Learning Center

Power Protection

For a lot of folks, power protection means plugging everything into an inexpensive power strip with a circuit breaker. While that can be adequate for some electronic devices, general purpose power strips may not fully protect sensitive audio/video components from damaging power spikes. And they seldom filter out the everyday electronic interference from your home’s circuitry, phone line, and cable connections that can affect your system’s performance.

Power protection components come with a variety of options to meet the specialized needs of various systems. In this article, we’ll explain those options. We’ve also put together a simple list to help you make sure the power protector you’re considering has the right features for your system’s needs.

Why do I need power protection, anyway?

You probably know someone who has lost a TV or computer to a power surge during a thunderstorm. Preventing that kind of damage is a big part of what power protection does. After all, unplugging your TV during a storm may not be enough; if your cable box or satellite receivers remain connected, you’ve left a “back door” open for that lightning strike.

Less dramatic — though more pervasive — is the damage done to audio/video systems by minor fluctuations in power, sometimes called “brown outs.” Electromagnetic interference and radio frequency interference generated either by other devices in the home (like vacuum cleaners and blenders) or sources outside it (like nearby power lines or radio towers) can also impair your system’s performance.

Inexpensive power strips seldom offer that level of protection. They normally just break the connection if too much power comes through the line. And even there, cheap strips can fall down on the job. Because general purpose power strips have higher tolerances than expensive audio/video equipment, a surge that could damage your components could pass through the strip and still be under the voltage required to trip the circuit breaker.

To select the right power protection unit, you should consider the components it will be connected to — both now and in the foreseeable future. This can help you select a unit that provides an appropriate level of protection for your system.

Surge protection

Lightning strikes or power company overloads can create surges that could fry your gear in less than a second. If all your audio/video gear is plugged into a surge protector with AC outlets, you might think your system is protected. But these power spikes can also come into your home through your phone line, your cable TV line, and your satellite signal line. You’ll want to make sure the power protection device you choose can accommodate all of the lines that connect to your system.

Surge protectors sacrifice themselves to save your equipment. They’re designed to be the weakest link in the chain from the power source to your equipment, and include circuit breakers or fuses that immediately sever the connection when a large electrical spike hits.

Many surge protectors can also sense if your home’s wiring is properly grounded, and will alert you if a fault is detected. Improper grounding is often the source for audible low-level hums in your speakers.

Better quality surge protectors usually carry warranties that cover damage to connected equipment if they fail to contain a power spike.

Line conditioning

Electromagnetic and radio frequency interference (EMI and RFI) won’t fry your A/V gear, but they can hinder its performance. Devices with digital inputs and outputs, such as DVD players, receivers and LCD TVs, seem especially susceptible to “dirty power.”

  • EMI is caused by an electromagnetic field generated close to your system. Sometimes it can be contained in the current that comes into your home. A washing machine, vacuum cleaner, or blender can add a loud buzzing or a low hum to your audio system. EMI can also affect the quality of your TV picture in the form of “snow” or overall reduced clarity.
  • RFI results from radio waves that can be generated by radiostations, microwaves, cell phones, lawn mowers, and many other sources. These interference patterns often originate a great distance from your home, and can be heard as clicks and pops. Your home’s electrical circuitry can act as a crude antenna, sending RF signals through your system’s power cords and into your gear. Sometimes cell phone conversations or nearby radio transmissions can actually be heard through your system’s speakers. RFI can also cause “snow” in your TV’s picture, dulling image details and washing out contrast.

A power protection component with line conditioning can remove most of this interference, allowing your system to perform at its full potential.

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