Ted on Tech: Your AC Outlet is Trying to Kill Your Equipment


Thereís an evil demon lurking behind your wall. Itís hiding in your AC outlets, just waiting to wreak havoc on your expensive PCs and peripherals. Itís called line power, and itís up to no good.

Many of us take our power companyís claim of providing 110 volts AC at the wall outlet as being more or less truthful. Itís notóover time, the voltage at your outlet can vary from 90 volts or less to 140 volts or more. And thatís under normal operating conditions. It doesnít take into account that the power in this country is full of power drop offs, power spikes, and noise on the line that rides along with the expected sine wave of current sweeping from positive to negative and back (the AC stands for alternating current).

Truth be told, even at the best of times, line power at the outlet is pretty lousy. And thatís not really good for your PC, monitor, printer or any other peripheral that depends on line power. In fact, power supply problems are one of the leading causes of PC problems. The output from one of todayís high-quality power supplies is pretty well regulated, but many motherboard and component failures can be traced back to power supply problems, with voltage and current spikes managing to make their way through the power supply. And thatís if the power supply itself doesnít die first.

You may think you have the problem aced with that surge protector you picked up at Best Buy, but you donít. The problem is that the surge protectors you can buy at Best Buy and Walmart serve only one purposeóto stop a large surge of electricity, such as sometimes happens when lightning strikes a power line, from getting through to your PC and peripheralís power supplies.

Typical power line glitches, such as voltage dipping below 90 volts or topping out at over 160 volts, zip right through a surge protector and can damage or kill the power supplies found in many PCs and laser-based printers and MFPs. Faulty or damaged power supplies account for a significant number of equipment failures.

If Not Surge Protection, Then What?

As the quality of power at the wall outlet continues to deteriorate, the need for power protection increases. And that means that you need some form of power conditioning. Simple power conditioners are available from about $90, and most do a really great job of filtering out line noise and limiting power spikes, shutting down the power when thereís a surge that exceeds a preset limit (150 to 160 volts is a good setting). Donít mistake these for an Uninterruptable Power Supply (UPS)óa power conditioner doesnít level out the line voltage, it just prevents catastrophic amounts of power anomalies from making into the power supply. For example, itís not uncommon for line voltage to dip, and then overshoot when it recovers, dropping to 60 volts and then zooming to 160 volts before settling back down at 110-120 volts. Called overshoot, this kind of power roller coaster might not completely fry your power supply, but can cause component damage on the motherboard or controller circuitry.††

One solution is a power conditioner. There are a number of good units on the market. The one I have the most experience with is the Next Gen PCS from Electronic Systems Protection. Theyíre not inexpensive, costing between $170-$200, but worth it if you live in an area with poor power, and it provides data logging capabilities as well, though many of you wonít have a use for this feature. A power conditioner (not necessarily this expensive) is probably a good choice if you want to protect a laser-based printer or MFPósomething that doesnít need a controlled shut down.

A more likely solution for most of us, and the one I employ, is a high-end UPS with power conditioning capabilities. I actually have three of these. I have two APCC rack mount UPS units, one 1,500 watts the other 2,000 watts, mounted in the server rack in the basement. Iíve had these for years, and while the batteries need to be replaced every two or three years, theyíve provided good service and protection over the years for the five servers downstairs.

On my production machine, which is where I do most of my mission-critical work, Iíve have a 1,500 watt CyberPower Systems CP1500PFCLCD mini-tower. This model provides excellent power conditioning, a clean sine-wave power output (some UPS devices put out power with a rough waveform that can put a strain on a PC or peripheralís power supply), and can provide a run time of between two and 11 minutes, depending on the load my PC and display is putting on it at the moment. It has a multi-function LCD display that shows various data such as line voltage, output voltage (116 volts at the moment) and battery charge. This model sells online for around $200, and after a year, Iím very pleased with the way itís performed through several power outages and brownouts. When the time comes to replace my rack mount units, the APCC UPS models are likely to be replaced with ones from CyberPower.

Whether you go the power conditioning route, or more likely, with a power conditioning UPS, keep in mind that itís very likely that your AC power is way more problematic than you think, and that $200 or so for a high-quality UPS with power conditioning features is inexpensive insurance for mission critical data. Consider it just as necessary as good backup plan.

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