The average residence receives more than 2,000 transient electrical surges each year, resulting in approximately $26 billion in yearly losses for North American homes and businesses.

A home's electricity is generated at plants that can be hundreds of miles away. It's sent out at high voltage, and then stepped down by high- and medium-voltage transformers and routed to its final destination. The system, though largely reliable, is still a delicate one. Our modern power infrastructure produces relatively consistent output, but minor variances occur and the process of switching power stations can easily alter output.

These changes in output resonate through the electrical system, spiking nearly instantly and sometimes producing enough heat to melt microchips and ruin expensive equipment. A common cause for surges originating from outside the home is lightning. Even when lightning strikes miles away, it can travel through phone, cable or power lines into the home and cause massive amounts of damage.

Surge defense requires a sturdy response. Installed next to the home's breaker panel, main-service surge protectors provide protection for everything in the house, from the refrigerator to a wide-screen plasma television.

If you stock main-service surge protectors, make sure they are UL1449 listed and carry a protective warranty for equipment connected to it. The surge protectors you stock should provide 60 kA of surge current capacity and create a single point ground for all incoming utilities — something now required by code in many states. Also make sure they're backed by a product warranty and/or a “connected equipment warranty,” which acts as a secondary insurance policy to a homeowner's policy. Let's walk through a home and look at the computer equipment, electronic devices and other home appliances that should be protected against transient electrical surges.

Many modern homes have lots of expensive computers, home entertainment and communication devices dangerously susceptible to transient electrical surges. Televisions and stereos, phones and video game systems all are degraded by these minor surges on a daily basis. Individually the surges may not cause noticeable damage, but over time they weaken the structure within the microchips that power these devices. Ultimately, that $3,000 high-definition television burns out much sooner than you would expect. That damage often occurs after the warranty expires.

In a family room, the first line of defense against these internal transient surges is the standard outlet strip surge protector. Ranging in price from $6 to $60, the old adage “you get what you pay for” generally holds true. These devices typically use small metal-oxide varistors to shunt the event away from sensitive loads. Often the device is only rated for a few hundred hits, and sometimes they do not have varistors in all modes to provide complete protection. As can be expected, more complex surge protectors provide more protection but cost more.

With the typical home office equipped with thousands of dollars of computer equipment, protecting a homeowner's investment in this area is a top priority. Computers are most susceptible to the surges already mentioned, and can be protected by a both a surge strip and a main-service surge protector. However, computers are frequently connected to another source of problems. Electrical surges can also be carried through phone and cable lines into the home. That means broadband cable modems and Web service provided via digital subscriber lines (DSLs) can transfer surges into your computer. Though some strip protectors offer an outlet for phone lines to be connected, since these surges almost always originate from outside the home, a main-service surge protector offers the best protection for all electronics in the home. Many models offer coverage for both phone lines and cable.

Large appliances such as refrigerators, ovens, microwaves and dishwashers are often controlled by powerful but fragile microchips. These same appliances also cause frequent and varying loads on the electrical system, causing low-level transient surges. Transients caused by home appliances usually result from the discharge of stored energy in inductive and capacitive components. Electric motors (such as those powering large central air-conditioning units), can create a continuous stream of 250V to 1,000V transients.

A more elusive transient surge is caused by the switching of inductive loads. A 250V to 3,000V transient surge can occur with the interruption of an inductor's current. These transient surges occur with the opening and closing of contacts for motors or fluorescent lighting using magnetic ballasts.

Unlike smaller devices like computers, washing machines and dryers are hard-wired and cannot be quickly plugged into a simple power strip surge protector. This makes them even more susceptible to surges that originate outside the home.

Your customers should always suggest a two-tier approach to surge protection — installing a device at the breaker panel and then downstream in front of electronic loads is the best defense. A main-service surge protector placed next to the breaker panel will protect a home from external surges, while outlet strip surge protectors for computer and entertainment equipment will offer added protection from internal surges caused by other appliances.

The microprocessor revolution has improved homes more than anyone could have imagined, but with these benefits also comes the responsibility to protect that technology. With a little planning and the proper tools, protection can be guaranteed for every room of a home.

Mike Boyd is marketing manager for the Industrial Surge division of Intermatic, Spring Grove, Ill., a diversified manufacturer of industrial and residential surge protection, controls, weatherproof covers and landscape lighting. He can be reached at (815) 675-7068.

Want to use this article? Click here for options!
© 2007 Penton Media, Inc.