Home & Garden

Take steps to protect electric appliances

Q: I have had a couple of electronic items burn out from lightning during thunderstorms. Other items don’t seem to last as long as they should. Will a whole-house surge suppressor protect them?

A: The strongest high-voltage electrical surge your house wiring will ever experience is from a lightning bolt, but there are many smaller surges which also cause much damage to electrical items. This damage may be instantaneous as with lightning or gradual from smaller surges.

More items in a typical house are at risk from electrical surges than just computers, televisions, etc. Almost every modern electric appliance (clothes washer, dishwasher, range, etc.) is full of electronics which high-voltage electric surges may damage.

A whole-house surge suppressor can protect your electronic items from most surges, but don’t expect it to protect against a direct lightning strike. The amount of energy in one lightning bolt is tremendous, and there is very little which can withstand its surge. The energy from a lightning strike can even jump across a switch turned off and destroy electronics.

The majority of the voltage surges are smaller ones created when an electric motor switches off. These may come from a commercial business nearby or even from your refrigerator or vacuum cleaner motor switching off. They slowly degrade the wire insulation or electronics until they fail.

There are many types of whole-house surge suppressors available for use with residential wiring. They are wired into the electrical system and automatically detect and dissipate a surge before it reaches a high enough level for damage.

One very effective type of surge suppressor mounts under the electric meter. This type has to be installed professionally and is often sold by the utility company because the electric meter is removed during installation.

Another type, which I use in my house, mounts under the circuit breaker box. This is connected to the house wiring by just a couple of wires and will protect the entire circuit. A whole-house surge suppressor built into a circuit breaker to fit breaker panels is also available.

Various surge suppressors provide different levels of surge protection. Most use the same technology of MOV’s (metal oxide varistors) to absorb a voltage surge and slowly dissipate it. A physically larger MOV can handle a larger surge without burning out. If the MOV gets fried, it just becomes ineffective and will not affect your electric power.

The key performance specifications to consider when selecting a whole-house surge suppressor are the maximum surge current in amperes and the total energy dissipation in joules. A higher number for both is better. There often is an LED indicator for whether a surge has burned out the MOV.

Q: I used my fireplace often this winter, but it doesn’t always draw well and the living room gets smoky. I have heard that nailing a 5-inch board across the top of the opening will help it draw.

A: The relationship of the opening width and height dimensions are important for a fireplace to draw well. Many fireplaces are designed with a tall opening more for aesthetics than function and they backdraft like yours.

Reducing the height by 5 inches often helps. Do not use a wood board. Use a steel or aluminum angle. A wood board would be a fire hazard, and your entire house may become one big fireplace.

www.dulley.com.

  Comments