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Power Surge



 
 
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  #1  
Old August 29th 03, 09:11 AM
David LeBrun
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Posts: n/a
Default Power Surge

Greetings
I'm currently restoring a system that was hit with a power surge where
the following were fried:
PSU
Motherboard
Hard Drive
CDROM
CDRW
Network (PCI)
Audio (PCI)
However the following components from the same system survived:
CPU
RAM (all 3 sticks that were installed)
AGP video
Modem (PCI)
Floppy
Speakers
Monitor
Keyboard/Mouse

I just find it curious that components I thought were sensitive to
voltage like the CPU and RAM would survive while other components
wouldn't. The core on the audio card actually popped (I found the
center of the silicon at the bottom of the case). I keep telling
people to get a UPS or a good surge protector but no one listens until
they have to pay $$$

Anyone else have a horror story to tell?

Dave.

  #3  
Old August 29th 03, 06:17 PM
Vanguard
external usenet poster
 
Posts: n/a
Default

"Ben" wrote in message

lid wrote:
As for surge protectors, they can do SOME good, but the UPS is
the way to go. Particularly if the UPS does a conversion from A/C
to D/C and back to A/C during normal operation. Many of the cheap
ones simply pass through the normal A/C with a relay and then do a
restoration via the battery when it fails.


If I get one of these UPS surge protectors would that mean I could use
my computer during a thunder storm?

thanks,
Ben


Better to install a whole-home surge protector rather than the cheapie
surge protectors you buy at the store. They cost about the same (unless
you need to have an electrician do the wiring for the home surge
arrestor). Then everything in your house is protected. however, surge
arrestors only protect against surges. They don't protect against sags.
Your power supply would have to suck more current to offset the loss in
voltage until the sag became too low (your lights and television will
work but not the switching power supply in your PC). Surge protectors
also do little to condition the line (but then some cheapie UPSes are
just pass-through units, too). I prefer to get a UPS that generates the
power output rather than just pass it through. A UPS with an isolating
transformer is even better but then they get really heavy; mine weighs
60 pounds for the case with transformer and another 60 pounds for the 2
batteries, for a total of 120 pounds (and has true sinusoidal output and
too many other goodies to list, but then it cost as much as a high end
PC). But even a cheapie UPS is usually better than a surge protector.
You could spend $60 on a good point-of-use surge protector (i.e., you
plug it in the wall install of the point-of-entry whole-home surge
arrestor) and hope that it is still working (since many never tell you
when they've gotten fried) or you spend twice that much on a low-end UPS
that protects better. When the power goes out, the surge protector
doesn't do anything. It can be handy to continue computing while the
power is out. You're television don't work so sit at your PC. You can
check the weather, especially if that caused the outage. You can
contact your power company (since calling in puts in the queue with
everyone else trying to report the outage). You can even hook up a
low-power intensity lamp so you can see without having to drain the
batteries in your flashlights. I actually have a small UPS left over
from a prior system used to power the cable modem and a flourscent lamp,
and it's small enough to tote around the house to use elsewhere. Sure
beats sitting in a dark house.

--
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** Share with others. Post replies in the newsgroup.
** If present, remove all "-nix" from my email address.
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  #4  
Old August 30th 03, 12:37 AM
w_tom
external usenet poster
 
Posts: n/a
Default

What is this sag that causes problems? Computer power
supplies are some of the most robust electronics in the
house. AC electric can drop to 90 VAC (for 120 VAC) or 190
VAC (for 230). The computer must operate interrupted. Even
with a full load of peripherals, the computer must power up
just fine when AC mains voltage has sagged that low.

Incandescent bulbs would be at less than 40% intensity and
the computer must work just fine. However many buy power
supplies only on on specification - price - and get what they
paid for. Sags must not damage any computer. However if you
are still using disk filesystems such as FAT, then you still
data destruction from excessive brownouts or blackouts can
occur. Again, the UPS is nice, but not necessary for hardware
protection if computer hardware is properly selected and
installed.

I never use plug-in UPSes or any other grossly overhyped and
ineffective plug-in protectors. I go online during every
thunderstorm. Never shutdown for such storms. Never unplug
anything. Suffered some direct strikes and never suffered
damage. No damage because the technique is same well proven
methods demonstrated in 1930s research papers.

Those plug-in protectors fundamentally violate those
principles. Summary is provided in "Opinions on Surge
Protectors?" on 7 Jul 2003 in the newsgroup
alt.certification.a-plus or
http://tinyurl.com/l3m9

BTW, plug-in surge protector and plug-in UPS use equivalent
circuits to provide the same ineffective protection. There is
no such thing as blocking or stopping a surge even with a
transformer. Transformer can help to divert the surge. But
again, it still requires the well proven 'whole house'
protection 'system'. Yes - a 'system' that includes the most
critical 'system' component - earth ground.

Plug-in UPS serves one primary function - data protection.
Surge protector is defined by its most critical component -
that plug-in protectors just don't have and forget to
mention. Read that above, previous summary discussion for
details.


Vanguard wrote:
"Ben" wrote in message
If I get one of these UPS surge protectors would that mean I
could use my computer during a thunder storm?
thanks,
Ben


Better to install a whole-home surge protector rather than the
cheapie surge protectors you buy at the store. They cost about
the same (unless you need to have an electrician do the wiring for
the home surge arrestor). Then everything in your house is
protected. however, surge arrestors only protect against surges.
They don't protect against sags. Your power supply would have to
suck more current to offset the loss in voltage until the sag
became too low (your lights and television will work but not the
switching power supply in your PC). Surge protectors also do
little to condition the line (but then some cheapie UPSes are
just pass-through units, too). I prefer to get a UPS that
generates the power output rather than just pass it through. A
UPS with an isolating transformer is even better but then they get
really heavy; mine weighs 60 pounds for the case with transformer
and another 60 pounds for the 2 batteries, for too many other
goodies to list, but then it cost as much as a high end PC). But
even a cheapie UPS is usually better than a surge protector. You
could spend $60 on a good point-of-use surge protector (i.e., you
plug it in the wall install of the point-of-entry whole-home surge
arrestor) and hope that it is still working (since many never tell
you when they've gotten fried) or you spend twice that much on a
low-end UPS that protects better. When the power goes out, the
surge protector doesn't do anything. It can be handy to continue
computing while the power is out. You're television don't work so
sit at your PC. You can check the weather, especially if that
caused the outage. You can contact your power company (since
calling in puts in the queue with everyone else trying to report
the outage). You can even hook up a low-power intensity lamp so
you can see without having to drain the batteries in your
flashlights. I actually have a small UPS left over from a prior
system used to power the cable modem and a flourscent lamp,
and it's small enough to tote around the house to use elsewhere.
Sure beats sitting in a dark house.

  #5  
Old August 30th 03, 02:59 AM
Vanguard
external usenet poster
 
Posts: n/a
Default

"w_tom" wrote in message

What is this sag that causes problems? Computer power
supplies are some of the most robust electronics in the
house. AC electric can drop to 90 VAC (for 120 VAC) or 190
VAC (for 230). The computer must operate interrupted. Even
with a full load of peripherals, the computer must power up
just fine when AC mains voltage has sagged that low.

Incandescent bulbs would be at less than 40% intensity and
the computer must work just fine. However many buy power
supplies only on on specification - price - and get what they
paid for. Sags must not damage any computer. However if you
are still using disk filesystems such as FAT, then you still
data destruction from excessive brownouts or blackouts can
occur. Again, the UPS is nice, but not necessary for hardware
protection if computer hardware is properly selected and
installed.

I never use plug-in UPSes or any other grossly overhyped and
ineffective plug-in protectors. I go online during every
thunderstorm. Never shutdown for such storms. Never unplug
anything. Suffered some direct strikes and never suffered
damage. No damage because the technique is same well proven
methods demonstrated in 1930s research papers.

Those plug-in protectors fundamentally violate those
principles. Summary is provided in "Opinions on Surge
Protectors?" on 7 Jul 2003 in the newsgroup
alt.certification.a-plus or
http://tinyurl.com/l3m9

BTW, plug-in surge protector and plug-in UPS use equivalent
circuits to provide the same ineffective protection. There is
no such thing as blocking or stopping a surge even with a
transformer. Transformer can help to divert the surge. But
again, it still requires the well proven 'whole house'
protection 'system'. Yes - a 'system' that includes the most
critical 'system' component - earth ground.

Plug-in UPS serves one primary function - data protection.
Surge protector is defined by its most critical component -
that plug-in protectors just don't have and forget to
mention. Read that above, previous summary discussion for
details.


Vanguard wrote:
"Ben" wrote in message
If I get one of these UPS surge protectors would that mean I
could use my computer during a thunder storm?
thanks,
Ben


Better to install a whole-home surge protector rather than the
cheapie surge protectors you buy at the store. They cost about
the same (unless you need to have an electrician do the wiring for
the home surge arrestor). Then everything in your house is
protected. however, surge arrestors only protect against surges.
They don't protect against sags. Your power supply would have to
suck more current to offset the loss in voltage until the sag
became too low (your lights and television will work but not the
switching power supply in your PC). Surge protectors also do
little to condition the line (but then some cheapie UPSes are
just pass-through units, too). I prefer to get a UPS that
generates the power output rather than just pass it through. A
UPS with an isolating transformer is even better but then they get
really heavy; mine weighs 60 pounds for the case with transformer
and another 60 pounds for the 2 batteries, for too many other
goodies to list, but then it cost as much as a high end PC). But
even a cheapie UPS is usually better than a surge protector. You
could spend $60 on a good point-of-use surge protector (i.e., you
plug it in the wall install of the point-of-entry whole-home surge
arrestor) and hope that it is still working (since many never tell
you when they've gotten fried) or you spend twice that much on a
low-end UPS that protects better. When the power goes out, the
surge protector doesn't do anything. It can be handy to continue
computing while the power is out. You're television don't work so
sit at your PC. You can check the weather, especially if that
caused the outage. You can contact your power company (since
calling in puts in the queue with everyone else trying to report
the outage). You can even hook up a low-power intensity lamp so
you can see without having to drain the batteries in your
flashlights. I actually have a small UPS left over from a prior
system used to power the cable modem and a flourscent lamp,
and it's small enough to tote around the house to use elsewhere.
Sure beats sitting in a dark house.


If the voltage drops on the input side but you still have the same power
demands on the output side and where you must maintain the same voltage
requirements with the same demand for current, how does the power supply
make up for the deficiency in input voltage?

--
__________________________________________________ __________
** Share with others. Post replies in the newsgroup.
** If present, remove all "-nix" from my email address.
__________________________________________________ __________



  #6  
Old August 30th 03, 04:37 AM
kony
external usenet poster
 
Posts: n/a
Default

On Sat, 30 Aug 2003 01:59:03 GMT, "Vanguard"
wrote:


If the voltage drops on the input side but you still have the same power
demands on the output side and where you must maintain the same voltage
requirements with the same demand for current, how does the power supply
make up for the deficiency in input voltage?


Switching opwer supplies monitor output voltage. They typically
maintain the same switching frequency but as output drops, there will
be increase in the duration of the "on" cycle to keep the voltage up.
So, whether the input changes or the load changes, or both, the
appropriate duration of on-cycle will change, up until the limits of
the heat dissipation (longer on cycle generates more heat) or voltage
drop below minimal allowed, generally due to inadequate sized
transformer per load applied.


Dave
  #7  
Old August 30th 03, 06:45 AM
w_tom
external usenet poster
 
Posts: n/a
Default

Others have summarized your answer. Some numbers. A
switching power supply first ups the 120 VAC to about 300
volts DC (and yes, those 300 volts did hurt). Then it
oscillates that 300 DC voltage through a transformer,
rectifies it, and creates the +5, +3.3, + 12 etc. Notice the
so many transitions. 120 VAC to 300 VDC to various low
voltage AC to regulated 3.3, 5, and 12 DC.

With all those transitions, it becomes easy to take a widely
varying, AC input voltage to create a noise free, galvanically
isolated, robust, and well regulated DC voltage.

Vanguard wrote:
If the voltage drops on the input side but you still have the
same power demands on the output side and where you must maintain
the same voltage requirements with the same demand for current,
how does the power supply make up for the deficiency in input
voltage?

  #8  
Old August 30th 03, 11:20 AM
David LeBrun
external usenet poster
 
Posts: n/a
Default


"Vanguard" wrote in message
.net...
"David LeBrun" wrote in message
e.rogers.com
Greetings
I'm currently restoring a system that was hit with a power surge

where
the following were fried:
PSU
Motherboard
Hard Drive
CDROM
CDRW
Network (PCI)
Audio (PCI)
However the following components from the same system survived:
CPU
RAM (all 3 sticks that were installed)
AGP video
Modem (PCI)
Floppy
Speakers
Monitor
Keyboard/Mouse

I just find it curious that components I thought were sensitive to
voltage like the CPU and RAM would survive while other components
wouldn't. The core on the audio card actually popped (I found the
center of the silicon at the bottom of the case). I keep telling
people to get a UPS or a good surge protector but no one listens

until
they have to pay $$$

Anyone else have a horror story to tell?

Dave.


Sounds like you (or your customers) need to check into using better
power supplies. When not protected by a UPS, mine have simply

popped
the breaker on the backside or blown a fuse (which sometimes

requires me
to open the PSU to replace it) or just tripped on the overvoltage

and
you wait until it resets and the line voltage is okay to power back

on.

By the way, it isn't just surge protectors and, better yet, UPSes

for
which customers never listen. They don't listen regarding backups,
either. When they whine about really needing to get their data

back,
they look like deer in headlights when you ask about their backups.


--
__________________________________________________ __________
** Share with others. Post replies in the newsgroup.
** If present, remove all "-nix" from my email address.
__________________________________________________ __________




I'm not sure how it was connected when the surge happened. I know it
now has an Enermax PSU which I've never had a problem with. I also
know that 2 or 3 other people have worked on the system before it came
to me so no telling how or what caused the problem and what was done
to try to fix it. I opened the case and found remnants of drink
spills, a cpu heatsink with about 5 pounds of dust under a fan whose
bearings are on the way out, wiring nest sitting right in front of the
cpu heatsink, no case fan and the psu vent blocked with another wiring
nest. Anyone that actually knows what they're doing should have fixed
at least one of these problems by force of habit as far as I'm
concerned. First thing (rather second...first I just stood there
shaking my head) was to start cutting a hole in the case for a fan! I
event went as far as lapping the heatsink because I knew heat was
going to be a real problem. Don't know who did the work on it when it
came to me but I know I wouldn't have them work on a system belonging
to my worst enemy! What really bothers me is there are some people
who charge an arm and leg to build/repair systems and what you get is
something that looks like it came out of a meat grinder.
I had installed backup software originally and with the burner
installed there shouldn't have been any problem with the hard drive
failing but like you said...they just never listen.

Dave.
(sorry for the rant)

  #9  
Old August 30th 03, 05:29 PM
w_tom
external usenet poster
 
Posts: n/a
Default

The plug-in UPS serves one primary function. It protects
data from power problems. It does not protect hardware. Did
you read the long list of exemptions attached to that
warranty? Good luck if you need to have that warranty
honored.

I have a UPS right here for 120 volt operation. To generate
(in battery backup mode) what is considered 120 volts, it
outputs two square waves of 200 volts with a 270 volt
transient between those square waves. This output could be
destructive to some appliances such as small electric motors.
However computers are so resilient that even this harsh UPS
output will not harm computers.

The plug-in UPS is for data protection. Computers already
(should) have internal protection which is why many UPSes do
not damage a computer.

David LeBrun wrote:
OK...this is getting a little too technical for me (I am by no means
an electrician) but I guess I understand the basic principles. I do
however find all these details interresting even though some of it is
way over my head.

I do have to agree that there are cheap UPS units and then there's
REALLY CHEAP units. I think that any "consumer" or "retail" UPS is
going to at least be cheap relative to any "industrial strength" unit
which probably means that the units I have are at least cheap. I have
one which (now that I really look at it) looks like nothing more than
a power bar with a battery in it. The other one is a big and heavy
metal box which has more guts in it judging by the soft hum that comes
from it during normal operation and not so soft hum when disconnected
from AC.

All I know is if anything were to happen to my equipment by these
things not doing what was advertised I would just have to cash in on
the warranties offered by the manufacturers and if this casualty
system were mine hooked up to one of my UPS units you can be sure
they'd be footing the bill to get the parts replaced.

Dave.

  #10  
Old August 30th 03, 08:57 PM
Vanguard
external usenet poster
 
Posts: n/a
Default

"kony" wrote in message

On Sat, 30 Aug 2003 01:59:03 GMT, "Vanguard"
wrote:


If the voltage drops on the input side but you still have the same
power demands on the output side and where you must maintain the
same voltage requirements with the same demand for current, how does
the power supply make up for the deficiency in input voltage?


Switching opwer supplies monitor output voltage. They typically
maintain the same switching frequency but as output drops, there will
be increase in the duration of the "on" cycle to keep the voltage up.
So, whether the input changes or the load changes, or both, the
appropriate duration of on-cycle will change, up until the limits of
the heat dissipation (longer on cycle generates more heat) or voltage
drop below minimal allowed, generally due to inadequate sized
transformer per load applied.


Dave


And that means more current is drawn on the input side, right?

--
__________________________________________________ __________
** Share with others. Post replies in the newsgroup.
** If present, remove all "-nix" from my email address.
__________________________________________________ __________



 




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