[APG Public List] Protecting Genealogical Data From Electrical
Ray Beere Johnson II
raybeere at yahoo.com
Sun Aug 30 14:30:44 MDT 2009
Since there are so many stories on the list about lightning damage, I thought I'd mention a few things anyone who relies on protecting their data needs to know.
Some of these tips assume the worst. Many of you probably know people who have gotten away with taking risks. (I knew a guy who smoked while siphoning gas. Several times.) That does not mean you will _always_ get away with it. These are offered on the assumption your genealogical data is difficult enough to replace to warrant the best care you can give it.
1: If it is connected to the power lines, there is _NO_ way to guarantee it will be protected. There is very expensive hardware / software that will cut your odds of trouble way down, but even that isn't a guarantee. Insurance is great, but it can't replace lost data. If you have data that is important to you, make sure you have copies that are not connected to anything when there is lightning around. (The people I know who know best not only advise unplugging everything, they advise moving the plug _several feet_ from the wall outlet for full protection. Yes, a high voltage spark can jump that far.)
2: Lightning is the worst (as it injects far higher voltages then you'd otherwise see) but is not the only possible culprit. Work on electrical lines can go wrong, and in rare cases when a car strikes a pole, it can generate a power surge (this happened to my next door neighbours years ago). So surge protectors are good, even if they are no guarantee.
3: If you have a whole house surge protector, ask someone who knows _exactly_ what they're doing (a power-conditioning systems designer* - I've known highly qualified electrical engineers who couldn't be sure on this one) what other protection you can use in conjunction with this. If you use a UPS with surge protection built in, _do not_ connect it to another surge protector. "Chaining" these things sometimes has the opposite effect to what you desire - it _reduces_ your level of protection.
4: If you have any type of "incident" (lights brighten noticeably or fans or motors speed up [a surge in voltage extreme enough to be noticeable, in other words] even if there is _no_ obvious damage, lights dim or power fails with obvious damage to any connected device, a lightning strike / power problem with obvious damage to any connected device, any other device on the same circuit fails and fuses blow or breakers trip even if there is _no_ obvious damage), data protection is presumably the greatest worry for genealogists. You can buy a new computer, but how easily can you replace your data? Hard drives are easily damaged, but they do not always fail immediately. Damage often increases over time. So you need to run diagnostics that will repeatedly check every single sector and cluster on your drive, test the surface integrity, do read/write testing on every one, and if there is any sign of damage, consider that drive finished. At least for any
important use. If there is no sign of damage, still do not trust that drive too far: it was potentially exposed to conditions which might lead it to fail at any time. The only way you could be sure otherwise is if you had voltage monitoring / recording software actively checking the power supplied at the disk at the moment of the "incident".
5: When electrical components, "wall warts" [the black, grey, or white boxes that plug into the wall to supply power to many devices], or power supplies are subjected to a surge in voltage or ampereage, even if they still work there is a chance they have sustained partial damage. If so, one possible - even likely, depending on the characteristics of the incident - result is that voltage output from power supplies or at certain points within an electrical circuit will drop. When voltage drops, the amount of amperes being drawn through that circuit _increases_ (the power requirement remains stable, so at lower voltages the device must draw more amps). A very short drop (when the lights dim, say) is not a problem _if_ there are no other indications of damage. Hidden damage that causes a long term, _internal_ drop in voltage is different. More amps through the circuit means it will heat up more. This will eventually cause it to fail. The failure itself
is not the problem: after all, you're no worse off than you would have been if the damage was so severe the device stopped working to begin with. The problem lies in the fact that sometimes, a circuit will grow so hot it will ignite some of its own components or dust or anything else flammable it is in contact with. Depending on how much flammable material is available, this fire can easily spread beyond the device (many plastics, for example, melt into what amounts to 'liquid fuel'). So keeping an eye on just how hot the internal components of a possibly affected device are getting in the weeks and months that follow is a very important safety precaution. I don't have the statistics on hand to say just how frequently such damage will lead to a fire - but at least in my mind, any increased danger is worth watching out for.
Ray Beere Johnson II
* These guys design systems to protect valuable corporate data centers and the like. Hiring one for even a brief consultation is expensive - but only you can say if the value and amount of equipment you have is enough to justify that. But keep in mind that the only absolutely sure protection for your data, no matter how fancy and expensive a system you put in, is redundancy. Anyone who tells you differently is not worth trusting.
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