Get ready for the lightning round!
As we start approaching the summer, thunder and lightning storms become more frequent. Thunderstorms prove to be extremely dangerous for electrical devices, including computers, audio visual equipment, and appliances. In addition, due to the increased electrical demand on the grid due to air conditioner use, brownouts and blackouts are more frequent too.
For equipment that needs to be protected, certainly a solid surge protector is the recommended choice. Quality surge suppressors usually are rated with a joule rating, which defines how much energy the surge protector can absorb in a single event. Good surge protectors usually are rated at 1000 joules or more and are often in the price range of $20 - $30. A cheap $10 power strip does not afford much protection.
For critical computer and network equipment, you should consider an Uninterrupted Power Supply (UPS). A UPS provides solid protection against electrical spikes and is equipped with a powerful battery backup to keep your computer on during brownouts and blackouts.
The most obvious and overwhelming electrical catastrophe is lightning. Lightning does not have to strike in your immediate vicinity to cause devastation to your system. When a lightning strike hits the city's electrical matrix, a crushing jolt of energy is distributed through the grid, resulting in severe electrical spikes and blackouts. This one-two punch to your computer can be caused by lightning strikes miles away.
A good UPS also provides your computer with 15-75 minutes of backup power as well as constant voltage regulation. This is important so that you have time to save that important file you have been working on and shut the computer down gracefully.
Note, if you have a laptop, laptops have built in batteries, so a UPS would not be necessary, just a good surge suppressor.
Jon Allen
9:19 am on Friday, May 18, 2012
While it is certainly true that thunderstorm season brings with it disruptions that can damage circuitry, it is important to be a little clearer about what exactly needs to be protected. While it is true that a laptop has no need for a UPS, it is still true that if it is using a wired connection to the internet, that is another channel through which it can be damaged. This is why if I am using my laptop and a storm comes through, I generally unplug the ethernet cable and work offline and/or shutdown the PC. While it is true that a good surge strip with protected I/O jacks for the ethernet can help, the ethernet circuitry is much harder to safeguard than the power inlet to either a laptop or a desktop. I know this, since I've designed circuitry of these types over 30 years, and have even designed a phone system that can operate without interruption during a NEMP (nuclear electromagnetic pulse) event. It is an expensive system that only the Pentagon and Whitehouse could afford to deploy.
David Cohen
11:14 am on Friday, May 18, 2012
Joe-
Great suggestion, yes, if a storm comes through, unplugging is a good idea.
Dave
Jon Allen
11:36 am on Friday, May 18, 2012
David,
I made that suggestion not just as an experienced electronics designer, but as a resident on the side of Sargent Hill, where I've had a transformer less than 10 yards from my house get a direct strike of lightning, the transient killing even incandescent light bulbs throughout my house (and filaments are more surge tolerant than just about anything). Obviously, this just proves that if it's close enough, a lightning strike will take out anything that's still plugged in (arcs jumped around the light switches, carbonizing the contacts), only a substantial distance of air (preferably with other grounded surfaces at closer proximity) will stop it. Well grounded, metallic switch and junction boxes help, since the arcs will always take the shortest paths.