Whole-house Surge Suppressors
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.
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 co-op’s generators. Surges are usually caused by lightning or when electrical equipment, often large motors in nearby commercial businesses, switches off.
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.
A combination of a high-quality whole-house surge suppressor and small plug-in units (on sensitive electronics) provides the best protection. For your large appliances, you should install a whole-house unit. It uses practically no electricity itself.
Contact your local electric cooperative for information, advice, and availability of whole-house surge suppressor systems.
Several companies include a free $10,000-damage warranty when you buy their whole-house units. If any of your major electric appliances are damaged by voltage surges, they will repair them for free up to a $10,000 maximum.
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 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 models available. You cannot judge its quality and level of protection by just looking at it or weighing it.
The key factors to consider are the strength of the surge current that it can dissipate without burning out itself, how fast it reacts, and the clamping voltage at which it begins to block the surge.
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. The input and output telephone and TV cable jacks are built into the unit.
