TechLine

What you should know before the next time the power goes out
The Scoop on home generators                    

[DEC. 16, 2006]  I know it’s too late for a warning to coincide with the last storm that caused power to fail in Logan County. However, it is not too soon to provide some important guidance before the next storm.   

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You all remember the icing that caused tree limbs and power lines to grow too heavy and fall to the ground just two weeks ago. Power poles snapped, and the result was loss of electric power for some 500,000 Ameren customers in two states, not to mention the countless other households with other power providers that endured the cold without power for up to 7 days. It was only a week ago that some customers had their power restored.

Loss of household power is more than an inconvenience. You can’t ask the 17 people who reportedly lost their lives because of recent power loss. Our lives are now constructed around the availability of electric power, and when it goes out we seem to be helpless.

More and more this sense of helplessness sends citizens out to their local hardware stores to purchase electric generators. Available for as little as $299, the sales pitch says that you can restore power to all your essential household systems. Just add gasoline and pull the handle. Many homeowners will ignore a lot of noise if they can just get the lights and heat back on, and maybe watch an episode of House or ER. Face it, home just isn’t home without electricity.

Here’s the rub: most of those inexpensive generators are ruining the appliances and electronic items that you plug in to them!

Most inexpensive generators put out filthy alternating current, causing the appliances and electronic items to heat up. Clean current, the kind you get from the power company, is measured in terms of stable harmonics, represented by a sine wave.   The alternating poles of current switch back and forth smoothly, in perfect 60 hertz frequency. Ameren states that their power is within 5% harmonics under load. All your appliances and electronic items were designed and manufactured to expect that kind of power.

Most inexpensive generators put out square wave power rather than sine wave power. The ragged edges on the square wave power makes electronic devices react as if direct current was being applied rather than alternating current. The result is that the items plugged into square wave power heat up, and are usually damaged even if only plugged in a short time on a square-wave electric generator.

Many homeowners tried putting all their household electronics and appliances on their new little generators, and many experienced plasma TVs that smoked, furnaces that popped and computers that fizzled. Appliances suffer from shortened lives and loss of features because of this rough, filthy, square wave power.

It would be best that if you’re going to invest in buying a generator for the next power outage, consider the advice of David Blankenship of Blankenship Electric in Atlanta, Illinois:

• • A generator that puts out sine wave power generally costs 30-50% more than square wave generators. Don’t shop price, shop quality.
  • Look at the manual for the generator before you buy it. If it shows square wave output, don’t buy it.
  • Some generators say that they put out sine wave power at 5% harmonics, but they may not put out that quality of power under load. Check the specifications to make sure that the generator you are considering puts out sine wave 5% harmonic power under load.
  • Just because a generator says it will power your whole household during a power outage does not mean that it will power it with healthy power. Many popular brand names will put out square wave power and destroy your expensive belongings.
  • Your insurance company may not pay for appliances or electronics that are damaged by your generator.

The next power-killing storm may happen at the end of this current heat wave, or may not happen for years to come, we might hope. It is never too early to be prepared to make good decisions for our households.

[Jim Youngquist]