while a 100 joule absorbs 100 joules for the same transient the 1000
joule transient is a better protector because it shunted 25 joules
more than the 100 joule unit to ground, which is pure insanity.

The 1000 joule is a better protector because it can take more hits for
longer than the 100 joule unit. The fact that it absorbs less energy
than the 100 joule unit for the same hit is serendipitous and largely
unimportant.
---

Are you now admitting what an MOV's function is?
Not to absorb more surge energy. The purpose of
an MOV is to absorb less surge energy AND to divert more surge energy
into earth.

---
The function of an MOV is to provide a low-impedance path to an
electrical current once a certain voltage has been reached. Whether
it's to earth or not is immaterial to this thread which is about using
surge protectors when no ground is available.
---

Protection is about shunting tens of thousands of joules
into earth through a 100 joule MOV while having that protector
undamaged.

---
Because of the mechanics of MOVs, it's impossible for them to be
undamaged once they're put into service and start absorbing energy.
---

How does a wire - that absorbs energy - conduct more energy
elsewhere? Wire volume increases. How does an MOV provide protection
by conducting more energy elsewhere? MOV volume increases.

---
Which is what you learned from me and are now trying to pretend you
knew all along.

LOL, I've wasted way too much time on you already.

JF

 

[bud--]

w_tom wrote:

Does the NIST not make it blunt enough
for you?
..

What does the NIST guide really say?
Plug-in suppressors are the "easiest solution".
w_ is fond of distorting what everyone says.
..

John says:
So where is that plug-in protector numeric spec that lists
each type of surge and protection from that surge?
If they're UL listed that'll be given in UL1449.

UL does not care whether a protector provides protection. UL only
cares that a protector does not kill humans or burn down the house.
..

There are multiple tests to pass UL1449. One of the early ones is a
series of 20 surges. The suppressor can not fail during that test.

The suppressor can fail later. For example when subjected to long
overvoltage a suppressor can fail safely. (MOVs are good at very high
currents for very short duration (surge) but not long duration.)

Contrary to w_'s delusions, UL1449 includes tests to assure suppressors
(both plug-in and service panel) have protection functionality.
..

No plug-in protector claims to provide protection. John Fields also
does not post such protection numbers.
..

But I did. Long ago.
..

No earth ground means no effective protection.
..

Poor w_ thinks his religious mantra will protect him from the heathens
than abound in this newsgroup. Sorry w_, it isn’t working.

Poor w_ still can’t find a link to another lunatic that agrees that
plug-in suppressors are NOT effective.

And poor w_ still can’t answer embarrassing 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"?
- How would a service panel suppressor provide any protection in the
IEEE example, pdf page 42?
- Why does the IEEE guide say in the example "the only effective way of
protecting the equipment is to use a multiport protector"?
- Why does SquareD say "electronic equipment may need additional
protection by installing plug-in [suppressors] at the point of use."
– How can SquareD be a "responsible" company when there is no "spec that
lists each type of surge and protection from that surge".
- Where is the link to a 75,000A and 1475Joule rated MOV for $0.10.
- Why does w_ get no respect in a science newsgroup?

--
bud--

 

[Michael A. Terrell]

w_tom wrote:

On Jul 15, 12:13 pm, bud-- <remove.budn...@isp.com> wrote:
What does the NIST guide really say?
Plug-in suppressors are the "easiest solution".
...
There are multiple tests to pass UL1449. One of the early ones is a
series of 20 surges. The suppressor can not fail during that test.

The suppressor can fail later. For example when subjected to long
overvoltage a suppressor can fail safely. (MOVs are good at very high
currents for very short duration (surge) but not long duration.)

The guide says plug-in protectors are an easiest solution. Then the
guide says why the easiest solutoin does not provide effective
protection. A sales promoter routinely forgets what is on Page 42
Figure 8. A protector too close to appliances and without earth
ground may even earth a surge 8000 volts destructively through
adjacent TV. That surge energy must be earthed or that surge energy
will be inside the house finding other paths to earth. Bud tells us
'clamping to nothing' makes surge energy disappear. Profits are at
risk.

A protector is only as effective as its earth ground. But ignores
that part to make half truth claims: a plug-in protector is an
easiest solution. He forgets the other part. A plug-in protector
does not even claim, in numeric specs, to provide protection. It is a
protector but it does not even claim protection from the typically
destructive surge. Did Bud also forget that other part? No numeric
specs claim protection.

A protector can fail during UL1449 tests and still get UL
registered. UL does not care whether a protector does protection. UL
is only concerned that it does not burn down the house. So, a
grossly undersized plug-in protector disconnects protector circuits
faster. If that thermal fuse not trip fast enough, scary pictures
exist:
http://www.hanford.gov/rl/?page=556&parent=554
http://www.westwhitelandfire.com/Articles/Surge%20Protectors.pdf
http://www.ddxg.net/old/surge_protectors.htm
http://www.zerosurge.com/HTML/movs.html
http://tinyurl.com/3x73ol
http://www3.cw56.com/news/articles/local/BO63312/

If a grossly undersized protector completely fails even on the
tiniest of surges (as indicated by that OK light), then the naive
consumer will say "My surge protector sacrificed itself to save my
computer". Nonsense. Protection inside every computer saved that
computer. Plug-in protector disconnected its protection as fast as
possible to avoid those scary pictures.

UL does not care whether a protector provides any protection.
Protector circuits can disconnect ASAP - provide no protection - and
still obtain UL approval. UL's only concern is human life - not surge
protection. Threats to electronics are irrelevant. Protector can
completely fail and still get a UL1449 approval - as long as it does
not create those scary pictures during UL tests.

Sometimes the emergency backup circuit does not disconnect protector
fast enough. Most every fire company has seen what then results -
those scary pictures. Best is to install one properly sized and
properly earth 'whole house' protector. Have effective protection,
save money, and don't have those scary pictures. Have what even the
IEEE recommends - once we get facts that Bud ignores.

Sure follow Tom's advice and continue to have equipment destroyed by
surges from other sources. He is a meat popsicle, dead from the neck
up. He is the ultimate USENET idiot troll. He doesn't understand basic
physics or even basic electronics. Transmission lines? No way! The
difference between shunt and adsorb? He has no clue. Ungrounded
circuits? He still has no clue. Clear thoughts? He's ever had one on
the subject.


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sheep.

 

[w_tom]

On Jul 15, 12:13 pm, bud-- <remove.budn...@isp.com> wrote:

What does the NIST guide really say?
Plug-in suppressors are the "easiest solution".
...
There are multiple tests to pass UL1449. One of the early ones is a
series of 20 surges. The suppressor can not fail during that test.

The suppressor can fail later. For example when subjected to long
overvoltage a suppressor can fail safely. (MOVs are good at very high
currents for very short duration (surge) but not long duration.)

The guide says plug-in protectors are an easiest solution. Then the
guide says why the easiest solutoin does not provide effective
protection. A sales promoter routinely forgets what is on Page 42
Figure 8. A protector too close to appliances and without earth
ground may even earth a surge 8000 volts destructively through
adjacent TV. That surge energy must be earthed or that surge energy
will be inside the house finding other paths to earth. Bud tells us
'clamping to nothing' makes surge energy disappear. Profits are at
risk.

A protector is only as effective as its earth ground. But ignores
that part to make half truth claims: a plug-in protector is an
easiest solution. He forgets the other part. A plug-in protector
does not even claim, in numeric specs, to provide protection. It is a
protector but it does not even claim protection from the typically
destructive surge. Did Bud also forget that other part? No numeric
specs claim protection.

A protector can fail during UL1449 tests and still get UL
registered. UL does not care whether a protector does protection. UL
is only concerned that it does not burn down the house. So, a
grossly undersized plug-in protector disconnects protector circuits
faster. If that thermal fuse not trip fast enough, scary pictures
exist:
http://www.hanford.gov/rl/?page=556&parent=554
http://www.westwhitelandfire.com/Articles/Surge%20Protectors.pdf
http://www.ddxg.net/old/surge_protectors.htm
http://www.zerosurge.com/HTML/movs.html
http://tinyurl.com/3x73ol
http://www3.cw56.com/news/articles/local/BO63312/

If a grossly undersized protector completely fails even on the
tiniest of surges (as indicated by that OK light), then the naive
consumer will say "My surge protector sacrificed itself to save my
computer". Nonsense. Protection inside every computer saved that
computer. Plug-in protector disconnected its protection as fast as
possible to avoid those scary pictures.

UL does not care whether a protector provides any protection.
Protector circuits can disconnect ASAP - provide no protection - and
still obtain UL approval. UL's only concern is human life - not surge
protection. Threats to electronics are irrelevant. Protector can
completely fail and still get a UL1449 approval - as long as it does
not create those scary pictures during UL tests.

Sometimes the emergency backup circuit does not disconnect protector
fast enough. Most every fire company has seen what then results -
those scary pictures. Best is to install one properly sized and
properly earth 'whole house' protector. Have effective protection,
save money, and don't have those scary pictures. Have what even the
IEEE recommends - once we get facts that Bud ignores.

 

[bud--]

w_tom wrote:

On Jul 15, 12:13 pm, bud-- <remove.budn...@isp.com> wrote:
What does the NIST guide really say?
Plug-in suppressors are the "easiest solution".

The guide says plug-in protectors are an easiest solution. Then the
guide says why the easiest solutoin does not provide effective
protection.
..

Poor w_. He probably really believes that.
..

A protector is only as effective as its earth ground.
..

The required statement of religious belief in earthing.
..

No numeric
specs claim protection.
..

Provided long ago. Poor w_ just repeats all the same lies - a la Goebbels.

But poor w_ still can’t find a link to another lunatic that agrees that
plug-in suppressors are NOT effective. Even on the internet no one is
as stupid.

And poor w_ still can’t answer embarrassing 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"?
- How would a service panel suppressor provide any protection in the
IEEE example, pdf page 42?
- Why does the IEEE guide say in the example "the only effective way of
protecting the equipment is to use a multiport protector"?
- Why does SquareD say "electronic equipment may need additional
protection by installing plug-in [suppressors] at the point of use."
– How can SquareD be a "responsible" company when there is no "spec that
lists each type of surge and protection from that surge".
- Where is the link to a 75,000A and 1475Joule rated MOV for $0.10.
- Why does w_ get no respect in a science newsgroup?

--
bud--

 

[Michael A. Terrell]

w_tom wrote:

On Jul 16, 12:47 pm, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
Sure follow Tom's advice and continue to have equipment destroyed by
surges from other sources. He is a meat popsicle, dead from the neck
up. He is the ultimate USENET idiot troll. He doesn't understand basic
physics or even basic electronics. Transmission lines? No way!

Where does Michael Terrell post a solution for the OP? He does not.
Michael will attack one who has exposed him previously as technically
naive. Michael cannot provide the OP with a solution. That requires
knowledge and experience. Michael does not even try to post a
solution. Michael remembers being exposed for not understanding some
basic electrical concepts.

Still halucinating,. Tommy?

Dissipating surge energy harmlessly in
earth? Also too complex. Transmissions lines - characteristic
impedance - is also totally irrelevant to surge protection and the
OP's question.

Only if you don't understand it, Tommy. In the real world it does
matter.

An electrically knowledgeable Michael would have known that.

How many posts by salesman and TV repairmen without a solution for
the OP?

More lies, Tommy? Yes I did repair TVs when I was in Junior high
school. A lot of people did, back in the '60s. WhatI learned there, and
from a couple corespondence courses let me test out of a three year
course at Ft Monmoth for Broadcast Engineer. I was also able to repair
some microwave communications equipment, RADAR, and CATV harware while
in the US Army. I went on to work at other radio & TV stations, and to
build communications equipment for NASA, NOAA, and the European Space
Agency. All yo eaver do is slander people. YOU NEVER OFFER ANY VALID
ADVICE.


There is a lot of liability involved with any modification of any
alarm equipment. We looked into marketing a simple alarm circuit in
1975, and we were told we needed a minimum of $10,000,000 insurance
before we sold the first unit. Some people sold home brew and modified
equipment, and lost their ass when something went wrong.


The solution has to be either external to the panel, or use a better
panel. I already stated that shielded, twisted pair cable is a solution
for some problems, but all you do is whine and tell lie after lie.
Twisted pair wire was the standard back in the early '70s, but a lot of
systems are installed with two conductor, jacketed cable these days. It
has no twist, letting it pick up RF and induced electrical noise. You
don't know a damn thing, but you TRY to present yourself as an expert.

You slander people who have worked with the equipment. I was in the
business when the first MPU based alarm panel was introduced. It was in
a beautiful extruded aluminum case and used the RCA 1802 processor, but
was very overpriced. The programmer was over $1000 and had a six month
waiting list, so the system never caught on in my area. That panel would
have doubled the material cost for any job it was used on.

I made tapes for Ademco and Napco tape dialers, programmed 82S23
memory ICs for the first digital dialers, and installed equipment from
long gone alarm companies. Ever see Moose, FBI or any other '70s
hardware? How about the first PIR detector with a lithium battery?
They claimed it would last 10 years, but it failed in five minutes on
our showroom display. The small VMOS FET shorted out. Ever see a
Frankin central station receiver? Ever face down someone you caught red
handed trying to break into a machine shop with one of your systems?
How about install a system in a bank or credit union? Have you ever
done anything other than whine, and tell lies?


--
http://improve-usenet.org/index.html

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm

Sporadic E is the Earth's aluminum foil beanie for the 'global warming'
sheep.

 

[w_tom]

On Jul 16, 12:47 pm, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:

   Sure follow Tom's advice and continue to have equipment destroyed by
surges from other sources.  He is a meat popsicle, dead from the neck
up.  He is the ultimate USENET idiot troll. He doesn't understand basic
physics or even basic electronics. Transmission lines?  No way!  

Where does Michael Terrell post a solution for the OP? He does not.
Michael will attack one who has exposed him previously as technically
naive. Michael cannot provide the OP with a solution. That requires
knowledge and experience. Michael does not even try to post a
solution. Michael remembers being exposed for not understanding some
basic electrical concepts. Dissipating surge energy harmlessly in
earth? Also too complex. Transmissions lines - characteristic
impedance - is also totally irrelevant to surge protection and the
OP's question. An electrically knowledgeable Michael would have known
that.

How many posts by salesman and TV repairmen without a solution for
the OP?

 

[John Fields]

On Mon, 30 Jun 2008 12:09:51 -0700 (PDT), w_tom <w_tom1@usa.net>
wrote:

On Jun 29, 8:43 pm, John Fields <jfie...@austininstruments.com> wrote:
Nothing of any consequence.

So John, where is any professional citation that says characteristic
impedance is relevant? Nothing.

Where is this professional citation that says common mode surges -
what lightning creates - are not typically destructive surges?
Nothing.

Where is this professional citation that says a hot to neutral surge
is not eliminated (reduced) by that same one 'whole house' protector?
Nothing.

Why is a peer reviewed front page article in a highly regarded
electrical engineering publication not relevant? Its title:
"Protecting Electrical Devices from Lightning Transients". John
somehow knows industry professionals are wrong?

You have even confused characteristic impedance with wire impedance.
Why do you ignore wire impedance and discuss irrelevant wire
resistance? Your denials are based only in insults?

Why does every telco install 'whole house' protectors and not waste
money on plug-in protectors? For better protection, why do telcos
locate protectors distant from electronics - up to 50 meters? For
better protection, why do telcos install even better earthing and
connect 'whole house' protectors as short as practicable to that
earthing? John says telcos are also loony?

And where is that plug-in protector spec that claims protection?
Oh. No plug-in protector will list protection from each type of
surge. But you know that plug-in protector is effective?

Where does John Fields post a solution for the OP whose building
only has two wire receptacles? You provide no useful answers.

OP's solution is simple, more effective, and less expensive than
plug-in protectors. Similar to a solution implemented by all telcos,
commercial broadcasters, rocket launch facilities, and military
bases. A 'whole house' protector with breaker box earthing is
upgraded to post 1990 National Electrical Code standards. Complete
surge protection installed for about $1 per protected appliance.

Why does John Fields recommend using three wire power strip
protectors on two wire receptacles? How do John's insults prove
science or assist the OP? John even denies lightning creates common
mode surges. A protector is only as effective as its earth ground as
noted by numerous above and responsible sources. Meanwhile, the OP
cannot use plug-in protectors. His best solution is the standard
solution used everywhere when surge damage is not acceptable.

---
Well, I see from your outburst that you've been confounded by my
excellent ASCII art schematics and my lucid explanation of why and how
two-wire plug-in TVS-based surge suppressors can be used to good
advantage in premises without (or with unused) earth grounding.

That is, after all, the topic as indicated by the subject line.

If you'd like to discuss whole-house surge protection I suggest you
start another thread with a subject which reflects that topic

I also realize from your questions (which you pose as sarcastic
challenges) that you don't understand the subject matter involved and
hope that I'll "vindicate" myself by coming back with answers which
you can then study up on and pretend you knew them all along, as
you've done with "common mode" and "characteristic impedance".

Sorry, Charlie, I don't play that way.

JF

 

[w_tom]

On Jun 30, 4:06 pm, John Fields <jfie...@austininstruments.com> wrote:

Well, I see from your outburst that you've been confounded by my
excellent ASCII art schematics and my lucid explanation of why and how
two-wire plug-in TVS-basedsurgesuppressors can be used to good
advantage in premises without (or with unused) earth grounding.
That is, after all, the topic as indicated by the subject line.

Every responsible source says the grounding must exist. No surge
protection stops or absorbs the common mode surge - surge that
typically causes appliance damage. As Bud's NIST states:

... 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.

*Diverting*. Your ASCII protector has all but no earth ground.
Excessive wire impedance. Nothing to divert to. Protector is the same
problem demonstrated in Bud's other citation. Page 42 Figure 8 - a
protector too far from earth ground and too close to appliances
therefore leaves surge energy earthed 8000 volts destructivley through
an adjacent TV.

No way around what a protector does. Either it stops (absorbs)
surge energy OR is diverts (shunts, connects, clamps) that surge
energy into earth. A destructive surge will increase voltage. as
necessary, to connect to earth - Page 42 Figure 8. Stopping
(absorbing) surge energy is not effective protection. Your ASCII
circuit protector with excessive wire impedance must absorb all surge
energy (impossible) or divert a surge destructively via household
appliances - Page 42 Figure 8.

The OP need not rewire the house. But no way around what provides
effective protection. As every responsible source notes, that service
entrance earth ground must exist for the same reasons earthing exists
in every telco facility. One 'whole house' protector means everything
is protected. Protection that your ASCII circuit does not provide.

As even Sun Microsystems notes in their Planning guide for Sun
Server room:

Section 6.4.7 Lightning Protection:
Lightning surges cannot be stopped, but they can be diverted.
The plans for the data center should be thoroughly reviewed
to identify any paths for surge entry into the data center.
Surge arrestors can be designed into the system to help
mitigate the potential for lightning damage within the data
center. These should divert the power of the surge by providing
a path to ground for the surge energy.

Who should the OP believe? John Fields? Or Sun Microsystems ...
and the IEEE, NIST, US Air Force, QST (the ARRL), Dr Kenneth
Schneider, Electrical Engineering Times, Schmidt Consulting,
Polyphaser's highly regarded application notes, a station engineer
from WXIA-TV, ...

Effective protectors work by earthing surges. That wall receptacle
wire is woefully too long, has sharp bends, had splices, is bundled
with other wires, etc. Each point conspires to make it only a safety
ground (equipment ground) and not earth ground.

Even Martzloff describes what would happen with your ASCII circuit:

Conclusion
1) Quantitative measurements in the Upside-Down house clearly
show objectionable difference in reference voltages. These occur
even when or perhaps because, surge protective devices are
present at the point of connection of appliances.

An MOV protects by becoming more conductive? What happens when a
surge protector has even higher joules numbers? Then the protector
absorbs even less surge energy. A better protector (higher joules)
absorbs less surge energy - what is desirable. MOVs don't protect by
absorbing surges - which is why a Wikipedia citation on joules was
irrelevant. MOVs protect by diverting energy elsewhere - earth
ground.

John do you really believe a hundred joules in a UPS or power strip
will stop (by absorbing) lightning energy? Do you know how tiny 200
joules is? Where is protection from a 200 joule MOV?

Both wire and MOVs absorb some energy while shunted massive energy
elsewhere. A 200 joule protector is expected to shunt maybe 2000 or
50,000 joules into earth (20,000 amps) Whereas the MOV may absorb 200
joules, earth must dissipate thousands of joules. Better protectors
work more like wires - shunting more energy while dissipating even
less - or why your Wikipedia citation makes no sense.

What is wrong with ASCII diagrams? First, you promote wire
resistance that is irrelevant. Your 14 AWG wire at 0.15 ohms
resistance is also something like 130 ohms impedance. (Not
characteristic impedance with is something completely different).

Second, your 1000 volts surge at a transformer is made completely
irrelevant by protection required inside all computers. All computers
are required to withstand 1000 volt transients. Many have internal
protection that means even higher voltages without damage. That
transformer surge voltage will be lower at appliances. No problem.
Electronics routinely withstand 600 volt transients without damage - a
standard from 1970.

Third, surges are current events - not voltage. Tiny surges are 100
amps (not 8 amps). Serious surges are thousands of amps. Effective
'whole house' protectors must earth tens of thousands of amps so that
voltages at all appliances remain below 600 volts. Again, why high
reliable facilities use 'whole house' protectors and don't use your
point of use protection.

Fourth, any attempt to stop or absorb surge energy means voltages
rise as much as necessary to blow through that blockage. Voltage will
rise as high as necessary to connect that current to earth. Lightning
makes the most non-conductive material (air) into miles of conductor.
Nothing stops (absorbs) the typically destructive surge that seeks
earth ground. Effective protection *diverts* surges to earth on non-
destructive paths. Which does your ASCII protector do? Divert that
energy into earth or absorb it. Which one? Surge protection is about
earthing (diverting) before surge energy can enter a building.

Fifth, if a designer who used MOVs, then you would have accurate
numbers. One milliamp through your 150v MOV puts it at just above
200 volts. Your 150 volt MOV does not conduct at 150 volts. Serious
surge currents start with the 150 volt MOV at around 300 volts. John
Fields - your ASCII circuit description violates every number in this
paragraph. No MOV is installed to keep appliance voltage at 150 volts
as you posted. You would know that had you designed protectors and
studied V-I charts for MOVs. You don't even know how MOVs work.

Sixth - clamping the hot and neutral wire means surge energy remains
on both wires - unclamped - still seeking earth ground. Assume all 8
amps of a near zero (non-destructive) surge used the neutral wire to
obtain earth: that protector is at maybe 540 volts (not 150 volts).
A nondestructive surge because an 8 amp surge is too trivial to
overwhelm protection typically in all electronics. Your circuit only
works for a type of surge that typically does not do damage AND fails
- provides no protection - for the type of surge that does cause
appliance damage. A destructive surge means energy remains on that
hot and neutral wire, still seeking earth ground, and maybe finding
earth 8000 volts destructively via some appliance. Page 42 Figure 8
demonstrates this.

Your ASCII circuit protects from a surge (measured in voltage) that
is not destructive, has trivial energy, made further irrelevant by one
'whole house' protector, and that does not represent what effective
protectors are designed to eliminate. Destructive surges are not a
trivial 8 amps and defined by wire resistance. Your 150v MOV does not
clamp at 150 volts. Your example even demonstrates no knowledge of
MOV datasheets. Numerous additional technical problems with your
ASCII circuit. John - you don't even know the V-I curves for MOVs.
You have never designed this stuff let alone test it.

Why do telcos not use your ASCII circuit? Telcos have the exact
same surge problem AND must never suffer surge damage. Same problem
and solution applies to every high reliability facility. To avoid how
surge protection works, you simply pretend telcos don't suffer
surges? Nonsense. I designed this stuff that was tested by direct
lightning strikes. You clearly never did design (as demonstrated by
your 150v MOV conducting current at 150 volts). Protection now
required in every home is how ham radio operators did it 80 years ago.
Your protection circuit violated what hams knew 80 years ago.

What you should have known. That 150v MOV has 150 volts across it
when conducting how much current? Less than 1 milliamp. Why did you
not know what every protector designer would know? Take a 200 joule
MOV (V151CA32). What is that 150v MOV voltage when conducting an 8
amp surge? About 360 volts (not 150 volts). Why am I quoting from a
V-I chart that you clearly never read? How do you know what that MOV
does when you assume rather than read datasheets? That is the point.
Worse. John - you still discuss what is irrelevant (wire resistance)
and ignore what responsible engineering sources discuss (wire
impedance).

How critical is wire impedance? Manufacturers even define wire
impedance in that two inch MOV lead for test purposes. Where a tester
connects to an MOV's leads changes MOV electrical responses. Why?
Wire impedance (not wire resistance) is important even in manufacturer
application notes. To post accurately, John would also know this:

Varistors: Ideal Solution to Surge Protection by Bruno van Beneden
In conventional leaded devices, the inductance of the lead
can slow the fast action of the varistor to the extent that
protection is negated.

Just another source that demonstrates wire impedance - not resistance
- for protection. Even inductance in MOV wire leads can degrade
protection because impedance (not resistance) is the critical
parameter.

John, your ASCII circuit cites wire resistance which is irrelevant
(as so many sources state) AND demonstrates design ignorance of how
MOVs work. You don't even know MOV voltage when conducting a trivial
8 amps. Glaring, obvious, and unacceptable mistakes in your ASCII
circuit. A mistake that exists due to no protector design experience.

Protection is about earthing. The effective protector must make a
short (low impedance) connection to earth - as every responsible
source says and John denies. Voltages between wires is trivial.
Voltages (and more important - current) between each wire and earth
defines surge protection. One effective protector means earthing even
ten thousand amps to earth - without damage.

John - I only listed simplest mistakes in your ASCII protector
circuit. More exist. But you don't even know the most basic numbers
or a V-I chart for MOVs. You still confuse irrelevant resistance with
what so many other sources discuss? Wire impedance.

Why do sharp bends cause further compromise surge protection? Sharp
bends don't affect wire resistance and increases wire impedance. So
why do you still discuss resistance?