BleepingComputer.com: Better to turn off computer and unplug or not?

properly earthed and all things aside, a direct strike by lightning to a lightning pole nearby could still have the possibility of frying electronics. That being said, chances are that even if there was a surge, old computer plus being left on the vast majority of the time that computer was likely waiting to die anyway, the sudden loss of power or even a slight surge was probably just the final straw. these days, if the house is wired to code, while theres still a chance of a power surge, typically a good surge protector should still be more then enough to protect a PC, especially if its off at the time.

12x48y, on Feb 2 2010, 07:28 AM, said:

Only one of us knows how electricity works. Posting insults demonstrates why you *know* low voltage causes damage. What component is damaged by low voltage? Never listed for one simple reason. You don't know. Those who do not 'know' then post disparaging remarks.

Reality - another poster who knows low voltage cause damage only because he saw lights dim. When challenged to say 'why' low voltage causes damage, he ignored the question; instead posts disparaging remarks as if that proves something. He saw voltage diminish. That proves the damage was from low voltage? Nonsense and classic junk science reasoning.


To be properly earthed, a building must both meet and **exceed** post 1990 code. Many electricians only understand earthing for human safety - to meet code. Fewer and better electricians understand what is necessary for appliance protection - for transistor safety.

Others can learn from this example. Does the breaker box wire go up over the foundation and down to earth? That earthing wire is too long. Sufficient to meet code (for human safety) and too long to exceed code requirements (for transistor safety). One reason for appliance damage: many homes do not have any earthing. Others are not earthed sufficiently for appliance protection. Then when damage occurs, some will automatically and erroneously conclude from hearsay: that low voltage causes damage.

Lighten up Westom. I didn't think that I was insulting, comparing you to Einstein is a compliment, he was brilliant. I'm used to talking to tough guys, So when challenged, I react. Sometime I may appear gruff. If I offended I apologize, I have a weird sense of humor that sometimes gets me in trouble.
Like I said, you do make some valid arguments.

I never said I was an expert at anything, I was simply sharing some past experiences.


One only has to do a quick Google search to see that low voltage, power outages, lightning strikes, can, in theory, cause components to fail. Here ere a few.

"One example of low voltage causing damage would be in the windings of a capacitor start and run motor. During a brown out, the low power can cause the motor to run on the lighter gauge start windings which can burn out more quickly than the heavier gauge run windings".

"the lower voltage causes some motors to turn more slowly than it normally does, and this prevents Counter EMF from building up, and excessive current travels through the motor. This can cause the motor to burn out before its time. "

"Where a thunderstorm or power failure is causing the lights to flicker, where is power is off, then on, again.
Some motors are rated at a certain amount of starts per hour. If you exceed the starts per hour, the motor or other device could develop residual heat"

I think it's well known that even static electricity can damage a computer, so why not a power surge?

Maybe I'm wrong. But, I would still err on the side of caution, and unplug those units which I cared about during thunderstorms, or maybe even if I were to leave the house for a long period of time. If only for peace of mind.

I dont see the need to necessarily unplug it, but shutting it down all the way definitly. and when I leave the house, I always turn off the surge protector. :D

12x48y, on Feb 3 2010, 08:27 AM, said:

Low voltage causes damage to motorized appliance. Therefore AC mains voltage must not drop below 5%. Why are you arguing a straw man? That was not the question. Please read the challenge again.

Quote

Show me a datasheet for any electronics part that is damaged by low voltage? He only assumed low voltage damaged a DVD, Then automatically converted that wild speculation into a fact. A classic example of junk science reasoning. Observation not tempered by fundamental knowledge is somehow a reality? Of course not. Knowledge only from observation is classic junk science.

Why are you quoting irrelevant hearsay? Where did that strawman come from? Show us one fact that says low voltage causes electronics damage.

12x48y used wild speculation to assume low voltage causes electronics damage. He did not have effective surge protection. He assumed that household wiring was sufficient only because an electrician wired the house. His 'observation' is typical of surge damage because he permitted destructive transients inside the house. Effective protection is not obtained by disconnecting or by power strip protectors. Electronics protection is obtained by earthing one 'whole house' protector. Protection is always about where destructive energy dissipates. Either harmlessly outside the building in earth. Or destructively inside a building.

Destructively inside the building explains 12x48y's damage.

Motorized appliances (dishwasher, refrigerator, washing machine, air conditioner) can also be damaged by that surge. Just more reasons why a building earth ground must be upgraded. And why one 'whole house' protector connects short (ie 'less than 10 feet') to single point earth ground. To protect everything for about $1 per protected appliance.

Low voltage does not cause electronics damage.

This post has been edited by westom: 05 February 2010 - 06:01 PM

I've been reading this thread and as much as weston's grammer is a bit off, from the way he speaks, I'd say he might have a BS or AS degree related to this subject, he does make sense.
But I agree that surge protectors are basically just one switch connected to multible outlets. Because that's basically what I use it for, one swith shuts it all off kind of thing.
Ok me personally, I have a Belkin Power Authority 2 Model F5C140. It has been in service since 2001, so far has never had a voltage spike to deal with, it has two lights a red one that says protected and a green one that says grounded, both are lit.
When I shut down my Windows 7 PC.
I go to START------SHUT DOWN and wait till PC powers off via ATX power supply.
Once the PC is shut off, I do not shut off the monitors swith....I shut it off via the COMPUTER button and MONITOR button on the belkin, because I have another pc and monitor running off the AUX 1 and AUX 2 switchs. The Printer switch is off 90% of the time unless I'm using it. So I rarely use the MAIN button.
Since I run SETI@home to crunch numbers via BIONIC I let my computers run 24/7, I only turn off the monitors.

This post has been edited by MrBruce1959: 07 February 2010 - 08:40 AM

This thread is hilarious in a sad, sad way. We have a potential ESL, someone actually answering the question with their own experience, and someone assuming the topic creator is an idiot.

Results are inconclusive about this, but it seems that anytime you interrupt the flow of electrons and things cool down after being so hot, you are causing a bit of thermal damage to the equipment. However, that being said, keeping that computer on all the time also does damage to the earth if you're using coal-generated power.

I wouldn't sweat over it either way. Equipment varies so much and so does experience. I do think you're wise to unplug when things aren't in use-- that little extra effort probably saves you a bundle. I bet your power bill is lower than most and you're using a little less coal.

Whole house protection is a good thing, but it costs a little extra at house creation. Most people aren't even aware of it. I suppose you could install a ground after house creation, but I bet that would cost A LOT. I've never seen a quote for it, though.

This post has been edited by Kazzandra: 07 February 2010 - 03:22 PM

Kazzandra, on Feb 7 2010, 04:12 PM, said:

That ground is required and must already exist to meet the National Electrical code. A homeowner and only the homeowner is responsible for maintaining that ground. And then that ground also is necessary for surge protection. That ground is not optional. It is required for human safety.

Earth ground is completely different from another ground reported by a power strip LED. Disconnect earth ground and that power strip protector will still report ground is OK. Reasons why are obvious by learning about earth ground; that each homeowner is responsible for maintaining.

See http://www.zerosurge.com/HTML/movs.html
All protector components were removed. And lights still reported the protector OK. What lights report is not what you have assumed. If your assumptions were correct, then removed MOVs means that protector light would extinguish. Those lights do not report what you have assumed. Manufacturer is sufficiently and intentionally vague so that you will make those erroneous assumptions.