To further that, check every single connection in your electrical system
as any part could have sustained damage. This really isn't as bad as it
might sound, it shouldn't take more than a weekend day to do unless you
have a really large house. Check each connection for signs of arcing and
damage and tighten the connection.
Since burned connections have higher resistance they generate heat under
load, furthering the damage until they fail. If you inspect and find any
problem spots now, you can prevent failures in the future and
potentially a fire.
Single point ground is only the start of protection. For example,
telephone lines already have a 'whole house' protector installed for
free. But that will only be as effective as the earth ground it
connects to. You are responsible for that ground. IOW cable TV,
telephone, satellite dish cable, and all three AC electric wires must
make a short ('less than 10 foot') connection to that same earth
Cable needs no protector. A short wire must connects the cable to
that single point ground. No protector does protection. Protector
only makes a connection from each wire to earth. Earth does the
Only one AC electric wire is earthed. You must install a 'whole
house' protector to earth the other two. If not, then you still have
Nothing (ie a millimeter gap) will protect from destructive surges.
Protection means energy is not inside the building. Either a direct
lightning strike (ie to utility wires) is harmlessly earthed without
entering the building. Or that surge will seek earth destructively
via appliances. It is that simple. Nothing inside a house will stop
or absorb a destructive surge. If permitted inside, that energy will
find numerous paths destructively via appliances.
A direct lightning strike is typically 20,000 amps. So a minimally
sized 'whole house' protector is 50,000 amps. More responsible
companies such as Intermatic, Leviton, Keison, Square D, Siemens, and
General Electric sell these. A Cutler-Hammer protector sells in Lowes
and Home Depot for less than $50. Earthed protectors are installed so
that direct lightning strikes cause no damage even to a protector.
Page 42 Figure 8 shows what happens when a surge is permitted inside
A protector must earth (and not absorb) that energy. If not located
close to earth, then the surge will earth destructively through a
nearby appliances - 8000 volts destructively through that TV.
Protectors do not provide protection. Effective protectors connect
energy harmlessly to earth - or do nothing.
The NIST citation also makes that point bluntly in:
If a protector does not have a short connection to earth, then where
do hundreds of thousands of joules dissipate? In hundreds of joules
inside a 'magic box' protector? Of course not. The NIST says:
Three AC wires enter the building. One (the neutral) should make a
short (ie 'less than 10 foot') connection to that earthing electrode.
Other two do not connect to earth IF a 'whole house' protector is
missing. If any incoming wire does not connect to earth, then surge
energy is inside the house - destructively. Your protection is always
- always - about where energy dissipates.
Same also applies to lightning rods. Also as effective as its earth
ground. If no lightning rods, then that is an incoming path for that
energy. Generally most destructive surges enter via incoming
utilities wires (overhead or underground). But if more aggressive
protection is required, then also consider lightning rods.
In every case, no magic box averts surge damage. Either a protector
or lightning rod makes a short connection to earth. Or you have
ineffective protection. The most critical component in lightning
protection (from direct strikes) is the earth electrode - the only
component always required in every protection system. So critical
that many expand that earthing. Earthing that must both meet and
exceed post 1990 National Electrical code.
Above was only the secondary protection system. Also inspect your
primary protection system. What provides the protection? A picture
of what to inspect:
I guess anyone that has a whole house surge protector installed at the
panel in the basement or garage should go take it out. You know,
those surge protectors made for exactly that type of installation by
all those companies on your list of "responsible" manufacturers.
I'm still waiting for the link to that $50 50,000 amp rated surge
protector at Lowes.
Yawn. It's widely known that MOVs degrade over time when subjected
to surges. So, in fact, while they can protect equipment, they are
in fact often damaged as a result.
The part W always leaves out is that the NIST and IEEE also show point
of use surge protectors used as part of an overall surge protection
For phone, cable, satellite... the important point is connection with a
*short* wire to the ground/earthing at the power service. With a strong
surge the building ground can lift thousands of volts above absolute"
ground. Much of the protection is that power and cable and phone and
satellite wires lift together.
Doesnt need a protector? The IEEE guide says there is no requirement
to limit the voltage developed between the core and the sheath. .... The
only voltage limit is the breakdown of the F connectors, typically ~24
kV. And "there is obviously the possibility of damage to TV tuners and
cable modems from the very high voltages that can be developed,
especially from nearby lightning." (A plug-in suppressor will limit the
voltage from core to shield.)
(Links to the IEEE and NIST surge protection guides was in my first post.)
w has a religious belief (immune from challenge) that surge protection
must directly use earthing. Thus in his view plug-in suppressors (which
are not well earthed) can not possibly work. The IEEE guide explains
plug-in suppressors work by CLAMPING (limiting) the voltage on all wires
(signal and power) to the common ground at the suppressor. Plug-in
suppressors do not work primarily by earthing (or stopping or
absorbing). The guide explains earthing occurs elsewhere. (Read the
guide starting pdf page 40).
If using plug-in suppressors note that all interconnected equipment
needs to be connected to the same suppressor. External connections, like
phone, also need to go through the suppressor. Connecting all wiring
through the suppressor prevents damaging voltages between power and
Service panel suppressors are a 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."
The NIST guide suggests the major cause of equipment damage is high
voltage between power and phone/cable wires. Service panel suppressors
do not prevent that high voltage. To limit the voltage you need a
*short* wire connecting the cable/phone entrance protectors to the
ground at the power service.
As explained in my other post there is essentially zero probability of a
surge on power wires higher than 10,000A. But a 50,000A rating means
the suppressor will have a long life.
All these "responsible companies" except SquareD make plug-in
suppressors. SquareD says for their "best" service panel suppressor
"electronic equipment may need additional protection by installing
plug-in [suppressors] at the point of use."
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. In that case the IEEE guide says "the only
effective way of protecting the equipment is to use a multiport
- w_'s favored power service suppressor would provide absolutely NO
The whole point of the example is that plug-in suppressors are effective.
Of course not.
I explained in my first post where the energy goes. If poor w could
only read and think...
What does the NIST guide really say about plug-in suppressors?
They are "the easiest solution".
And "one effective solution is to have the consumer install" a multiport
Plug-in suppressors are "magic" to w because his religious blinders do
not let him see how they work - clearly explained in the IEEE guide.
Flying planes are crashing every day because they are hit by lightning
ad have no "earthing electrode".
Never seen - a link to a reputable source that agrees with w that
plug-in suppressors are not effective.
Never seen - answers to simple questions:
- Why do the only 2 examples of protection in the IEEE guide use plug-in
- Why does the NIST guide says plug-in suppressors are "the easiest
- 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
- Why do your "responsible manufacturers" make plug-in suppressors?
- Why does "responsible" manufacturer SquareD says "electronic
equipment may need additional protection by installing plug-in
[suppressors] at the point of use"?
For real science read the IEEE and NIST guides. Both say plug-in
suppressors are effective.
On Fri, 4 Jun 2010 17:40:47 -0400, "John Grabowski"
Agreed, and If this was my house, I'd pull out every outlet, switch
and light fixture and check for burnt stuff. The ends of wirenuts
will blow right off, wires are bends will literally burn away
sections. I know this because a neighbor got hit, and it took out all
of his barn wiring and a section of the house. In the house, there
were several wires burned, one hot lead was shorted to the ground wire
inside the box. That breaker was ruined. In the barn, there was a
main feed wire that blew a hole thru the insulation right where the
wires bent at the breaker, the hot lead was welded right to the metal
box, and thus tripped the main breaker feeding that barn (located in
another building). In that building, there was a section of wire in
the main panel that was so burnt that it caused a sort of resistor (a
charred section of molten copper and carbon). The lights in there
flickered. All of this had to be fixed.
After the power was restored to the barn, which controls his well
water pump, the water was turned on, and we found a water leak in the
basement of the house. Right in the end of a copper elbow, there was
a pinhole, with water shooting out. Looked like the lightning just
exited out that elbow rather than making the turn to follow the pipe.
The pinhole was a noticable burn, not just a hole caused by corrosion.
In another situation, where I lived about 28 years ago, a friend of
mine had his telephone explode. One of the old wall phones. It took
out a whole section of sheetrock and left nothing but chunks of
plaster and phone pieces all over the floor. The phone company had to
rewire everything from the phone, throughout the whole interior of the
house, outside the entire underground wire to the box along the road
(whatever they call those connection box things), and even some of the
wire feeding that connection box. The telco guys told him that the
wires were nothing but plastic with no copper left in them. I saw a
section, just melted plastic insulation. He was lucky there was no
fire caused by that.
Anyhow, once you're hit by lightning, you really need to take apart
all wiring and check it. Look closely in your breaker panel for
charred stuff, and definately check grounding wires, clamps, etc.
I had a big strike costing the insurance co about 20,000 in electrical
stuff, You really need to test everything even the boiler, its very
possible things will go bad within a year that look fine now. If it
burnt up things wireing can also be affected, my lightning loosened
the wires on many sockets, loosened bulbs in sockets. It did damage
from the 3rd floor to the basement, all 4 floors, so take your time
and check everything, even amp draw on the frige, AC, pumps, etc. Did
you have surge protectors, you can sldo get a cheap lightning arrestor
for your mains. I hope the damage is minimal.
All overhead. Just down the street from me they do have underground wires
and a different feed from the substation. We get a short power outage maybe
once or twice a year, usually a few minutes to an hour. They fare only
slightly better than us as the lines to that group of houses is all overhead
It is a good time to take a test inventory of everything in the house
that is electrical or might have a processor. We experienced a
strike near the house last September and knew we had damage
immediately. Computer was dead. Garage door openers were dead, Older
TV dead. Our insurance agent told us to take our time doing a damage
assessment because there is likely to be more. She was right. Over
a period of two weeks we found out all of the local wireless providers
network (antenna, modem, etc) was damaged - just took a few days to
die. We found 6 GFIs that were damaged, all surge protectors in the
house were dead. In addition to garage door opener circuit boards,
one of the light sensors croaked within a week, etc, etc, etc. What
looked like a $1,200 claim a couple of days after the strike ended up
being more than $2,000.
We were up at 2:00am when it hit. It struck somewhere just north of
the house but I never found the attach point. All north windows went
pure white, as did the interior of the house and the noise sounded
like an M-80 in a trash can, inside of the house! Noise and flash
exactly concurrent. Scary by itself but we saw sparks flying out of a
kitchen GFI and that lasted 2-3 seconds.
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