Today's Technology and you

Today's
TECHNOLOGY AND YOU

Want to save money? Spend some on a good surge suppressor!

Q: My answering machine, VCR, microwave, telephones, etc., don't seem to last very long even though I use plug-in voltage surge arresters. Would installing a powerful whole-house surge suppressor help? -Mary G.

A: Today's homes have many devices and appliances that use sensitive solid state components. In addition to the common electronic equipment you mentioned, most new major appliances (refrigerators, dishwashers, clothes dryers, etc.) have electronics that can be damaged by voltage surges.

Although you are not aware of it, there can be hundreds of very short duration 1,000 plus-volt surges in a typical home's wiring every day. The frequency and intensity of the surges depend on your specific location.

Your electric co-op does everything it possibly can to minimize these voltage surges, but it is impossible to eliminate them. The source of the surges is not your utility company's generators.

Surges are usually caused by lightning or when electrical equipment, often large motors in nearby commercial businesses, switches off. They can even be generated inside your own home when your air conditioner compressor stops or you are running your dishwasher or clothes washer.

Although small plug-in surge arresters help, they do not provide the best protection. Even if the voltage surges are not strong enough to destroy the electronic components, frequent smaller surges can slowly break down wiring insulation.

This can cause premature device failure or just faulty operation. Microwave ovens have been known to start on their own. Your computer may get glitchy. Your telephone answering machine may miss messages.

A combination of a high-quality whole-house surge suppressor and small plug-in units (on sensitive electronics) provides the best protection. If you have a computer, VCR or any newer appliances, you should install a whole-house unit. Many electric co-ops sell or lease whole-house surge suppressors. Check with your local co-op for details.

There are three basic styles of whole-house surge suppressors that are commonly used. One design mounts on the circuit breaker box with wires (I use this type in my own home). Another design has the surge suppressor built into a snap-in circuit breaker. The third design, and often the most powerful, mounts directly under the electric meter.

To understand how they work, think of a large "electric sponge". When a voltage surge hits, instead of burning out your equipment, the sponge (usually an MOV material) absorbs the energy. Since the surge is of very short duration, the sponge dries out and is ready for the next surge. A bigger sponge can absorb a bigger surge without being fried itself.

Be thorough when selecting a whole-house surge suppressor. There are significant differences in the level of protection of the many surge suppressor models available. You cannot judge a unit's quality and level of protection by just looking at it or weighing it.

Compare the following specifications. The maximum surge current indicates the surge strength that it can withstand. A higher number is better. A reaction time of one nanosecond or less is adequate. A lower clamping voltage is better because it begins to block the surges while they are still small.

Some of the newest models also provide protection for your telephone and TV cable lines. Many computer and fax machine modems have been destroyed by surges through the telephone lines from a distant lightning strike. Again, check with your electric co-op if you have any questions.

Write for (or instantly download — www.dulley.com) Update Bulletin No. 405 — buyer's guide of the 10 best whole-house and plug-in surge suppressors, designs, reaction times, max. surge, clamping voltage and features. Please include $3.00 and a business-size SASE. Mail to: Jim Dulley, Illinois Country Living, P.O. Box 3787, Springfield, IL 62708.

James Dulley is a mechanical engineer who writes on a wide variety of energy and utility topics. His column appears in a large number of daily newspapers.

18 ILLINOIS COUNTRY LIVING OCTOBER 1999