Laptop on AC over a surge protector? - Page 2

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Re: Laptop on AC over a surge protector?

It all depends on the batteries (in the UPS), but modern laptops draw an
average of about 100 watts, and you also need to run the cable or DSL
modem.  Most low-power UPS' won't give you anywhere even close to 24
hours at that rate of draw.  Think about it, the average laptop battery
is about 4000mah, give or take, and runs the laptop directly for an
average of 2-3 hours.  The average UPS battery in this class of UPS is 7
amp hours (7000 mah), so at best you should expect about 6 hours (and
that's really pushing it), but in fact you are running through two
switching power supplies (the UPS itself and the laptop's AC adapter)
that both have efficiencies in the 60% to 80% range, and in practice you
don't get anywhere near 6 hours of use from a typical UPS in this
product class.

Al Dykes wrote:
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Re: Laptop on AC over a surge protector?

John Doue wrote:
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  Phone lines already have an effective 'whole house' protector
installed by your telco.  So effective and so inexpensive as to be
installed for free and required by code.   But like all shunt mode
protectors, it is only as effective as an earth ground electrode that
you have provided.

  Somehow APC, et al  would have you ignorant of so many facts such as
the existing telephone line protector.  They have you believing that
the protector is a layer of protection.  Protector does not provide the
protection.  *Protector* is simply a connection device to protection.
*Protection* is earthing.  Plug-in protectors hope you will never learn
that earthing is essential - profits are too high.

  Werner R Schilling demonstrates protection he found in his UPS.  Did
you read the very first post?
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 So where is this layer of protection?  He found "mains power cable
... connected directly to the "surge protected" outlets with NOTHING in
between."   Where is this protection layer?

  The protection is in shunt mode devices.  Devices that requires a
'less than 10 foot' connection to earth.  Why is APC so terse on what
it does?  Did you really believe that $80 surge protector would stop
what three miles of sky could not?  They hope you believe that myth.
They hope you don't know about an existing telephone line protector and
necessary earth ground.

  Meanwhile effective protector from credible manufacturers to protect
everything in a house are from Lowes, Home Depot, and electrical supply
houses.  Available for about $50.  Effective protection for about $1
per protected appliance. You paid $80.00 per appliance. Effective
protector that has a dedicated earthing wire and therefore makes a
connection to protection.

  Each layer is defined earth ground.  Secondary protection layer
defined by a building's earthing electrode.  Primary protection layer
is defined by this:

  APC provided no protection layer.  Too far from earth ground.

   Any protection effective when adjacent to the laptop is already
inside the laptop. So that  internal protection is not overwhelmed, you
must install and properly earth a 'whole house' protector.  IOW you
must install the missing secondary protection layer. Listed previously
were brand names of responsible manufactures:   Square D, Leviton,
Intermatic, Siemens, Cutler-Hammer, and GE.  Notice APC is not on the
list.  APC fears to even discuss earthing - the most essential
component in a protection system.

  Those promoting ineffective plug-in protectors for $80.00 will
routinely forget to mention protection even installed on phone lines.
Effective protection starts with inspection of building's earthing
electrode and how connections to that electrode are made.  Those who
instead need an expensive 'box' solution will assume that 'box' will
stop what three miles of sky could not.  No earth ground means no
effective protection.  APC will not even discuss earthing.

Re: Laptop on AC over a surge protector?

Werner R Schilling wrote:
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  Add some facts that have not yet been discussed.  First point) A
typically destructive surge is not stopped by three miles of sky. Why
would a fuse or an inductor stop what three miles of sky could not?
That is the myth promoted by plug-in protectors.   Properly noted is
that all appliances already contain internal protection.  Any
protection that would be on its power cord is already inside the
appliance.  But this internal protection can be overwhelmed by one type
of transient if not earthed before entering the building.

  Look at specifications for surge protectors - UPS or power strip.
Makes little difference whether it is $5 or $100.  They don't even
provide numbers from protection for each type of transient.  Look for
yourself.  Where do they list each type of transient and then provide
protection numbers for that transient?  They don't because they hope
you don't learn:  it protects only from a transient that typically does
not do damage AND that is made irrelevant by protection already inside
the appliance.

  Second point) Telephone line already has a 'whole house' protector
installed, for free, by your telco.   Surges enter on phone lines?
Rarely.  First because those AC electric wires act as catenary
protection (lightning strikes AC mains and therefore not phone lines).
 Second, the phone line already has an earthed 'whole house' protector.

  Why does the telco install it for free?  Because protector is so
effective and so inexpensive.  It is located where effective protector
must be located an essential and short connection to earth.

  That introduces point three) How does effective surge protection
work?   If three miles of sky could not stop a surge, then how did we
routinely install effective protection from direct strikes even 50
years ago?  Why does your telco not shutdown phone service during every
thunderstorm to protect their $multi-million computer?  Why do
televisions and FM radio stations atop the Empire State Building not
shutdown to avoid 25 direct strikes annually?

  Protection was demonstrated by Ben Franklin in 1752.  Lightning seeks
a conductive path to earth:  a wooden church steeple.  To protect that
steeple, Franklin gave lightning an electrically shorter path to earth:
 Ben Franklin lightning rod.  Does the lightning rod (sharp or blunt)
define protection?  Of course not.  Protection is about shunting - an
electrically shorter path to earth.  Protection is defined by quality
oft earth ground and its connection.

  How does that telco surge protector work?  It makes a less than 10
foot connection to single point earth ground.  Again, earthing defines
protection.  The protector is only a connection to protection - earth.
We don't stop, block, or absorb surges as others will claim to promoted
plug-in protectors.  We shunt (divert, connect) a surge to what it
wants so that lightning will not find earth ground, destructively,
through appliances.

  Point four) Where do we find effective protection?  As noted, the
telco already installs a 'whole house' protector for free.  Protector
that is only as effective as its earth ground Building's earthing
electrode must meet and exceed post 1990 National Electrical Code
requirements.   Notice what is essential to effective protection -

  Every utility wire dumps a typically destructive surge into earth
before entering a building.  That means cable TV coax also must connect
'less than 10 feet' to this earthing electrode.  Notice no
protector required for cable TV protection.  That earthing is made
without a protector - a direct hardwire to the $2 ground block that
every cable company is required, by NEC to install  (you provide the
single point earthing electrode).

  The most common source of surges that overwhelm appliance internal
protection:  AC electric (even if wires are underground).  Effective
protectors are sold with brand names recognized by electrical people as
the most responsible manufacturers:  Square D, Leviton, Intermatic,
Siemens, Cutler-Hammer, and GE.  These effective 'whole house'
protectors for AC electric are sold in Home Depot, Lowes, and
electrical supply houses.  Effective protectors have not been found in
Sears, Circuit City, Staples, Radio Shack, Wal-Mart, Office Depot, Best
Buy, or your grocery store.

  How to identify an ineffective protector?  1) No dedicated earthing
wire, and 2) manufacturer avoids all discussion about earthing.

  No earth ground means no effective protection.  A surge not earthed
before it enters the building will find earth, destructively, via
household appliances.  If permitted inside the building, a surge may
overwhelm protection already inside appliances.

Re: Laptop on AC over a surge protector?

Not all destructive surges are full-bore lighting strikes.  Sometimes
it's a surge of 500 to 2500 volts for a few hundred nanoseconds caused
by the magnetic field around your air conditioning or refrigerator
compressor motor collapsing as the motor cuts off.  You are correct that
almost nothing -- NOTHING -- is going to stop a full-bore lightening
strike, but that's not the majority of surges, either.

Many surge protectors do provide numerical ratings of the number of
joules of energy that they can absorb.

Also, simple fact is that more failures do occur on the modem (phone
lines) than to the computers themselves (and sometimes a surge that
enters via the modem gets to the motherboard).  Ask anyone who actually
services PCs.  The number of modems that take a phone line hit is very
large relative to the number of computers that take a power line hit.

w_tom wrote:
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Re: Laptop on AC over a surge protector?

Barry Watzman wrote:
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  If that appliance generated surge existed, then we were all trooping
daily to a hardware store to replace dimmer switches, electronic
thermostats, smoke detectors, clock radios, etc - all destroyed by the
surge.  If that appliance generated surge existed, then that appliance
was destroying itself.  Those appliance generated surges were myths put
forth by plug-in protector promoters - hoping we would forget even
GFCIs that were not damaged.  Yes, even a GFCI is electronics that
would be destroyed by such appliance generated surges - if they

  If appliance is generating a destructive transient, then protection
must be installed in that appliance - or appliance must be removed as a
threat to human safety.  Household wires are only rated for 600 volts -
not 2000 volts supposedly generated by an air conditioner or

  Appliance contains internal protection that makes even trivial motor
generated transients (called noise) irrelevant.  Internal protection
can be overwhelmed by a typically destructive type of transient -
lightning.  We install 'whole house' protectors to make lightning
transients irrelevant.  It also would have household generated
transients irrelevant.

  Each protection layer is defined by its single point earth ground.
Defined in a previous post was secondary protection.  AC electric and
telephone 'whole house' protectors connected to 'homeowner provided'
earthing electrode is secondary protection.  Coax and satellite dish
cable earthed directly using a ground block to same electrode is also
secondary protection.  Earthing electrode defines a secondary
protection system.

   Primary protection 'system' is provided by the utility and
should be homeowner inspected:

Re: Laptop on AC over a surge protector?

Sorry, but generated surges do exist.  There's a lot of luck involved,
things can happen (just as an example, two major appliances shut of at
exactly the same moment, and that moment just happens to be at the exact
peak of the power line sine wave).  Shit (and surge) happens.  But
normal household devices (including computers) can absorb ALMOST all of
the normal surges.  Almost.

[By the way, I've lost dozens of "X10" dimmers when the light bulbs that
they were controlling blew.  When a lightbulb blows, sometimes there is
a direct short across the AC power lines .... until the innards of the
bulb are destroyed.  We usually worry about voltage surges, but that
current surge can be huge, many tens of amps, although of short
duration.  Their inability to withstand such expected surges was one of
the things that soured me on X10 controllers.]

w_tom wrote:
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Re: Laptop on AC over a surge protector?

Barry Watzman wrote:
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  Well, then you are routinely replacing smoke detectors, bathroom
GFCIs, electronic thermostat, television, dimmer switches, alarm
system, clock radio, dish washer, and appliance that is creating the

  Meanwhile, a properly earthed 'whole house' protector would make that
appliance generated surge irrelevant.  One protector, sufficiently
sized, means everything in a building is sufficiently protected from a
typically destructive lightning strike - and would also make appliance
generated surges irrelevant.  That is a protector that costs about $1
per protected appliance.  Superior solution AND it costs less money.
But again, earthing to exceed post 1990 NEC requirements is also

  Meanwhile Werner R Schilling posted:
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  Of course. Did you think it was a series mode protector?  Did you
think it would somehow stop what three miles of sky could not?  It is a
shunt mode protector. Shunts - those MOVs - are effective if making a
'less than 10 foot' connection to earth.  Oh.  No dedicated eathing
wire?  Yes, they sort of forget to mention earthing since effective
protection is not claimed.  No wonder its MOVs are also undersized.
MOVs are installed to claim protection; not provide effective
protection.  And not connected to earth.  But still - it is surge
protection. You cannot deny that.   You are not supposed to notice
little details such as no protection claims in its numerical
specifications, too small, and no earth ground.  You are supposed to
*assume* it is a series mode protector.  They are marketing to others
who only read propaganda in glossy sales brouchures and who believe
myths from those without technical knowledge. .

  No earth ground means no effective protection. Just another little
fact they forget to mention.

Re: Laptop on AC over a surge protector?

w_tom wrote:
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The best information I have seen on surge protection is at
- w_tom provided the link to this guide
- the title is "How to protect your house and its contents from
lightning: IEEE guide for surge protection of equipment connected to AC
power and communication circuits"
- it was published by the IEEE in 2005
- the IEEE is the dominant organization of electrical and electronic
engineers in the US

A second guide is
- this is the "NIST recommended practice guide: Surges Happen!: how to
protect the appliances in your home"
- it is published by the National Institute of Standards and
Technology, the US government agency formerly called the National
Bureau of Standards
- it was published in 2001

Both guides were intended for wide distribution to the general public
to explain surges and how to protect against them. The IEEE guide was
targeted at people who have some (not much) technical background.  Read
one (or both) to understand surges and protection

Both say plug-in surge suppressors are effective.

All interconnected devices, like a computer and printer, need to
connect to the same surge protector. If a device, like a computer, has
external connections like phone or LAN, all those wires have to run
through the surge suppressor for protection. This type of suppressor is
called a surge reference equalizer (SRE) by the IEEE (also described by
the NIST). The idea is that all wires connected to the device (power,
phone, CATV, LAN, ...) are clamped to a common ground at the SRE. The
voltage on the wires passing through the SRE are held to a voltage safe
to the connected device.

The primary action is clamping, not shunt mode, series mode, filtering,
or earthing. Since this viloates w_'s religous principle that "No earth
ground means no effective protection" w_ apparently can't read and
understand these guides.


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