Mac Musings

Beating the Blackout

Daniel Knight - 2001.01.25 -

I could make all sorts of snide comments about the state-induced energy problems in California, but I'd rather do something constructive. After all, while the current power grid problems and rolling blackouts in California may seem novel to most Americans, in many parts of the world scheduled and unscheduled daily power outages are part of daily life.

When the Lights Go Out

It happens a few times a year at work: the power goes out. There's a collective moan as most of the computers go down, losing whatever unsaved projects were being worked on. If the computer happened to be saving when it happened, files may be damaged.

Sometimes the power comes back up in seconds. Other times it may be hours before current is restored. And when the electricity does start to flow again, it may pack enough jolt to damage equipment.

The first rule of surviving a power outage is turning off the equipment that was running when the power went out. Just hit the power switch on the CPU, monitor, printer, etc. It's easy to turn them back on after power is restored.

Even before that, the cardinal rule is to have everything protected from surges, either with a surge strip or a surge-protecting UPS. Still, better safe than sorry, so turn the equipment off.

Riding Out the Blackout

PowerBook owners can usually ride out a blackout of several hours, at least with recent PowerBooks and well charged batteries.

Desktop computers need not go down with the power; all you need is an adequate UPS (uninterruptible power supply) to keep you running for - well, just how long is up to you. At work we aim for 10-15 minutes of power, which is long enough to know if the power will be right back up or not, and then finish the current task, save, and shut down.

If your equipment is more mission critical, such as an ISP's server farm, you want an hour or two of power plus a power generator to take over during long outages. I don't know much about generators, but do know you can get some whoppingly huge UPSes these days.

You need to look at the potential power draw of your entire setup, especially the computer, monitor, and external drives. It's usually not a big deal to turn off a printer - you can always reprint later - but you don't want to shut down your external hard drive. Here are incomplete lists of power demans for various Macintosh computers and monitors. Our article on surge strips and power protection gives more details on calculating your UPS needs.

Or you can avoid all the calculations with a PowerBook and one or two spare batteries. But until I get my first PowerBook, I'll have my system connected to a nice big 600va UPS - and I'm nowhere near California.