Last week we had an unfortunate incident in the neighborhood - a very large
bay laurel tree with root fungus snapped and took down the power lines
about 5 houses down. In the house, I witnessed the lights flickering on
and off, but also getting VERY bright for upwards of ten seconds.

Finally the power went out until PG&E restored it about 15 hours later.

Casualties of this event include (so far determined, more may be hiding):
- Fan on my fridge that cools the heat exchanger coils.
- Several fluorescent lights
- VCR in the entertainment console
- Switching battery charger for my NEW Craftsman cordless drill/flashlight
kit
- A Leviton X-10 light switch/dimmer that was STUCK ON, melting, and might
have caught the house on fire had my wife not noticed it was getting warm
(after the power came back on).
- Two Belkin power strips with surge supression, which so far as I can
tell, protected everything downstream. One of these things REALLY melted
and blew a hole out the back, leaving a large scorch/toxic waste residue on
my wall. In their failure mode these things remained shorted out, tripping
the breakers.

Fortunately none of my computers were affected (they're on an APC UPS which
appears to still be OK). I'm still going through my audio rack to see if
anything got toasted (something is shorted downstream of my Furman PL-8 but
the Furman seems OK - think I would have been happier if it had sacrificed
itself but I don't know that it claimed to be a surge suppressor).

I HIGHLY recommend these gadgets for any electronic equipment you deem
valuable. 10 bucks to replace one of these is a great investment. The
destroyed stuff (none of which was one a surge suppressor) is probably
going to cost me about $300 to replace. Not the end of the world but would
have been nice to avoid.

"Digital Larry" wrote in message
9.11
Last week we had an unfortunate incident in the neighborhood - a very
large bay laurel tree with root fungus snapped and took down the
power lines about 5 houses down. In the house, I witnessed the
lights flickering on and off, but also getting VERY bright for
upwards of ten seconds.

If you're serious about controlling external surges, you'll get an
electrician to install a whole-house surge suppressor. Recommended for
people who live in places with lots of near lightening hits, or a power
company that doesn't maintain its lines very well.

"Digital Larry" wrote in message
9.11
Last week we had an unfortunate incident in the neighborhood - a very
large bay laurel tree with root fungus snapped and took down the
power lines about 5 houses down. In the house, I witnessed the
lights flickering on and off, but also getting VERY bright for
upwards of ten seconds.

If you're serious about controlling external surges, you'll get an
electrician to install a whole-house surge suppressor. Recommended for
people who live in places with lots of near lightening hits, or a power
company that doesn't maintain its lines very well.

On Mon, 06 Sep 2004 21:14:42 GMT, Digital Larry
wrote:

Casualties of this event include (so far determined, more may be hiding):
- Fan on my fridge that cools the heat exchanger coils. . .

I HIGHLY recommend these gadgets for any electronic equipment you deem
valuable. 10 bucks to replace one of these is a great investment. The
destroyed stuff (none of which was one a surge suppressor) is probably
going to cost me about $300 to replace. Not the end of the world but would
have been nice to avoid.

Damn. Now I gotta buy one for the refrigerator. Better get one also
for my rechargable Love Doll.


Willie K. Yee, M.D. http://users.bestweb.net/~wkyee
Developer of Problem Knowledge Couplers for Psychiatry http://www.pkc.com
Webmaster and Guitarist for the Big Blue Big Band http://www.bigbluebigband.org

On Mon, 06 Sep 2004 21:14:42 GMT, Digital Larry
wrote:

Casualties of this event include (so far determined, more may be hiding):
- Fan on my fridge that cools the heat exchanger coils. . .

I HIGHLY recommend these gadgets for any electronic equipment you deem
valuable. 10 bucks to replace one of these is a great investment. The
destroyed stuff (none of which was one a surge suppressor) is probably
going to cost me about $300 to replace. Not the end of the world but would
have been nice to avoid.

Damn. Now I gotta buy one for the refrigerator. Better get one also
for my rechargable Love Doll.


Willie K. Yee, M.D. http://users.bestweb.net/~wkyee
Developer of Problem Knowledge Couplers for Psychiatry http://www.pkc.com
Webmaster and Guitarist for the Big Blue Big Band http://www.bigbluebigband.org

"Digital Larry"

Last week we had an unfortunate incident in the neighborhood - a very
large
bay laurel tree with root fungus snapped and took down the power lines
about 5 houses down. In the house, I witnessed the lights flickering on
and off, but also getting VERY bright for upwards of ten seconds.


** No cheap MOV is capable of protecting your electrical/electronic gear
from an event like the above where the AC voltage goes high. They are good
only for spike voltage protection ( ie brief lightning induced pulses) -
at best.

The problem is that MOVs do not hard clamp the AC voltage until the level
is about DOUBLE the normal maximum.

If you want to protect against rises in the AC voltage then use a large (
ie 2000 VA) toroidal 1:1 transformer to feed vulnerable items like
electronics. Such a transformer can be made to magnetically saturate very
sharply and blow the supply side fuse if there AC voltage rises more than
about 15 - 20 %.




........... Phil

"Digital Larry"

Last week we had an unfortunate incident in the neighborhood - a very
large
bay laurel tree with root fungus snapped and took down the power lines
about 5 houses down. In the house, I witnessed the lights flickering on
and off, but also getting VERY bright for upwards of ten seconds.


** No cheap MOV is capable of protecting your electrical/electronic gear
from an event like the above where the AC voltage goes high. They are good
only for spike voltage protection ( ie brief lightning induced pulses) -
at best.

The problem is that MOVs do not hard clamp the AC voltage until the level
is about DOUBLE the normal maximum.

If you want to protect against rises in the AC voltage then use a large (
ie 2000 VA) toroidal 1:1 transformer to feed vulnerable items like
electronics. Such a transformer can be made to magnetically saturate very
sharply and blow the supply side fuse if there AC voltage rises more than
about 15 - 20 %.




........... Phil

"Arny Krueger" wrote in message
...
"Digital Larry" wrote in message
9.11
Last week we had an unfortunate incident in the neighborhood - a very
large bay laurel tree with root fungus snapped and took down the
power lines about 5 houses down. In the house, I witnessed the
lights flickering on and off, but also getting VERY bright for
upwards of ten seconds.

HV cables falling on lower Voltage cables usually toast things like
Lightbulbs fairly quickly so it sounds suspiciously like a Neutral Failure -
or a variation on that Theme.

If you're serious about controlling external surges, you'll get an
electrician to install a whole-house surge suppressor. Recommended for
people who live in places with lots of near lightening hits, or a power
company that doesn't maintain its lines very well.

So how would it have been of assistance in this case ? ie raised AC Mains ?
MOV based whole house protection would have become hot and the Thermal fuse
would have opened taking the 'whole house protection out of the Picture
completely probably within the first few Seconds.

Larrys Surge Supressors in this case worked by tripping the Breakers - Not
by effectively clamping the AC mains. As it is if I was Larry I would have
to seriously reconsider the Belkin brand Surge arrestors as it sounds like
one of them came dangerously close to causing a Fire.
As for Lightning for a Surge arrestor to be anywhere near effective it needs
to reduce and Differential voltage across the Device and Surge protection
built into equipment typically offers Protection as good as any 'whole house
protection'. Fortunately though Lightning damage from medium to distant
Strikes is very rare via AC mains (Lightning damage via Phone/Data Lines is
far far more common) and in the event of a near or Direct strike almost no
amount of Practical Lightning protection will suffice - TV Transmitters have
typically the best Lightning Protection available and even they frequently
suffer Lightning damage.
The most Effective Surge or Lightning Protection is simply a nice hefty 1:1
Isolation Transformer - A Torodial works best as Phil suggests - with a
Primary Fuse or Breaker and keep any Phone lines entering this protected
zone disconnected if there is any threat of a Storm.

Regards
Richard Freeman

"Arny Krueger" wrote in message
...
"Digital Larry" wrote in message
9.11
Last week we had an unfortunate incident in the neighborhood - a very
large bay laurel tree with root fungus snapped and took down the
power lines about 5 houses down. In the house, I witnessed the
lights flickering on and off, but also getting VERY bright for
upwards of ten seconds.

HV cables falling on lower Voltage cables usually toast things like
Lightbulbs fairly quickly so it sounds suspiciously like a Neutral Failure -
or a variation on that Theme.

If you're serious about controlling external surges, you'll get an
electrician to install a whole-house surge suppressor. Recommended for
people who live in places with lots of near lightening hits, or a power
company that doesn't maintain its lines very well.

So how would it have been of assistance in this case ? ie raised AC Mains ?
MOV based whole house protection would have become hot and the Thermal fuse
would have opened taking the 'whole house protection out of the Picture
completely probably within the first few Seconds.

Larrys Surge Supressors in this case worked by tripping the Breakers - Not
by effectively clamping the AC mains. As it is if I was Larry I would have
to seriously reconsider the Belkin brand Surge arrestors as it sounds like
one of them came dangerously close to causing a Fire.
As for Lightning for a Surge arrestor to be anywhere near effective it needs
to reduce and Differential voltage across the Device and Surge protection
built into equipment typically offers Protection as good as any 'whole house
protection'. Fortunately though Lightning damage from medium to distant
Strikes is very rare via AC mains (Lightning damage via Phone/Data Lines is
far far more common) and in the event of a near or Direct strike almost no
amount of Practical Lightning protection will suffice - TV Transmitters have
typically the best Lightning Protection available and even they frequently
suffer Lightning damage.
The most Effective Surge or Lightning Protection is simply a nice hefty 1:1
Isolation Transformer - A Torodial works best as Phil suggests - with a
Primary Fuse or Breaker and keep any Phone lines entering this protected
zone disconnected if there is any threat of a Storm.

Regards
Richard Freeman

"Richard Freeman" wrote in message

"Arny Krueger" wrote in message
...
"Digital Larry" wrote in message
9.11
Last week we had an unfortunate incident in the neighborhood - a
very large bay laurel tree with root fungus snapped and took down
the power lines about 5 houses down. In the house, I witnessed the
lights flickering on and off, but also getting VERY bright for
upwards of ten seconds.

HV cables falling on lower Voltage cables usually toast things like
Lightbulbs fairly quickly so it sounds suspiciously like a Neutral
Failure - or a variation on that Theme.

If you're serious about controlling external surges, you'll get an
electrician to install a whole-house surge suppressor. Recommended
for people who live in places with lots of near lightening hits, or
a power company that doesn't maintain its lines very well.

So how would it have been of assistance in this case ? ie raised AC
Mains ? MOV based whole house protection would have become hot and
the Thermal fuse would have opened taking the 'whole house protection
out of the Picture completely probably within the first few Seconds.

The whole-house protection MOV is downstream of the main house fuses or
circuit breakers, per code. The MOVs go into a low impedance state (i.e.,
crowbar like) due to the overvoltage, blow the main fuses or trip the main
breakers, and everything in the house is protected.

Larry's Surge Supressors in this case worked by tripping the Breakers
- Not by effectively clamping the AC mains.

Right. The whole-house approach just moves the action up stream.

As it is if I was Larry I
would have to seriously reconsider the Belkin brand Surge arrestors
as it sounds like one of them came dangerously close to causing a
Fire.

My point is that small protectors in the house are like trying to protect
your whole body with many tiny band-aids.


As for Lightning for a Surge arrestor to be anywhere near
effective it needs to reduce and Differential voltage across the
Device and Surge protection built into equipment typically offers
Protection as good as any 'whole house protection'.


Plan A - shun lightening to ground within a foot or two of the equipment,
via a small piece of grounding wire plugged into an outlet.

Play B - shunt lightening to ground many feet from the equipment, via a big
hunking chunk of copper permanently connected to the safety ground point for
the whole house.

It's up to you. ;-)

Fortunately
though Lightning damage from medium to distant Strikes is very rare
via AC mains (Lightning damage via Phone/Data Lines is far far more
common)

I've definately seen major trashing of residences via lightening that
unambigiously came in via the power lines. I've also seen trivial effects
like arcing behind the plastic plates of AC outlets due to nearby lightening
strikes.

And in the event of a near or Direct strike almost no amount
of Practical Lightning protection will suffice - TV Transmitters have
typically the best Lightning Protection available and even they
frequently suffer Lightning damage.

They get direct strikes, by the bucketload. Something about that 1000 foot
plus tower. Not the same as what I was addressing.

The most Effective Surge or
Lightning Protection is simply a nice hefty 1:1 Isolation Transformer
- A Torodial works best as Phil suggests - with a Primary Fuse or
Breaker and keep any Phone lines entering this protected zone
disconnected if there is any threat of a Storm.

If you want to fight whole house surge protecting, be my guest. After all
its your house at stake, not my house or the houses of my friends.

For the record, I live in an urban area. I have seen neighbor's houses
seriously damaged by lightening strikes to trees, which are the tallest
entities in my neighborhood. The house power system was affected in all
cases.

In this situation, a whole house protector would work a little differently.
It would keep the strike from propagating out from the circuit box. In this
mode, the protector would force tripping of the circuit breaker for the the
branch circuit that was struck by lightening. Items on that circuit would
still probably get fried, but the rest of the house would still be
protected.

"Richard Freeman" wrote in message

"Arny Krueger" wrote in message
...
"Digital Larry" wrote in message
9.11
Last week we had an unfortunate incident in the neighborhood - a
very large bay laurel tree with root fungus snapped and took down
the power lines about 5 houses down. In the house, I witnessed the
lights flickering on and off, but also getting VERY bright for
upwards of ten seconds.

HV cables falling on lower Voltage cables usually toast things like
Lightbulbs fairly quickly so it sounds suspiciously like a Neutral
Failure - or a variation on that Theme.

If you're serious about controlling external surges, you'll get an
electrician to install a whole-house surge suppressor. Recommended
for people who live in places with lots of near lightening hits, or
a power company that doesn't maintain its lines very well.

So how would it have been of assistance in this case ? ie raised AC
Mains ? MOV based whole house protection would have become hot and
the Thermal fuse would have opened taking the 'whole house protection
out of the Picture completely probably within the first few Seconds.

The whole-house protection MOV is downstream of the main house fuses or
circuit breakers, per code. The MOVs go into a low impedance state (i.e.,
crowbar like) due to the overvoltage, blow the main fuses or trip the main
breakers, and everything in the house is protected.

Larry's Surge Supressors in this case worked by tripping the Breakers
- Not by effectively clamping the AC mains.

Right. The whole-house approach just moves the action up stream.

As it is if I was Larry I
would have to seriously reconsider the Belkin brand Surge arrestors
as it sounds like one of them came dangerously close to causing a
Fire.

My point is that small protectors in the house are like trying to protect
your whole body with many tiny band-aids.


As for Lightning for a Surge arrestor to be anywhere near
effective it needs to reduce and Differential voltage across the
Device and Surge protection built into equipment typically offers
Protection as good as any 'whole house protection'.


Plan A - shun lightening to ground within a foot or two of the equipment,
via a small piece of grounding wire plugged into an outlet.

Play B - shunt lightening to ground many feet from the equipment, via a big
hunking chunk of copper permanently connected to the safety ground point for
the whole house.

It's up to you. ;-)

Fortunately
though Lightning damage from medium to distant Strikes is very rare
via AC mains (Lightning damage via Phone/Data Lines is far far more
common)

I've definately seen major trashing of residences via lightening that
unambigiously came in via the power lines. I've also seen trivial effects
like arcing behind the plastic plates of AC outlets due to nearby lightening
strikes.

And in the event of a near or Direct strike almost no amount
of Practical Lightning protection will suffice - TV Transmitters have
typically the best Lightning Protection available and even they
frequently suffer Lightning damage.

They get direct strikes, by the bucketload. Something about that 1000 foot
plus tower. Not the same as what I was addressing.

The most Effective Surge or
Lightning Protection is simply a nice hefty 1:1 Isolation Transformer
- A Torodial works best as Phil suggests - with a Primary Fuse or
Breaker and keep any Phone lines entering this protected zone
disconnected if there is any threat of a Storm.

If you want to fight whole house surge protecting, be my guest. After all
its your house at stake, not my house or the houses of my friends.

For the record, I live in an urban area. I have seen neighbor's houses
seriously damaged by lightening strikes to trees, which are the tallest
entities in my neighborhood. The house power system was affected in all
cases.

In this situation, a whole house protector would work a little differently.
It would keep the strike from propagating out from the circuit box. In this
mode, the protector would force tripping of the circuit breaker for the the
branch circuit that was struck by lightening. Items on that circuit would
still probably get fried, but the rest of the house would still be
protected.

"Arny Krueger" wrote in message ...
"Digital Larry" wrote in message
9.11
Last week we had an unfortunate incident in the neighborhood - a very
large bay laurel tree with root fungus snapped and took down the
power lines about 5 houses down. In the house, I witnessed the
lights flickering on and off, but also getting VERY bright for
upwards of ten seconds.

If you're serious about controlling external surges, you'll get an
electrician to install a whole-house surge suppressor. Recommended for
people who live in places with lots of near lightening hits, or a power
company that doesn't maintain its lines very well.

I've sold suge suppressors for years...and the best solution is a big
one on your main panel and smaller plug-in thype units at the
equipment...especially things with microprocessors..like Larry's VCR.
I'll tell you what most folks miss though are the other Cables coming
into the house...phones, television coax..etc. Any wire coming in
from the outside can bring surges to your stuff. There are 5-10
dollar units to install where those lines come into your house that
are really good to get too. YOu don't need one on every bit of
equipment.

Tom

"Arny Krueger" wrote in message ...
"Digital Larry" wrote in message
9.11
Last week we had an unfortunate incident in the neighborhood - a very
large bay laurel tree with root fungus snapped and took down the
power lines about 5 houses down. In the house, I witnessed the
lights flickering on and off, but also getting VERY bright for
upwards of ten seconds.

If you're serious about controlling external surges, you'll get an
electrician to install a whole-house surge suppressor. Recommended for
people who live in places with lots of near lightening hits, or a power
company that doesn't maintain its lines very well.

I've sold suge suppressors for years...and the best solution is a big
one on your main panel and smaller plug-in thype units at the
equipment...especially things with microprocessors..like Larry's VCR.
I'll tell you what most folks miss though are the other Cables coming
into the house...phones, television coax..etc. Any wire coming in
from the outside can bring surges to your stuff. There are 5-10
dollar units to install where those lines come into your house that
are really good to get too. YOu don't need one on every bit of
equipment.

Tom

"Richard Freeman" wrote in
:

Larrys Surge Supressors in this case worked by tripping the Breakers -
Not by effectively clamping the AC mains. As it is if I was Larry I
would have to seriously reconsider the Belkin brand Surge arrestors as
it sounds like one of them came dangerously close to causing a Fire.

Well there might be an additional explanation.

#1 Before I figured out what happened I did reset one of the breakers which
immediately popped again.

#2 Once THAT happened, I sorta realized that something was still fried so I
went and unplugged everything from the wall. After the power came back on
I went around and plugged things in one at a time. It was only when the
power strip with nothing plugged into IT blew the breaker that the cough
light went on in my knuckle-head. So this particular had been subjected to
the original event plus two more direct-short pops.

#3 An identical strip on another circuit also shorted out but it had no
visible external damage. This other one did not undergo the additional
experiments.

I'm not trying to say that a $10 power strip with suppressor is ideal. In
my case it was better than nothing, but everything that did fry, in
addition to your comments here makes me think something more robust might
be in order. In 15 years this is the first time this has happened to me,
but it's the second time in as many months that a tree has come down on the
lines and I also has a huge bay tree (3 feet diameter at base) with root
fungus fall earlier this year. This area is heavily forested.

"Richard Freeman" wrote in
:

Larrys Surge Supressors in this case worked by tripping the Breakers -
Not by effectively clamping the AC mains. As it is if I was Larry I
would have to seriously reconsider the Belkin brand Surge arrestors as
it sounds like one of them came dangerously close to causing a Fire.

Well there might be an additional explanation.

#1 Before I figured out what happened I did reset one of the breakers which
immediately popped again.

#2 Once THAT happened, I sorta realized that something was still fried so I
went and unplugged everything from the wall. After the power came back on
I went around and plugged things in one at a time. It was only when the
power strip with nothing plugged into IT blew the breaker that the cough
light went on in my knuckle-head. So this particular had been subjected to
the original event plus two more direct-short pops.

#3 An identical strip on another circuit also shorted out but it had no
visible external damage. This other one did not undergo the additional
experiments.

I'm not trying to say that a $10 power strip with suppressor is ideal. In
my case it was better than nothing, but everything that did fry, in
addition to your comments here makes me think something more robust might
be in order. In 15 years this is the first time this has happened to me,
but it's the second time in as many months that a tree has come down on the
lines and I also has a huge bay tree (3 feet diameter at base) with root
fungus fall earlier this year. This area is heavily forested.

Digital Larry wrote in message . 49.11...


I'm still going through my audio rack to see if
anything got toasted (something is shorted downstream of my Furman PL-8 but
the Furman seems OK - think I would have been happier if it had sacrificed
itself but I don't know that it claimed to be a surge suppressor).



FWIW a Furman PL-8 does indeed claim to be a surge suppressor. (Well,
I mean the manufacturer claims that it is; the PL-8 itself doesn't
claim to be anything...especially after taking a hit such as you
describe.)

Anyone seen the new "Series II" Furmans? After all the abuse they got
from SurgeX & other companies touting the advantages of series-mode
surge protection over the shunt-mode protection the PL-8 employs,
Furman came out with their own series-mode version. Same price as the
original.

Especially telling is that Furman continues to offer the shunt-mode
version as well! So they can have their cake and...

Digital Larry wrote in message . 49.11...


I'm still going through my audio rack to see if
anything got toasted (something is shorted downstream of my Furman PL-8 but
the Furman seems OK - think I would have been happier if it had sacrificed
itself but I don't know that it claimed to be a surge suppressor).



FWIW a Furman PL-8 does indeed claim to be a surge suppressor. (Well,
I mean the manufacturer claims that it is; the PL-8 itself doesn't
claim to be anything...especially after taking a hit such as you
describe.)

Anyone seen the new "Series II" Furmans? After all the abuse they got
from SurgeX & other companies touting the advantages of series-mode
surge protection over the shunt-mode protection the PL-8 employs,
Furman came out with their own series-mode version. Same price as the
original.

Especially telling is that Furman continues to offer the shunt-mode
version as well! So they can have their cake and...

"Arny Krueger" wrote in message
...
"Richard Freeman" wrote in message

"Arny Krueger" wrote in message
...
"Digital Larry" wrote in message
9.11
Last week we had an unfortunate incident in the neighborhood - a
very large bay laurel tree with root fungus snapped and took down
the power lines about 5 houses down. In the house, I witnessed the
lights flickering on and off, but also getting VERY bright for
upwards of ten seconds.

HV cables falling on lower Voltage cables usually toast things like
Lightbulbs fairly quickly so it sounds suspiciously like a Neutral
Failure - or a variation on that Theme.

If you're serious about controlling external surges, you'll get an
electrician to install a whole-house surge suppressor. Recommended
for people who live in places with lots of near lightening hits, or
a power company that doesn't maintain its lines very well.

So how would it have been of assistance in this case ? ie raised AC
Mains ? MOV based whole house protection would have become hot and
the Thermal fuse would have opened taking the 'whole house protection
out of the Picture completely probably within the first few Seconds.

The whole-house protection MOV is downstream of the main house fuses or
circuit breakers, per code. The MOVs go into a low impedance state (i.e.,
crowbar like) due to the overvoltage, blow the main fuses or trip the main
breakers, and everything in the house is protected.

Well that would work if a MOV could reliably trip a breaker however as a
Crowbar particularly for (relatively) minor over voltages the MOV often does
not draw enough current to reliably trip a Breaker or Blow a 100+Amp service
fuse.
Although MOVs do often go Short Circuit and trip Breakers as they did for
Larry they also at least as often (if not more often) conduct enough Current
to get Bloody hot and set fire to the Fusebox/Power strip/House which is why
all MOV based surge arrestors in Australia are required to have a Thermal
fuse to disconnect the MOV in this event.

Larry's Surge Supressors in this case worked by tripping the Breakers
- Not by effectively clamping the AC mains.

Right. The whole-house approach just moves the action up stream.

As it is if I was Larry I
would have to seriously reconsider the Belkin brand Surge arrestors
as it sounds like one of them came dangerously close to causing a
Fire.

My point is that small protectors in the house are like trying to protect
your whole body with many tiny band-aids.

While I will not disagree that cheap and Nasty plug in protection is pretty
useless you could say the same for cheap 'whole house' protectors as well
It also depends which protection rationale you are trying to Follow.
MOV based protectors are designed to (as you said) shunt enough current to
earth to limit the Voltage rise to manageable limits - where 'Whole house
protection' fails is in Near or Direct strikes (well actually most Lightning
protection regimes are prone to Failures in Direct strikes - just ask any
Telco or Transmitter operator) the other and common Protection Rationale is
to ensure that all incoming and Outgoing wires/connectors are at rouglhy the
same potential.
Most serious Surge protection employs aspects of both however given the High
currents etc involved in Lightning strikes it is actually a very hard call
to shunt enough current to earth in most domestic installations to be
effective - as even Earth itself suffers a Rise in the order of 100,000
Volts in the event of a Lightning strike.

As for Lightning for a Surge arrestor to be anywhere near
effective it needs to reduce and Differential voltage across the
Device and Surge protection built into equipment typically offers
Protection as good as any 'whole house protection'.


Plan A - shun lightening to ground within a foot or two of the equipment,
via a small piece of grounding wire plugged into an outlet.

Not quite -
Plan A shunt lightning around your Electronic equipment by ensuring that any
Potential rise across the device is kept as low as possible close to the
equipment and essentially let your equipment ride out the Strike.

Play B - shunt lightening to ground many feet from the equipment, via a
big
hunking chunk of copper permanently connected to the safety ground point
for
the whole house.

Plan B shunt Lightning to a Ground which will rise to over 100KV above
nominal Earth and then create paths from this Single Earth point to lower
potential points around the House via the house wiring this in fact offers
little if any better protection than MEN mains already has.

It's up to you. ;-)

it is indeed and both Strategies run into serious problems as soon as you
introduce more external wiring - especially if (as is the case with phone
lines) that wiring is not very well Earthed and that really is the advantage
of local adequate surge arrestors - nb for this to have any hope of
providing any protection it needs to be a decent surge supressor and pretty
well nothing beats a hunk of iron with copper wrapped around it.


Fortunately
though Lightning damage from medium to distant Strikes is very rare
via AC mains (Lightning damage via Phone/Data Lines is far far more
common)

I've definately seen major trashing of residences via lightening that
unambigiously came in via the power lines. I've also seen trivial effects
like arcing behind the plastic plates of AC outlets due to nearby
lightening
strikes.

however for each event like this there are hundreds of cases of Lightning
coming in via a Phone or data line.

And in the event of a near or Direct strike almost no amount
of Practical Lightning protection will suffice - TV Transmitters have
typically the best Lightning Protection available and even they
frequently suffer Lightning damage.

They get direct strikes, by the bucketload. Something about that 1000 foot
plus tower. Not the same as what I was addressing.

Well yes and no the basic Idea is still the same - with these beasties the
trick is still to ensure that all the equipment remains at the same
potential (or as close to it as possible) and rides out the strike - hence
the room is typically a metal box with a single tie to a very comprehensive
earth system - often covering 1/2 an Acre or more

The most Effective Surge or
Lightning Protection is simply a nice hefty 1:1 Isolation Transformer
- A Torodial works best as Phil suggests - with a Primary Fuse or
Breaker and keep any Phone lines entering this protected zone
disconnected if there is any threat of a Storm.

If you want to fight whole house surge protecting, be my guest. After all
its your house at stake, not my house or the houses of my friends.

whole house Protection is inexpensive.

For the record, I live in an urban area. I have seen neighbor's houses
seriously damaged by lightening strikes to trees, which are the tallest
entities in my neighborhood. The house power system was affected in all
cases.

Near and or Direct strikes affect everything pretty well.

In this situation, a whole house protector would work a little
differently.
It would keep the strike from propagating out from the circuit box. In
this
mode, the protector would force tripping of the circuit breaker for the
the
branch circuit that was struck by lightening. Items on that circuit would
still probably get fried, but the rest of the house would still be
protected.

I disagree - first the Whole house protector is not going to trip the rather
leisurely breakers for probably 20 odd mS the strikes will be over in - lets
say 6 x 100uS strikes - 7-800uS. Secondly the whole House protector if it
does go hard short for the strike (MOVs don't of course but that is another
story) will then direct say 1/10th of a typical 100,000 odd Amp strike to an
Earth stake where less than 10 Ohms is considered good. well Ohms law is not
difficult to apply and this gives us an EPR (GPR for the Americans) of
100,000 Volts this of course is enough Potential Difference to cause current
flow through the Building wiring to other attractive earth points around the
House. In short Widespread damage.

OTOH for Localised surge supression you are merely trying to keep the
Potential Difference across your equipment to a minimum and by keeping your
Protection local you are essentially letting all your equipment ride out the
Strike.

The real problem with most Plug in surge supression is that it is usually
made down to a Price rather than up to a standard and people buy cheap and
crappy surge arrestors and are then surprised when they fail to provide any
protection at all. Also remember that with the Very high currents and Energy
levels involved there is pretty well no such thing as Complete 100%
effective Surge/Lightning Protection and these Devices are really best being
considered as a last line of Defence for when you cannot or forget to unplug
equipment during a Thunderstorm.

"Arny Krueger" wrote in message
...
"Richard Freeman" wrote in message

"Arny Krueger" wrote in message
...
"Digital Larry" wrote in message
9.11
Last week we had an unfortunate incident in the neighborhood - a
very large bay laurel tree with root fungus snapped and took down
the power lines about 5 houses down. In the house, I witnessed the
lights flickering on and off, but also getting VERY bright for
upwards of ten seconds.

HV cables falling on lower Voltage cables usually toast things like
Lightbulbs fairly quickly so it sounds suspiciously like a Neutral
Failure - or a variation on that Theme.

If you're serious about controlling external surges, you'll get an
electrician to install a whole-house surge suppressor. Recommended
for people who live in places with lots of near lightening hits, or
a power company that doesn't maintain its lines very well.

So how would it have been of assistance in this case ? ie raised AC
Mains ? MOV based whole house protection would have become hot and
the Thermal fuse would have opened taking the 'whole house protection
out of the Picture completely probably within the first few Seconds.

The whole-house protection MOV is downstream of the main house fuses or
circuit breakers, per code. The MOVs go into a low impedance state (i.e.,
crowbar like) due to the overvoltage, blow the main fuses or trip the main
breakers, and everything in the house is protected.

Well that would work if a MOV could reliably trip a breaker however as a
Crowbar particularly for (relatively) minor over voltages the MOV often does
not draw enough current to reliably trip a Breaker or Blow a 100+Amp service
fuse.
Although MOVs do often go Short Circuit and trip Breakers as they did for
Larry they also at least as often (if not more often) conduct enough Current
to get Bloody hot and set fire to the Fusebox/Power strip/House which is why
all MOV based surge arrestors in Australia are required to have a Thermal
fuse to disconnect the MOV in this event.

Larry's Surge Supressors in this case worked by tripping the Breakers
- Not by effectively clamping the AC mains.

Right. The whole-house approach just moves the action up stream.

As it is if I was Larry I
would have to seriously reconsider the Belkin brand Surge arrestors
as it sounds like one of them came dangerously close to causing a
Fire.

My point is that small protectors in the house are like trying to protect
your whole body with many tiny band-aids.

While I will not disagree that cheap and Nasty plug in protection is pretty
useless you could say the same for cheap 'whole house' protectors as well
It also depends which protection rationale you are trying to Follow.
MOV based protectors are designed to (as you said) shunt enough current to
earth to limit the Voltage rise to manageable limits - where 'Whole house
protection' fails is in Near or Direct strikes (well actually most Lightning
protection regimes are prone to Failures in Direct strikes - just ask any
Telco or Transmitter operator) the other and common Protection Rationale is
to ensure that all incoming and Outgoing wires/connectors are at rouglhy the
same potential.
Most serious Surge protection employs aspects of both however given the High
currents etc involved in Lightning strikes it is actually a very hard call
to shunt enough current to earth in most domestic installations to be
effective - as even Earth itself suffers a Rise in the order of 100,000
Volts in the event of a Lightning strike.

As for Lightning for a Surge arrestor to be anywhere near
effective it needs to reduce and Differential voltage across the
Device and Surge protection built into equipment typically offers
Protection as good as any 'whole house protection'.


Plan A - shun lightening to ground within a foot or two of the equipment,
via a small piece of grounding wire plugged into an outlet.

Not quite -
Plan A shunt lightning around your Electronic equipment by ensuring that any
Potential rise across the device is kept as low as possible close to the
equipment and essentially let your equipment ride out the Strike.

Play B - shunt lightening to ground many feet from the equipment, via a
big
hunking chunk of copper permanently connected to the safety ground point
for
the whole house.

Plan B shunt Lightning to a Ground which will rise to over 100KV above
nominal Earth and then create paths from this Single Earth point to lower
potential points around the House via the house wiring this in fact offers
little if any better protection than MEN mains already has.

It's up to you. ;-)

it is indeed and both Strategies run into serious problems as soon as you
introduce more external wiring - especially if (as is the case with phone
lines) that wiring is not very well Earthed and that really is the advantage
of local adequate surge arrestors - nb for this to have any hope of
providing any protection it needs to be a decent surge supressor and pretty
well nothing beats a hunk of iron with copper wrapped around it.


Fortunately
though Lightning damage from medium to distant Strikes is very rare
via AC mains (Lightning damage via Phone/Data Lines is far far more
common)

I've definately seen major trashing of residences via lightening that
unambigiously came in via the power lines. I've also seen trivial effects
like arcing behind the plastic plates of AC outlets due to nearby
lightening
strikes.

however for each event like this there are hundreds of cases of Lightning
coming in via a Phone or data line.

And in the event of a near or Direct strike almost no amount
of Practical Lightning protection will suffice - TV Transmitters have
typically the best Lightning Protection available and even they
frequently suffer Lightning damage.

They get direct strikes, by the bucketload. Something about that 1000 foot
plus tower. Not the same as what I was addressing.

Well yes and no the basic Idea is still the same - with these beasties the
trick is still to ensure that all the equipment remains at the same
potential (or as close to it as possible) and rides out the strike - hence
the room is typically a metal box with a single tie to a very comprehensive
earth system - often covering 1/2 an Acre or more

The most Effective Surge or
Lightning Protection is simply a nice hefty 1:1 Isolation Transformer
- A Torodial works best as Phil suggests - with a Primary Fuse or
Breaker and keep any Phone lines entering this protected zone
disconnected if there is any threat of a Storm.

If you want to fight whole house surge protecting, be my guest. After all
its your house at stake, not my house or the houses of my friends.

whole house Protection is inexpensive.

For the record, I live in an urban area. I have seen neighbor's houses
seriously damaged by lightening strikes to trees, which are the tallest
entities in my neighborhood. The house power system was affected in all
cases.

Near and or Direct strikes affect everything pretty well.

In this situation, a whole house protector would work a little
differently.
It would keep the strike from propagating out from the circuit box. In
this
mode, the protector would force tripping of the circuit breaker for the
the
branch circuit that was struck by lightening. Items on that circuit would
still probably get fried, but the rest of the house would still be
protected.

I disagree - first the Whole house protector is not going to trip the rather
leisurely breakers for probably 20 odd mS the strikes will be over in - lets
say 6 x 100uS strikes - 7-800uS. Secondly the whole House protector if it
does go hard short for the strike (MOVs don't of course but that is another
story) will then direct say 1/10th of a typical 100,000 odd Amp strike to an
Earth stake where less than 10 Ohms is considered good. well Ohms law is not
difficult to apply and this gives us an EPR (GPR for the Americans) of
100,000 Volts this of course is enough Potential Difference to cause current
flow through the Building wiring to other attractive earth points around the
House. In short Widespread damage.

OTOH for Localised surge supression you are merely trying to keep the
Potential Difference across your equipment to a minimum and by keeping your
Protection local you are essentially letting all your equipment ride out the
Strike.

The real problem with most Plug in surge supression is that it is usually
made down to a Price rather than up to a standard and people buy cheap and
crappy surge arrestors and are then surprised when they fail to provide any
protection at all. Also remember that with the Very high currents and Energy
levels involved there is pretty well no such thing as Complete 100%
effective Surge/Lightning Protection and these Devices are really best being
considered as a last line of Defence for when you cannot or forget to unplug
equipment during a Thunderstorm.

On 6 Sep 2004 19:27:18 -0700, (Tom Paul) wrote:

I'll tell you what most folks miss though are the other Cables coming
into the house...phones, television coax..etc. Any wire coming in
from the outside can bring surges to your stuff. There are 5-10
dollar units to install where those lines come into your house that
are really good to get too. YOu don't need one on every bit of
equipment.

Several years ago we had a lightning strike outside our house. The
cheap surge protector sacrificed its life protecting the motherboard
and printer, but the phone line was unprotected and my answering
machine and the modem inside the computer got fried.

Willie K. Yee, M.D. http://users.bestweb.net/~wkyee
Developer of Problem Knowledge Couplers for Psychiatry http://www.pkc.com
Webmaster and Guitarist for the Big Blue Big Band http://www.bigbluebigband.org

tttttttttttttt (Willie K.Yee, M.D.) wrote in
:

Several years ago we had a lightning strike outside our house. The
cheap surge protector sacrificed its life protecting the motherboard
and printer, but the phone line was unprotected and my answering
machine and the modem inside the computer got fried.

Reminds me of the time at the CDC where the not-bright electrician wired
220V into the network panel. Killed hundreds of NIC's and motherboards.

"Willie K.Yee, M.D." wrote in message
...
On 6 Sep 2004 19:27:18 -0700, (Tom Paul) wrote:

I'll tell you what most folks miss though are the other Cables coming
into the house...phones, television coax..etc. Any wire coming in
from the outside can bring surges to your stuff. There are 5-10
dollar units to install where those lines come into your house that
are really good to get too. YOu don't need one on every bit of
equipment.

Several years ago we had a lightning strike outside our house. The
cheap surge protector sacrificed its life protecting the motherboard
and printer, but the phone line was unprotected and my answering
machine and the modem inside the computer got fried.

Willie K. Yee, M.D. http://users.bestweb.net/~wkyee
Developer of Problem Knowledge Couplers for Psychiatry http://www.pkc.com
Webmaster and Guitarist for the Big Blue Big Band
http://www.bigbluebigband.org



The power, cable, etc., lines outside of your house need treatment as they
enter the house, but, as many amateur radio buffs have discovered over the
years, just a very long power cord, unplugged from the wall and lying about,
is capable of picking up enough EMP from a nearby strike to damage today's
consumer electronic equipment.

Ed Cregger, NM2K

tttttttttttttt (Willie K.Yee, M.D.) wrote in
:

On 6 Sep 2004 19:27:18 -0700, (Tom Paul) wrote:

I'll tell you what most folks miss though are the other Cables coming
into the house...phones, television coax..etc. Any wire coming in
from the outside can bring surges to your stuff. There are 5-10
dollar units to install where those lines come into your house that
are really good to get too. YOu don't need one on every bit of
equipment.

Several years ago we had a lightning strike outside our house. The
cheap surge protector sacrificed its life protecting the motherboard
and printer, but the phone line was unprotected and my answering
machine and the modem inside the computer got fried.

Willie K. Yee, M.D. http://users.bestweb.net/~wkyee
Developer of Problem Knowledge Couplers for Psychiatry
http://www.pkc.com Webmaster and Guitarist for the Big Blue Big Band
http://www.bigbluebigband.org


One of my friends had lightning hit is phone line. It blew a 2 inch hole in
the back of his phone and vaporized all the phone wiring. The lightning
jumped from the metal phone chassis into the metal desk it was on damaging
everything electronic on the desk and then jumped into the AC through the
back of the desk and took out an electric stove element and a ceiling fan.

He sold the desk and bought a wooden one afterward.

Simple surge protection is no help when you get hit that hard.

-Bruce

On Sun, 12 Sep 2004 11:21:39 GMT, tttttttttttttt
(Willie K.Yee, M.D.) wrote:

Several years ago we had a lightning strike outside our house. The
cheap surge protector sacrificed its life protecting the motherboard
and printer, but the phone line was unprotected and my answering
machine and the modem inside the computer got fried.

The EMP from lightning does strange stuff. I once saw an old-fashioned
three CRT television projector, likely a Kloss, that was near a
lightning strike.

None of its old-fashioned electronics were hurt, but there was no
image in the CRTs. The soft iron shielding around the CRTs had
gotten such a magnetic charge that the electron beams were
completely off the targets, and a Han-d-mag restored things.

Chris Hornbeck

"Bruce" wrote in message
...
tttttttttttttt (Willie K.Yee, M.D.) wrote in
:

On 6 Sep 2004 19:27:18 -0700, (Tom Paul) wrote:

I'll tell you what most folks miss though are the other Cables coming
into the house...phones, television coax..etc. Any wire coming in
from the outside can bring surges to your stuff. There are 5-10
dollar units to install where those lines come into your house that
are really good to get too. YOu don't need one on every bit of
equipment.

Several years ago we had a lightning strike outside our house. The
cheap surge protector sacrificed its life protecting the motherboard
and printer, but the phone line was unprotected and my answering
machine and the modem inside the computer got fried.

Willie K. Yee, M.D. http://users.bestweb.net/~wkyee
Developer of Problem Knowledge Couplers for Psychiatry
http://www.pkc.com Webmaster and Guitarist for the Big Blue Big Band
http://www.bigbluebigband.org


One of my friends had lightning hit is phone line. It blew a 2 inch hole
in
the back of his phone and vaporized all the phone wiring. The lightning
jumped from the metal phone chassis into the metal desk it was on damaging
everything electronic on the desk and then jumped into the AC through the
back of the desk and took out an electric stove element and a ceiling fan.

He sold the desk and bought a wooden one afterward.

Simple surge protection is no help when you get hit that hard.

-Bruce


You are correct. With every precaution in place, other than living inside of
a Faraday cage, there really is no way to be completely protected from
lightning.

Ed Cregger