Re: Surge protectors to use with home electronics when grounding is not available?

On Jun 30, 4:06 pm, John Fields <jfie...@xxxxxxxxxxxxxxxxxxxxx> 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?
.