westom wrote:
On Mar 22, 7:31 pm, Doug White wrote:
We've been thinking of getting one installed, so I did a little research.
Leviton seems to be the biggest vendor in the US. They have an
interesting dodge, which is a surge arrestor that goes in series with
electric meter, inside the metter housing. In my case, this is outside
of the house, which means if it turns into a fireball, it probably won't
do a lot of damage.
That Belkin did what plug-in protectors do too often. Threaten
human life. Any protector that fails during a surge was ineffective -
grossly undersized for that surge.
The only Belkin that failed in this thread was from crossed power lines.
It was not a surge, and neither service panel or plug-in suppressors are
designed to protect from the much longer duration events caused by
crossed power lines.
The Leviton and 'whole house'
protectors from so many other companies much earth a direct lightning
strike - and remain functional.
Service panel suppressors are a real good idea.
But from the NIST guide:
"Q - Will a surge protector installed at the service entrance be
sufficient for the whole house?
A - There are two answers to than question: Yes for one-link appliances
[electronic equipment], No for two-link appliances [equipment connected
to power AND phone or cable or....]. Since most homes today have some
kind of two-link appliances, the prudent answer to the question would be
NO - but that does not mean that a surge protector installed at the
service entrance is useless."
Service panel suppressors do not prevent high voltages from developing
between power and signal wires. To limit the voltage you need a *short*
wire connecting the cable/phone entrance protectors to the ground at the
power service.
(And as someone pointed out, a near lightning strike can then induce
voltages with interior house wiring acting as an antenna.)
Much of the equipment damaged has power plus phone/cable connections,
and is likely damaged by high voltage between power and signal wires.
The most rare of surges is 100,000 amps. An IEEE paper demonstrates
what happens when that 100,000 lightning strike hits the utility power
wire. Maybe 40,000 amps attempts to enter the home. (the IEEE
picture assumes the 'primary' surge protection system is also properly
installed).
Martzloff (NIST surge expert) has a paper (probably what w refers to)
that has a 100,000A lightning strike to a utility pole behind a house
with typical urban overhead distribution. The calculated average
probability of a worse event is once in 8,000 years. There are multiple
paths to earth so 'only' 40,000A is directed to the house on the service
neutral. Service neutrals in the US are connected to ground at the
service panel and connected to the earthing electrode(s) dissipating
that energy. Some of the energy is transferred to the hot wires and the
max probable surge current per wire is 10,000A (also in the IEEE guide
pdf page 27).
Incidentally, at about 6,000V from hot bus to enclosure (ground) there
is arc-over. After the arc is established the voltage is hundreds of
volts. If there is no service panel suppressor this is what dissipates
most of the energy on the hot wires. It is one of the reasons so little
energy is dissipated in MOVs in plug-in suppressors.
Companies that
sell protectors for real world protection include Leviton, Square D,
General Electric, Intermatic, Keison, and Siemens. An effective
Cutler-Hammer solution sells in Lowes and Home Depot for less than
$50.
Repeating traders response to w's repeated drivel - the "real world
protection" all these manufacturers (except SquareD) sell includes
plug-in suppressors. And the $50 devices do not meet w's minimum specs.
For its best service panel suppressor SquareD says "electronic equipment
may need additional protection by installing plug-in [suppressors] at
the point of use", and the connected equipment warranty is double when
"used in conjunction with ... a point of use surge protective device."
Bud has kindly provided the IEEE citation that shows same. See:
http://www.lightningsafety.com/nlsi_lhm/IEEE_Guide.pdf
On page 42 Figure 8 - the surge energy was permitted inside a
building. Since he was only using plug-in protectors, then the surge
found earth ground 8,000 volts destructively via the adjacent TV.
That is what protectors do.
If poor w could only read and think he could discover what the IEEE
guide says in this example:
- A plug-in suppressor protects the TV connected to it.
- "To protect TV2, a second multiport protector located at TV2 is required."
- In the example a surge comes in on a cable service with the ground
wire from cable entry ground block to the ground at the power service
that is far too long (as in my last post). In that case the IEEE guide
says "the only effective way of protecting the equipment is to use a
multiport [plug-in] protector."
- w's favored power service suppressor would provide absolutely NO
protection.
It is simply a lie that the plug-in suppressor in the IEEE example
damages the second TV.
Lacking any source that supports his drivel w tries to twist an example
in the IEEE guide that shows how plug-in suppressors provide protection.
Your concern is the rare surge that will overwhelm
internal appliance protection (ie my friend's 33,000 volt wire
dropping on local distribution).
Neither plug-in or service panel suppressors will reliably protect from
crossed power lines. This is idiocy.
Provide a spec from any manufacturer that claims such protection.
Therefore any money wasted on plug-in protectors is better
spent upgrading earth ground.
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." That is - short ground wires
from the telephone and cable entry protectors (and dish...) to the
ground at the power service.
Belkin does not even claim effective protection
in its specs.
Complete nonsense.
No earth ground means no effective protection.
A protector is only as effective as its earth ground.
w's religious mantras protects him from disturbing thoughts (aka reality).
Still not explained - why aren't airplanes crashing daily when they get
hit by lightning (or do they drag an earthing chain)?
Everyone is in favor of earthing. The IEEE guide explains, for anyone
who can think, that plug-in suppressors do not work primarily by
earthing and that earthing occurs elsewhere.
For real science read the IEEE and NIST guides - links provided . Both
say plug-in suppressors are effective.
There are 98,615,938 other web sites, including 13,843,032 by lunatics,
and w can't find another lunatic that says plug-in suppressors are
NOT effective. All you have are w's opinions based on his religious
belief in earthing.
Still never answered - simple 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"?
- Why does the NIST guide say "One effective solution is to have the
consumer install" a multiport plug-in suppressor?
- How would a service panel suppressor provide any protection in the
IEEE example, pdf page 42?
- Why does the IEEE guide say for distant service points "the only
effective way of protecting the equipment is to use a multiport
[plug-in] protector"?
- Why do your favorite manufacturers make plug-in suppressors?
- Why does favorite manufacturer SquareD say (for their service panel
suppressor) "electronic equipment may need additional protection by
installing plug-in [suppressors] at the point of use"?
--
bud--