Lightning and computer?

[Susan]

I was asked opinion about computer in office of organization. I suggested
that since we often have lightning storms and even though there is a surge
protector, the phone line should be unplugged and I would also unplug the
computer from the surge protector before closing the office up.

One lady told me that she never unplugs her computer and she never unplugged
her stove or refrigerator but she always turned off the surge protector and
left everything plugged in.

Please give your opinion.

Thanks,
Susan

 

[Bob Day]

I was asked opinion about computer in office of organization. I suggested
that since we often have lightning storms and even though there is a surge
protector, the phone line should be unplugged and I would also unplug the
computer from the surge protector before closing the office up.

One lady told me that she never unplugs her computer and she never unplugged
her stove or refrigerator but she always turned off the surge protector and
left everything plugged in.

Please give your opinion.

Better safe than sorry. Unplug everything, especially the computer,
and very definitely the phone line. You might as well unplug the
surge protector also to protect it too.

-- Bob Day
http://bobday.vze.com

 

[Richard Urban]

Lightning has more than enough electrical "potential" to jump the small gap
created when the switch in the surge protector is turned off. It depends
mostly upon whether the pole transformer you are connected to is properly
grounded. Even then, if the lightning strikes the wires in front of your
residence, you may still be taken down.

If it isn't plugged in - you are safe.

--
Regards,

Richard Urban

aka Crusty (-: Old B@stard

If you knew as much as you thought you know,
You would realize that you don't know what you thought you knew!

 

[Al Dykes]

Better safe than sorry. Unplug everything, especially the computer,
and very definitely the phone line. You might as well unplug the
surge protector also to protect it too.

-- Bob Day
http://bobday.vze.com

get a small UPS that also filters you phone line and be happy. It
needs to be replaced every couple years.

Backup your system frequently. There 99 other things that will kill
your system just as dead. Don't fixate on lightning.

If you are in a steel frame highrise building with undeground power
and phone lines only a direct strike on your building will cause a
spike. If you are in a small building in the suburbs in Florida you
need to to take more care with surget protection and grounding.

You can't buy a real surge protector for less than $10. Anything
cheaper is just an extension cord. A real surge protector has a
limited lifetime if you are in lightning country. It will have an
idiot light to inform you when it's used up. The lmap on an extension
cord is just an on/off indicator.

You can get an electrician to install whole-house surge protection in
your electrical panel.

 

[Neil]

I was asked opinion about computer in office of organization. I suggested
that since we often have lightning storms and even though there is a surge
protector, the phone line should be unplugged and I would also unplug the
computer from the surge protector before closing the office up.

One lady told me that she never unplugs her computer and she never unplugged
her stove or refrigerator but she always turned off the surge protector and
left everything plugged in.

Please give your opinion.

Thanks,
Susan

I worked for a company that was struck by lightning. The surge came in
through the phone line and took out all the computers, phones, fax machine,
and the laser printers.

best to unplug if you can!

 

[Leythos]

I worked for a company that was struck by lightning. The surge came in
through the phone line and took out all the computers, phones, fax
machine, and the laser printers.

It has a lot to do with things you may not control. In my area the
utilities are underground, we've never seen a static spike and seem to
only get drop-outs. About 6 blocks from here the lines are above ground
and I've talked with people that have lost appliances and other items
hooked only to the power lines.

When it comes to my computers (office or home), I install a quality APC
USP and filter the AC and Voice lines when used. I do not unplug anything
during storms and have never experienced a problem due to it.

 

[Galen]

In Leythos <[email protected]> had this to say:

My reply is at the bottom of your sent message:

It has a lot to do with things you may not control. In my area the
utilities are underground, we've never seen a static spike and seem to
only get drop-outs. About 6 blocks from here the lines are above
ground and I've talked with people that have lost appliances and
other items hooked only to the power lines.

When it comes to my computers (office or home), I install a quality
APC USP and filter the AC and Voice lines when used. I do not unplug
anything during storms and have never experienced a problem due to it.

My home is well protected (I have to have it that way as I live on a
mountain with erratic power from the lines at best) and thus I never turn
anything off. In fact during lightning storms or the like I tend to sit here
still using the computer. The only time I'm not using the PC I'm either not
at home, the phone lines are out due to a snow storm, or I'm sleeping. Well,
okay, sometimes I eat and bathe but not then I'm not gone long enough to be
considered 'away' I guess.

Assuming that you don't have these same measures in place it's best that you
unplug everything within reach that's important to you.

Galen

 

[NobodyMan]

get a small UPS that also filters you phone line and be happy. It
needs to be replaced every couple years.

You don't need to replace the UPS every couple of years, just the
battery inside it.

 

[Leythos]

You don't need to replace the UPS every couple of years, just the
battery inside it.

Quite true, but the cost of a new unit is often cheaper than the cost of a
battery - at least here in Ohio I can get a 900va UPS, new, for $65, and
the battery costs about that amount to replace.

 

[Al Dykes]

Quite true, but the cost of a new unit is often cheaper than the cost of a
battery - at least here in Ohio I can get a 900va UPS, new, for $65, and
the battery costs about that amount to replace.

And if you _are_ getting surges then the protective circuitry in looses
it's effectiveness.

 

[w_tom]

Most people never learned principles of of protection.
Their knowledge comes from 'half truths' promoted on retail
store shelves. This post will be long because it is
introducing fundamental concepts of protection rarely
discussed by those who 'just know - facts be damned'. It will
directly confront those popular urban myths. It will be long
because myths are numerous and aggressively promoted.
Questions and doubts will often be answered using third party
and industry sources. This only introduces a technology well
proven by the 1930s and that operates without failure in
virtually every town. Well proven where failure is not an
option. Protection that costs so much less than overhyped
plug-in protectors and UPSes.

Ham radio operators would disconnect the antenna and suffer
damage. They would disconnect the antenna, put the lead
inside a mason jar, and still suffer damage. Then they
connected the antenna to an earth ground. Not just any
ground. Earth ground. No more damage. Disconnection is not
an effective solution.

Ben Franklin demonstrated same in 1752. Diverting so that
lightning did not find earth ground via a church steeple. One
does not stop, block, or absorb lightning. Only mythical
plug-in protectors claim to do that. A tiny protector is
going to stop what 3 miles of sky could not? Effective
protection earths. Diverts before a transient can even enter
the building. Diverting to earth has always been the well
proven and effective protection - be it a lightning rod or
protection on every incoming utility wire.

Your phone company shuts down when storms approach.
Obviously they must disconnect to protect a $multi-million
computer that connects to overhead wires everywhere in town.
Oh? They don't shut down? And they don't use plug-in
protectors? Solution: every line is earthed before it gets
near to that computer. Earthing is best accomplished 50
meters (150 feet) before that wire gets to transistors. This
being a far less expensive and well proven solution. A
technology defined in 1930s research papers. And yet even
here, notice the numerous posters who fail to address what has
long been effective protection.

Ignore those who promoted names like APC, Tripplite,
Panamax, Belkin, or Monster Cable. They know not how science
works. They promote junk science. Responsible products have
names like Square D, Furse, Leviton, Erico, Intermatic, Cutler
Hammer, Polyphaser, GE, and Siemens. What do effective
protector do? Same as Franklin did in 1752. Earth that
incoming transient before it can enter a building.

Would you spend $15 or $50 on every electronic appliance?
Then you have money to burn. Effective 'whole house'
protector costs on the order of $1 per protected appliance AND
remains fully functional after each transient. For
residential protection, responsible stores such as Home Depot
(Intermatic IG1240RC) and Lowes (Cutler Hammer and GE) sell
effective 'whole house' protectors. Phone line has long
contained such protectors inside the NID. Why? Its so
inexpensive and so effective.

But again, the lessons demonstrated by Franklin, ham radio
operators, and the telco switching computer. They earth each
incoming utility wire before a transient enters a building.
Do 911 Operators remove headsets when thunderstorms arrive?
Again, effective protection so long proven: earthing.
Earthing means a no destructive transient in the headset (upon
the head) of that 911 operator.

Posted previously were myths that a magic box (UPS or power
strip: both contain the same protector circuit) would protect
electronics. One was so technically ignorant as to claim the
UPS will "filter" phone lines. Even the manufacturer does not
make that claim. That UPS was going to stop what 3 miles of
sky could not? A filter will do what a disconnect cannot even
accomplish? A filter that will stop a transient but will not
stop phone conversation? Those useless plug-in manufacturers
have so many brain washed by urban myths.

Polyphaser is an industry benchmark. Polyphaser app notes
are highly regarded by industry professionals. What does
Polyphaser discuss - their products? Of course not.
Polyphaser discusses THE most critical component in every
protection system: single point earth ground.
http://www.polyphaser.com/ppc_ptd_home.aspx

Effective protection: every incoming utility first connects
short and direct to an earth ground either by direct hardwire
(cable TV and satellite dish) or via a 'whole house' protector
(telephone and AC electric). What is the one component that
must be in every protection system? Single point earth
ground. What is never even discussed by those who recommend
that mythical UPS or power strip solution? Single point earth
ground.

Which wire is most often struck? Wire highest on pole is a
direct connection into every computer, fax machine, smoke
detector, bathroom GFCI, furnace controls, etc. What invites
lightning to find earth ground via your electronics? AC
electric is the one utility wire that typically has no
effective protection. Why? We still build as if the
transistor did not exist.

You must install the effective protection. That means
building must meet or exceed post 1990 earthing requirements
of the National Electrical Code. Every incoming AC wire
connects less than 10 feet to that single point earth ground
via a properly sized 'whole house' protector. Effective
devices are even available from Home Depot and Lowes (see
above) but have never been seen in Kmart, Sears, Staples,
Office Max, Walmart, Target, Radio Shack, Tru-Value, or
Circuit City. Those who promote ineffective protectors such
as Panamax, APC, Tripplite, or Monster Cable will also avoid
discussing another critical number: joules.

Effective protection exists inside electronic appliances.
Any protection effective on that power cord is already inside
that appliance. Internal appliance protection that can be
overwhelmed if a human fails to install properly sized and
properly earth protection systems - ie the 'whole house'
protector.

Meanwhile, how to identify the ineffective protector: 1) no
dedicated connection to earth ground and 2) manufacturer
forgets to mention the most critical component of every
protection system: earth ground.

Again, many would advocate an ineffective plug-in protector
without any idea what that protector will do. They don't even
know of the protection already inside appliances. They
recommend plug-in protectors that can even contribute to
damage of the adjacent and powered off computer. Protectors
that cost tens of times more money per protected appliance.
Protectors that are so often grossly undersized as to fail on
a first transient. Bottom line: a protector is only as
effective as its earth ground.

 

[Leythos]

Effective protection: every incoming utility first connects
short and direct to an earth ground either by direct hardwire (cable TV
and satellite dish) or via a 'whole house' protector (telephone and AC
electric). What is the one component that must be in every protection
system? Single point earth ground. What is never even discussed by
those who recommend that mythical UPS or power strip solution? Single
point earth ground.

My house was built in 1972, it has a very nice, long, copper rod about 9"
from the wall of the house, driven into the earth, that rod connects to
the power panel earth ground bar, and that connection also connects to
incoming shields for Cable TV. As for the phones, they connect to a small
UPS at the incoming point to the house, which then go through the UPS to
the rest of the house.

Now, I've seen your posts in other threads, at least I think it was you,
but I'm going to say, as an electrical engineer, as a person working with
sensitive electronic parts and circuits, as a person with 20+ computers in
their home, that a simple UPS does indeed protect the hardware attached to
it, I've seen it protect my systems/devices while my neighbors were not
protected.

You can spout theory all you want, spout document after document, but you
can't disprove real-life experiences that indicate you are wrong about the
merits of a quality UPS in an environment with a quality earth ground
inside the home. Every home in our neighborhood has the same power system,
same wiring methods, and many experience outages, dips, surges, even
lightning issues. While I've talked with neighbors that have lost devices
during a storm, only the ones that didn't have a UPS lost devices, the
ones that had a UPS during the same period, didn't lose any devices.

Now, before you go spouting your same old diatribe, explain how my
real-life experiences is false.

 

[Al Dykes]

My house was built in 1972, it has a very nice, long, copper rod about 9"
from the wall of the house, driven into the earth, that rod connects to
the power panel earth ground bar, and that connection also connects to
incoming shields for Cable TV. As for the phones, they connect to a small
UPS at the incoming point to the house, which then go through the UPS to
the rest of the house.

Now, I've seen your posts in other threads, at least I think it was you,
but I'm going to say, as an electrical engineer, as a person working with
sensitive electronic parts and circuits, as a person with 20+ computers in
their home, that a simple UPS does indeed protect the hardware attached to
it, I've seen it protect my systems/devices while my neighbors were not
protected.

You can spout theory all you want, spout document after document, but you
can't disprove real-life experiences that indicate you are wrong about the
merits of a quality UPS in an environment with a quality earth ground
inside the home. Every home in our neighborhood has the same power system,
same wiring methods, and many experience outages, dips, surges, even
lightning issues. While I've talked with neighbors that have lost devices
during a storm, only the ones that didn't have a UPS lost devices, the
ones that had a UPS during the same period, didn't lose any devices.

Now, before you go spouting your same old diatribe, explain how my
real-life experiences is false.

Well Said.

There are many things that can kill your PC just as dead as a
lightning strike, and not all power surges are caused by lightning.
Don't fixate on one threat. Full offsite backups are the only real
protection against lightning, or anything else.

A small UPS addresses so many potential risks properly that even if it
isn't the unachievable, theoretical perfect lightning protection you are
much better off for having one.

full house protection was mentioned in this thread (by me). I think
it's a good thing but it does not eliminate the need for a small UPS
on an important PC.

If your house takes a direct hit there _will_ be damage, even with the
ideal grounding system.

 

[Leythos]

Well Said.

There are many things that can kill your PC just as dead as a lightning
strike, and not all power surges are caused by lightning. Don't fixate
on one threat. Full offsite backups are the only real protection
against lightning, or anything else.

A small UPS addresses so many potential risks properly that even if it
isn't the unachievable, theoretical perfect lightning protection you
are much better off for having one.

full house protection was mentioned in this thread (by me). I think it's
a good thing but it does not eliminate the need for a small UPS on an
important PC.

If your house takes a direct hit there _will_ be damage, even with the
ideal grounding system.

I can see it now, people following the chaps recommendations: Lets see
jimbob and his neighbor billybob want follow his direction so they
remember that he said to single point earth ground everything, so that
means we take this here #10 wire from that ground post and attach it to
the big shiny power bar in the electrical panel....zzzzzzzt, bang......
Hello, 911 Operator, what is your emergency.......

 

[w_tom]

A UPS adjacent to that ten foot earth ground rod would
provide effective protection. Building wide UPSes typically
includes the 'whole house' protector. Protection not found
inside plug-in protectors. Somehow, these plug-in
manufacturers want you to believe that $100 item does what a
$5000 item does.

As any electrical engineer knows - wire impedance means
effective protector must make a short (ie 'less than 10 foot')
connection to the good earth ground. Real (building wide)
UPSes include such protection due to that short earthing
connection. The plug-in UPS does not even claim to provide
such protection.

 

[Leythos]

A UPS adjacent to that ten foot earth ground rod would
provide effective protection. Building wide UPSes typically includes
the 'whole house' protector. Protection not found inside plug-in
protectors. Somehow, these plug-in manufacturers want you to believe
that $100 item does what a $5000 item does.

As any electrical engineer knows - wire impedance means
effective protector must make a short (ie 'less than 10 foot')
connection to the good earth ground. Real (building wide) UPSes include
such protection due to that short earthing connection. The plug-in UPS
does not even claim to provide such protection.

And my cheap, $100 APC UPS, provides all the protection needed in my
properly wired house to protect my equipment connected to it. Short of a
direct strike, my systems are protected.

Oh, and impedance, for making a quality short, is based on the size of the
conductor - which means I can use a #6 for a longer distance than a #14.

How about doing the reply at the BOTTOM of the post so that it follows the
normal Usenet methods for posting/replying.

 

[NobodyMan]

And if you _are_ getting surges then the protective circuitry in looses
it's effectiveness.

If it's effectiveness is "loose" then simply tightening it down will
fix the circuitry. You probably already own the wrench or screwdriver
to do this, so it's a pretty cheap repair.

 

[DevilsPGD]

In message <[email protected]> Leythos

Now, I've seen your posts in other threads, at least I think it was you,
but I'm going to say, as an electrical engineer, as a person working with
sensitive electronic parts and circuits, as a person with 20+ computers in
their home, that a simple UPS does indeed protect the hardware attached to
it, I've seen it protect my systems/devices while my neighbors were not
protected.

You can spout theory all you want, spout document after document, but you
can't disprove real-life experiences that indicate you are wrong about the
merits of a quality UPS in an environment with a quality earth ground
inside the home. Every home in our neighborhood has the same power system,
same wiring methods, and many experience outages, dips, surges, even
lightning issues. While I've talked with neighbors that have lost devices
during a storm, only the ones that didn't have a UPS lost devices, the
ones that had a UPS during the same period, didn't lose any devices.

Now, before you go spouting your same old diatribe, explain how my
real-life experiences is false.

Simple: A quality consumer grade UPS won't stop a lightning strike.

However, a direct lightning strike isn't all that common for most of us,
especially if you live in an area with underground wiring and with trees
notably taller then your house (or anything else in the immediate area)
-- What is more likely is smaller dips and surges.

A high end consumer grade UPS will do an excellent job of absorbing
minor fluctuations, something a typical earth ground wouldn't even
pretend to do. Nor will an earth ground connector provide my server
room with an hour of uninterrupted power when the mains go out, suffer
brown outs, or spikes as power is restored.

It's not a matter of one or the other, you need both an earth ground as
well as effective surge protection on electronics, plus battery backup
if you want to continue functioning during an outage.

 

[DevilsPGD]

In message <[email protected]> NobodyMan

If it's effectiveness is "loose" then simply tightening it down will
fix the circuitry. You probably already own the wrench or screwdriver
to do this, so it's a pretty cheap repair.

Well said

 

[Al Dykes]

In message <[email protected]> Leythos


Simple: A quality consumer grade UPS won't stop a lightning strike.

A direct lightning strike WILL cause damage unless the building has a
lightning rod system that costs many thousand dollars and even then
lightning doesn't do what you want it to do and fry some electronics.

A lightning strike is much much less probable than a total hard disk
crash. Buy a good UPS/surge protector and do good offsite backups and
put the money you've saved in the bank for a rainy day.

I'm a proponent of whole-building surge protection at the entry panel
and IG-wired recepticles for the computers, but that's not real world
unless I'm involved with new construction.