Re: Surge Protection - Yay or Nay?

Three wires go to wall receptacles. Two (safety ground and neutral
wire) already connect a transient to earth before that receptacle. But
a third wire - the hot wire - connects transient directly to wall
receptacle. Which wire would a typically destructive type transient
approach on? Hot wire. Old and well proven technology.

A typically destructive transient has arrived at a plug-in protector
on hot wire. It is shunted - distributed - to all other wires. Will
transient then go a long distance back to AC mains panel? As Rowland
notes, earthing is essential for protection. Wire impedance - a long
wire - means that plug-in protector has no effective earthing. Too
much wire impedance. Transient will find other destructive paths
through an adjacent appliance. And so we have the classic example of a
plug-in protector even contributing to damage of the adjacent
appliance.

There is nothing obsolete about protection techniques well proven
even in 1930s research papers. Obviously plug-in power strips and
UPSes cannot shunt to earth. This paragraph provides numbers. The
concept is called impedance. For example, a 15 to 20 meter AC electric
wire might be less than 0.2 ohms resistance. But that same wire would
be maybe 120 ohms to a destructive transient. Will that wire connect a
100 amp transient to earth ground at AC mains panel? Of course not.
Even before WWII, these numbers - wire impedance - was well understood.
That 100 amp transient would leave adjacent appliance and protector at
something less than 12,000 volts. 12K volts. What kind of protection
is that? Will that 100 amp transient seek earth via the 15+ meter
wire? Of course not. The protector has provided that 100 amp
transient with other, destructive earthing paths to earth through
adjacent appliance. To earth via the telephone wire, the coax cable, a
nearby baseboard heater or even down to concrete or linoleum floor.
The paths to earth are numerous. The plug-in protector has simply
provided other undesirable paths to earth ground through transistors.

Any protection effective at the appliance is already inside that
appliance. A plug-in protector can even make undermine internal
appliance protection. Therefore plug-in protectors - that power strip
and UPS - avoid earthing discussions. They may even try to confuse by
mentioning 'ground'. Rowland assumes a wire that is too long will
somehow provide earthing. It does not. Plug-in protectors have no
effective earthing which is why they cannot provide effective
protection. As Rowland notes, earthing is essential to effective
protection.

But let's assume that long AC ground wire earths a plug-in
protector. Ground wire, bundled with other wires, only induces
transients on other wires. Now we have a building also suffering from
induced transients. Induced transients are but another reason why
plug-in protectors don't provide effective protection.

So how does Rowland challenge these facts? Insult:
Engineer? Nah - yer a marketroid.
You what? You're barking.

Meanwhile people who demonstrate this well proven technology provide
diagrams. Notice what every protection system centers on - earth
ground and short connections to that earth ground. Short connection to
earth is what plug-in protectors cannot provide and therefore avoid
mentioning:
http://www.erico.com/public/library/fep/technotes/tncr002.pdf
http://www.epri-peac.com/tutorials/sol01tut.html
http://www.telecom-protect-tech.co.uk/tp_6pp.shtml
http://www.cinergy.com/surge/ttip08.htm

The British standard is BS6651
http://www.keison.co.uk/bowthorpe/docs/Application%20Guide.pdf

How curious. These diagrams were all posted previously. Rowland even
replied that post. But somehow he still needs diagrams?

Also provided are pictures of what plug-in protectors can do. These
would be located on a rug, behind a desk, or on top of papers:
http://www.nmsu.edu/~safety/programs/gen_saf/surgeprotectorfire.htm
http://www.hanford.gov/rl/?page=556&parent=554
http://www.rbs2.com/fire.htm

Rowland, read before posting. Described were lightning damaged
26LS32 and 26LS33 drivers and receivers. Why? Adjacent power strip
protector shunted lightning into that network. Those and other damaged
ICs identified the destructive path. Adjacent protectors shunted a
lightning strike into that network - damaging those ICs. Just another
example of plug-in protectors that are not earthed and therefore
contribute to appliance damage.

Rowland McDonnell wrote:
...
You're using obsolete and confusing terminology. How about using a
circuit diagram?
...

You what? Can you translate this into plain English with a circuit
diagram?

I've never met lightning that is selective enough to only cause a spike
in a single line.
...

They do their best to shunt it to earth. Draw a circuit diagram. You
are deliberate obfuscating the issue by using woolly English to describe
a situation that needs maths and diagrams.
...

You what? You're barking.
...

You're a tosspot, mate, that's what you are. Engineer? Nah - yer a
marketroid.

What actually happens is that the transient suppressor and filter
network is designed to *SHUNT THE EXCESS POWER TO EARTH*. As a tosspot
student years ago, I demonstrated shunting to Earth protection to
protect my own circuitry against static-induced transients. And you
know what? It worked.


Okay - but given that the protection circuit shunts the transient to
earth, can you draw a circuit diagram which shows exactly how this
works?

You say you're an engineer - if you are one, you can produce a diagram
to do that in under 5 minutes. Let's see it - there are plenty of
packages for producing ASCII art that are up to the job of a simple
circuit diagram of the sort that's needed in this job.

Diagrams and maths, please, none of this deliberate obfuscation with
English.
...

Hmm. If you've had to replace the network controllers and nought else,
it sounds to me as if the transient came down the network cable, not the
mains wiring. That'd be down to poor cable routing at a guess.
...

You what? How can a protection circuit inside a power strip that is
designed to shunt transients and noise to Earth - show me the circuit
diagram and current flows which
...

.

Relevant Pages

  • Re: How to PostMortem?
    ... provide that all so essential common mode transient ... protection is about earthing - and where that earthing is ... AWG to connect to earth ground and water pipe. ... and wire to remove electricity from water pipe must be 6 AWG ...
    (comp.os.linux.setup)
  • Re: Whole house surge suppressors
    ... Ground tester is for measuring the conductivity of earth. ... created by wire too long, splices, sharp bends, wire inside metallic ... Conductivity of earth ground is only one factor in surge protection. ...
    (sci.electronics.basics)
  • Re: Weather Station and Lighting
    ... Lightning protection, as demonstrated by Franklin in 1752, ... Lightning seeks earth ground. ... A wire suspended over ...
    (uk.sci.weather)
  • Re: Ground Rod For House ?
    ... Provided was an example of wire impedance (it was not a ... earthing is good for human safety but essential to transistor ... Above is about earthing for the secondary protection ... Each layer of protection is defined by its single point earth ...
    (alt.home.repair)
  • Re: Lightning and computer?
    ... maintain current on a path to earth. ... Disconnecting works if the electronics are removed from that ... Facilities that require even better protection make ... The transient will then find other 'sneak' ...
    (microsoft.public.windowsxp.hardware)
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