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Protect Your Mac


It's not just the name of a soft drink; it's a real danger to your computer equipment.

Electricity, the very thing that powers your computer, can also destroy it. A power surge, a spike, a noisy circuit, a brown out, a power failure - any of these can damage your motherboard, corrupt your data, or otherwise damage you Mac and its peripherals.

The Easy Stuff

If you don't already have your computer and everything attached to it protected with a high quality surge protector, buy one after you read this article. A single lightning strike in the neighborhood or a car knocking down a power pole and causing a short can take out your equipment faster than you can blink.

A good surge protector is the minimum protection you want. It should filter noise (look for EMI and RFI filtering), surges (brief voltage increases), and spikes (instantaneous voltage increases). If you have a modem or are on a network, it should also provide line protection for your phone or network cabling.

Everything connected to the computer should be protected - otherwise a massive spike can move between peripherals over network, SCSI, phone, or printer cables and damage otherwise protected hardware.

You don't want that to happen.

Some newer designs, such as the APC Network Surge Station, not only provide protection and plenty of outlets, but are also designed to handle power bricks (AC to DC transformers used by PowerBooks, many printers, several modems, and some other peripherals) without blocking other outlets.

Clever, very clever.

(And don't forget, your TV and stereo should also be protected.)

Remember, a basic power strip, even one with EMI and RFI filtering, provides no surge protection. Be sure to check for surge and spike protection. And the best even offer guaranteed protection against surge damage, sometimes up to $25,000.

A very close lightning strike can get through almost any surge protector. The insured surge strip or UPS is a great idea.

Incoming Power

Be sure your power is coming from a properly wired grounded outlet. Again, the better surge protectors (e.g., APC) check for faulty wiring. If your wiring is faulty, you'll get power but not have full protection.

Contact a qualified electrician if your wiring needs to be upgraded.

Beyond Surges

Good surge protection is a start, but it does nothing for summer brownouts or for power outages. To address this problem, you want an uninteruptible power supply or UPS.

A properly chosen UPS will give you several minutes to finish your task, save your work, and properly shut down your equipment. Some more expensive ones even have software that let the UPS shut down your computer after reserve power reaches a certain level.

The first rule of the UPS: you can never have too much standy power. When in doubt, buy more capacity, never less. After all, you may add another peripheral to your system.

There are several types of power supplies, but the two important categories are plain and protected. A plain UPS just provides power, but no surge protection. You'd need to buy a surge protector and place it between the wall outlet and the UPS. (I've seen one case where a plain UPS came in for service - a lightning strike had completely obliterated the battery.)

Better power supplies offer the same filtering and protection as the surge protectors discussed above. And some (e.g., APC) also let you know if you're plugged into a properly wired outlet. (I've been a big fan of APC and an APC user for ten years. There are many good UPS companies on the market, but APC has a great reputation and an extensive product line. Recommended.)

How Much Power?

Just how much power do you need? Most hardware is rated in watts, while the UPS is generally rated in VA (volt amps). To convert watts to VA, multiply by 1.4. This is the minimum you need, providing about five minutes of reserve power.

Ideally, you'll choose a UPS with a higher power reserve, perhaps offering 10 minutes or more before you need to shut down your computer. I suggest you get at least one-third more VA than the minimum your system requires. This will provide an additional 3-5 minutes.

Of course, if you can afford a bigger UPS, go for it. Doubling the minimum required VA for your system doesn't just double runtime, it can quadruple it, providing about 20 minutes before you need to shut things down.

Some computer equipment is nicely marked in amps, which makes calculation easy. Just multiply voltage (typically 120 in the U.S. and Canada) by amps to get VA. But wattage ratings are more common - and sometimes hard to find.

I've done some research on Macintosh models, monitors, printers, and peripherals, but the list is far from exhaustive. Still, it's easier than scrounging for owner's manuals.

Macintosh Computers | Monitors | Peripherals | Printers

Remember that not all items need to be powered when the lights go off. If you don't mind resending a print job, either don't attach your printer to the UPS or turn it off when the power goes out. Same goes for modems and sometimes even monitors (especially on servers). But be sure anything not powered by the UPS is protected by a surge strip on the same circuite - otherwise a surge could come over any wire connecting your components. (APC now has UPS models with surge protected outlets that do no connect to the backup battery. Great idea!)


  • Mystery crashes solved, Marc Zeedar, Less Tangible, Mac Opinion, 2001.04.25. "Odd that power problems never occurred to me as the reason for the crashes - I just assumed the ancient PowerMac was behaving irascibly...."

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