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How to Protect Your Computer from Power Problems

Question: I use a surge suppressor and an uninterruptible power supply (battery backup). I live in the southeastern US, and we’re prone to summer thunderstorms. My wife works for the State, and they never unplug their computers. I shut down and unplug everything from the wall socket when we have a close storm. What would your recommendation be? Or is that an unanswerable question unless you’re here?

It may be unanswerable, but I won’t let that stop me from trying.

I certainly can’t give you a blanket “do this or that” answer, as the specifics of the situation really do play a large role in the solution. But I can tell you what I’d look at when I decide how far to take it.

Let me start by describing what I do. My situation is different than yours, but I think the process leading to my solution is a good example of the kinds of things that need to be considered.

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It starts with a UPS

The biggest risk I run is my power suddenly going out due to a downed powerline. Around here, it’s not uncommon in fall and winter windstorms. Power flickering is even more common.

LightningI run one of my computers and some equipment through an uninterruptible power supply (UPS). The UPS provides the bare minimum needed to keep my network, Wi-Fi, and internet connection up, plus one computer. My laptops and mobile devices, by virtue of being battery-powered themselves,  have their own built-in UPS in a sense, and need no additional power-loss protection.

I do this to maximize the time the UPS can keep this equipment running — probably an hour or two. It keeps those laptops and mobile devices usable. All other machines go dark during a power outage. I do ensure that those machines are connected through a surge protector to protect them from power spikes and surges.

It actually starts with a backup

I don’t lose power often — perhaps once a year for an hour or two at most1. When the power goes, it typically goes down “cleanly”, meaning it’s pretty close to turning off a switch.

And yet … one year, a power outage wasn’t so clean. The power went down “roughly” — low and high voltage spiking and dipping before it finally went away completely. I lost one of the hard disks on a machine that wasn’t on my UPS.

Yet I lost no data.

The tradeoff I make is to rely first on my backups. These allow me to recover from many types of failures, including hard disks that fail for any reason. Since I need backups anyway, I choose to rely on them rather than investing in a larger UPS.

As I said, I lost no data; I simply replaced the drive and restored the data from backups.

If my power were more frequently unstable, I might choose a different tradeoff. As it stands, losing a drive to a power hit every few years is less costly overall than a bigger UPS, as long as there’s no data loss.

You might start elsewhere

Being in a lightning-prone area means your risks and the resulting tradeoffs are different than mine. Rather than the power simply going off, your risk might be a direct lightning strike, or even the power suddenly spiking very high prior to going off. Either is likely to do damage.

At a minimum, I’d invest in a good surge protector. I know you said you have one, but I want to be clear it needs to be a good one, not a cheap one such as those I can get away with here. You need one that’s rated to handle the side effects of lightning strikes.

A good surge protector is, in my mind, the 90% solution to your situation.

My personal take is that a UPS may be optional for you. They can be expensive, and you need to trade that off against the risk and frequency of the power going off. Part of the tradeoff also is the risk of data loss, but you can protect yourself as I have, with a sound backup strategy.

Once surges are taken out of the equation, simply losing power while your computer is running isn’t a huge risk. Don’t get me wrong, it is a risk, and not something you want to have happen frequently, but it typically boils down to a data-loss risk as opposed to an equipment-damage risk. Most equipment can handle the power just “going away” without much problem.2

The bigger picture

There’s more at stake than just your computer. For example, you’ll find that your telephone landline3 almost certainly goes through some kind of fuse or surge suppressor already. And of course, we’ve all heard stories of TVs or microwaves being damaged by exceptionally close or direct lightning strikes.

It’s possible that your wife’s office doesn’t need additional protection because they’re already protected at some common source. This is well beyond my expertise, but I theorize that buildings (or segments of buildings) might already be protected with surge suppressors prior to the wall outlet. Some even have battery or generator backup as well.

Of course, it’s also possible they have none of that and a nearby lightning strike will render several electrical devices inoperative.

I hope they have good backups.

It also ends with a backup

Hardware can be replaced. Often, data cannot.

No matter what protection you have in place for your hardware — be it a UPS to protect from power loss or surge suppressors to protect from power spikes and lightning strikes — backups are critical.

If your hardware fails for any reason — even if a minor power glitch causes a disk to suddenly become unreadable — a current backup can save you from catastrophic data loss. In fact, the number of scenarios in which a backup can save you goes well beyond power problems.

Having current and complete backups really is the closest thing to a silver bullet when it comes to computing.

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Footnotes & References

1: And even so, it’s become less frequent and shorter over time.

2: Yes, of course, equipment damage can happen, but the risk is low. The greater risk is to your data.

3: Kids, ask your parents.

23 comments on “How to Protect Your Computer from Power Problems”

  1. Living in the country where all power is over aerial lines tends to make us more prone to lightning. Several years ago I had lightning come in over the power. It literally blew apart one of the 600 amp service lines and blew a hole in the other along with many wall outlets and electronic devices. I thankfully had insurance but wanted more protection. The local power company insisted it was not their issue. I was however able to get them to allow my electrician to place a lightning arrestor between the meter and my main service box. I have had no problems since except for brown-outs which can also kill electronics. The power company has replaced the meter three times though.

  2. Several years back a holy bolt struck the house next door. It popped ALL our breakers, toasted the tv, modem and computer and burned out all the light bulbs in use. A simple $39.95 surge protector isn’t up to that blast of power.
    You’ll have to balance what protection you buy against what you stand to loose in worse-case scenerio.

  3. I live in the deep deep South, and am also subject to afternoon thunderstorms with attendant lightning strikes. My procedure when storms are close by is to save and close all apps, and shutdown via Apple menu, switch off the “surge protector”, and unplug from same. When I leave home I do the same. When I go to bed I do the same.

    It seems to me my computer is as well protected from lightning as I am. However you mention potential data loss as a result of unplugging.

    Does anything described in my above stated procedure increase my risk of data loss, and if so why?

    I understan the necessity of backup, but I see that as a somewhat separate issue.

  4. I want to offer a couple addendums to Leo’s writhing and the comments. Most surge suppressors use MOV’s to do the actual work of controlling the surge. More than 95% of the time when an MOV fails it fails shorted. This means that if you have a suppressor, the last surge it controlled may have failed the MOV and you have no way of knowing it. In a higher lightning area suppressors should be changed routinely.
    Secondly unplugging an item does not necessarily protect it. If the lightning strike is close the EMF from the bolt can produce a large current spike in any nearby coil of wire – like a transformer in a PC. I personally had 3 pieces of stereo equipment destroyed that were unplugged when a bolt hit a tree right next to my house.

  5. So much of the hype is nothing more than scare tactics to sell crap that really doesn’t work. Remember the craze for awhile about the grounded wrist straps so your body static didn’t blow out your entire CPU, RAM, and HD? Those $10 power strips that include a “surge protector” are NOT going to protect against a lightning strike. You’re going to pay a healthy price for a REAL surge protector, and then you have to decide whether you’re prone enough to such strikes to make it worth the cost. Most people are not that prone to begin with.

    Battery backup is even more expensive. It might be a convenience to avoid rebooting in the case of a momentary interruption, it doesn’t really do much good in an extended blackout since the battery will run down. Again, the infrequency and inconvenience really don’t warrant the tremendous cost for someone who just uses his computer to check email, surf the internet, and play some games.

    If money is no object, by all means, spend it on whatever makes you feel comfortable. Those Extended Service Plans they sell in stores when you buy a product are nothing more than a sucker bet, but on rare occasion, they turn out to be good for some individual. It’s also what keeps the state lottery alive. (In case you haven’t guessed, in 25 years I’ve used neither nor needed them. One day I MIGHT be wrong.)

  6. I want to relate a story of what happened to me: A few years ago (I live in Southeast Florida) I lost about $4000 worth of electronics including my oven and refrigerator because of a hurricane, but not how you’d think! Before it hit, a ‘feeder band’ (Small wind surge before the actual storm) caused a powerline in my backyard to short out and send the full 220 volts through my whole house. All of my electronics were on relatively high-end surge protectors (which completely melted inside) and they all burn’t up. Out of a 3-bedroom house, only one microwave, one alarm clock and my stovetop (not even the oven) survived! If a shorting 220 volt line could do this, a lightning strike containing millions of volts certainly can. Definately use a good quality surge protector and battery back-up whenever possible, but in a really bad storm unplug your electronics and don’t forget the phone lines.
    If you get a decent quality surge protector, make that sure you register it with the manufacturer as most of them will replace the value of what’s connected to it if they do fail.

  7. I live in Colorado and have been struck twice, and been close 3 times. I have several external backup drives that I never connect to anything unless I am using them. I keep them away from phone and electrical outlets because lightning will “jump” out of an outlet and fry electronics, even if not physically connected.

    You should invest in a whole house surge protector that is fuse based. I am a home builder and I use a Maxivolt MV100. It will stop a lightning strike that comes in from the power lines. Understand, that it must be placed between the strike entry point and your computer to stop the surge. If your phone or sat/cable lines come in from the opposite side of the home, and the lightning hits after the surge protector (i.e.: SAT dish), it can ride in on the phone/coax lines, which a surge protector can not stop. You can talk to Maxivolt or a local electrician for better incite into your situation, and you will need a licensed electrician to instal this type of unit. Even the house ground type and location can make a difference during a strike.

    Those cheaper surge protectors that Leo discusses, probably are MOV’s, which mean that every time they stop a minor surge, they become less able to stop the next one. They wear out, and the cheaper they are, the fewer surges they will stop, until they are completely useless. How do you know when they are used up, you can’t.

    I too, pull the plug, depending on how high my insurance deductible is and how much time I want to spend buying a new computer. Local electrical codes are designed to keep you alive and in no way guarantee that you will not have damage in the home. Lightning will do anything it darn well pleases, so be prepared.

    Also, the more solar and wind (well known as “dirty power” in the industry) that we add to our power grids, the more unstable the power source will be, as it becomes increasingly difficult for electric companies to supply “clean” power. A surge protector can not protect against the coming brown outs, so get a good battery backup as well, IMHO.

  8. Go to Radio Shack and get an 8 foot copper lightening pole. Drive it into the ground and use grounding wire to attach it to your electric access box, cable access box (antenna), and phone access box (use 3 if more convenient). This will divert the high ‘voltage’ (path of least resistance).
    Most surge protectors shut down when they get too much heat, not volts or amps.
    A whole house surge protector will not stop internal house surges when 2-3 high power devices decide to turn on at the same time (A/C, Fridge, etc.).

  9. I can tell you from personal experience it an APC saved my system.

    Lightening went over my house and struck a tree.
    An earth shattering BOOM and my whole house shook.

    The only problem I had was some messed up settings like my desktop settings etc…

  10. I wouldn’t go to the Shack for rods. I would first check with a local electrician. If your house was built in the last 25 to 35 years or so, you should already be grounded correctly, “if” it was built according to code. Those rods help, but are not as good as a uffer ground (steel rebar into the foundation). You should be able to inspect your ground visually, somewhere near the meter box, making sure you have a good connection, etc. Our local codes do not allow copper rods anymore. They are not good during a strike, as I found out a few years ago.

    If your power is falling off when appliances come on, which should be extremely rare in a newer home, you have either poor wiring (lines too long, too many outlets or electrical items on one circuit, or more than one large appliance on one circuit, or a poor source of electric coming from the power company. Most power companies are regulated by the PUC to keep the power within a certain range or big fines will come down upon them. Hence, my warning about wind and solar. If dirty power is being generated between their generator and your house, which they have little control over, you will still have problems, no matter what the fines. I lost a control board in my furnace and my electric double oven, (yes, they do use computer boards which are as sensitive as your computer mother board and just as big). But, good luck proving it was the Power Company. If you happen to loose your heat, check the 3amp fuse on your furnace mother board, it won’t run without it.

    I agree that a whole house unit will not stop internals, but that is not their purpose.

  11. You allude to it in the article, but protecting your modem may be important as well. Many surge suppressors have a port to run your phone line through. We had a lightning storm last summer that blew out my computer modem, the modem in my TIVO unit, and the credit card readers in all the local businesses.

  12. Both my neighbor and I have at separate times had to replace a motherboard as a result of lightening in the area (not direct hit) arriving via the RJ-45. Since then I have connected to the internet wirelessly through my router. In addition I protect the power with a UPS, although we have not had much of a problem with power.

  13. Lightning is a constant problem here with computers. When there is a lightning storm,I turn off my computers (they have surge protectors) but mainly, I unplug the phone line to my modem. I lost a modem because of lightning once, and the phone line isnt protected. I would suggest unplugging the phone line to a computer during a lightning storm.

  14. @Chris: a good UPS can protect against brown-outs. APC uses the terms boost and trim to refer to boosting levels in a brown-out and trimming back levels that are a bit high but nowhere near a surge.

    Also, a good UPS can indeed protect phone lines and coax. Also, Ethernet – I own quite a few that provide Ethernet protection. There are *lots* of models available.

  15. My husband is a long-time electrician; we lost two dial-up modems to lightning but it didn’t ruin the computer, as we are on a hill, and our part of Michigan has a low of power failures, and a brown out can burn out ALL your appliances with motors. We unplug our computers for COMPLETE protection.

  16. In my job as a broadcasting engineer I have seen lighting damage on numerous occasions, but only once was it due to a direct lightning hit on a power line. If lighting strikes within 10 to 20 yards it can induce a massive electrical surges in to power lines, phone lines and TV cable lines that will destroy electronic equipment. Fiber lines are the only ones that are immune to lightning. As a rule, during the summer lightning season we always unplug our computers if lightning is in the area, or if we are going away for the weekend. Although surge protectors are reasonable protection from power company induced problems, a close lighting strike can be so massive that consumer surge protectors can fail to provide adequate protection.

  17. There is NO surge protector made that will protect your equipment from a lightning strike close to the house (power lines or phone/modem lines).
    A close lightning strike will blow your surge protector AND you computer plugged into it.
    If you are in a lightning prone area, BEST protection is shut down AND unplug PC, Modem etc.
    Lightning CANNOT damage devices which are unplugged.

  18. Leo’s advice and all of the comments are right on. In addition, you can also get whole house protectors. In the scheme of things they are not even very expensive. In new contruction you ahould be able to get one for less than $500, although retrofitting is not always possible. Also, many local power companies offer whole house protection. They put a device on your line at the primary entry point. I pay Florida Power and Light $10/ month for this… I still use cheapo wall protectors and Back-up 3-2-1, but Idon’t lose any sleep over this very real problem.

  19. I have a laptop that I charge up many nights and use on battery power during the day. Also, I back-up most of my data to OneDrive and do image backups to an external HD that I store in a safe deposit box. So, how much $$$ is a decent surge supressor? I assume it is at least $300 (please advise). My laptop is great for me and it costs about $650. It would seem at WORST, I could just buy another laptop and restore my data and of course reinstall my software (a royal pain but I think I could restore things in maybe 20 hours). Am I missing something? If I can get a high quality surge supressor for say $50, then that “insurance” would be worthwhile. Thoughts?


    • Sounds reasonable to me. For similar reasons, I never purchase insurance for my electronics. I’ve probably saved the cost of two computers by now. I once spoke to a truck drive who worked for a medium sized shipping company who said the company only gets liability insurance for the trucks. The money saved each year is the cost of two trucks. Those 2 trucks are their insurance.

  20. APC UPS’s come with software called PowerChute which can be connected to your desktop and includes an option to command a desktop shutdown when the battery power goes below so many minutes of power. The program tells you what the current load is and estimated battery life in minutes for that load. This allows a choice of what the UPS should supply and one can, for example, in a multi-monitor setup decide to have the UPS only power a single default monitor rather than all monitors and therefor have a longer time before auto-shutdown.

    This is important since many electrical failures can occur while your system is running BUT unattended.

    If you are in attendance one has a chance to manually stop some desktop operations to reduce power further and extend the shudown time.

  21. Reading this article makes me wonder about UPS battery back-ups: does it matter that the output voltage from it might NOT be a true sine-wave AC signal? …either normally and/or during protection mode. Especially during protection mode the UPS must use the DC voltage of a battery and generate an appropriate AC voltage for output. In worst case the output might be a jagged saw-blade shape between the AC voltage peaks? (I have seen some UPS equipment that touts having true sine-wave output which made me think about all of this.) It would seem to me that equipment using the line voltage to control internal functions might be affected adversely, especially high-frequency functions involved with satellite/cable/antennas and high-quality audio and video equipment, if the sine-wave is not pure. (Actually, there is no guarantee that incoming voltage from the power grid is pure sine-wave to begin with.) Does it really matter?


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