Lowe's Home Improvement

Surge Protector Buying Guide

All types of surge protectors guard against power surges and spikes, but there are differences. Find out which is the best one for your needs with this guide.

Home Electronics Surge Protector.

How Surge Protectors Work

Surge protectors help protect electronic equipment, including computers, televisions, home theaters, game systems and appliances, from electrical surges and spikes — increases in normal electrical line voltage. Surges carry less voltage than spikes, but can last longer — up to a few seconds. They're often the result a sudden change in demand for electricity, such as appliances or equipment that draw a lot of power — air conditioners, furnaces, refrigerators or laser printers, for example — turning on or off. Spikes are much shorter in duration. They last only fractions of seconds, but can carry thousands of volts. Spikes can result from storms or problems on power lines — such as shorts caused by downed trees or limbs.

Both surges and spikes can damage electronic equipment beyond practical repair — either instantaneously or over time. Even small surges or spikes can eventually destroy or affect the performance of electronic equipment, Surge protectors, also known as surge suppressors, absorb and channel damaging excess voltage away from devices connected to them. However, they have a limited capacity to absorb. Once the capacity is reached, the unit can no longer protect your equipment and should be replaced.

Types of Surge Protectors

Power Strip Surge Protector and Wall-Mount Surge Protector.
  • Power strip surge protectors have a cord that gives you the flexibility to position them close to your equipment. Some have mounting holes that allow you to hang them on a wall. They typically have 6 to 12 power outlets.
  • Wall-mount surge protectors have no cord. They typically have between 2 and 6 outlets. Mobile models are compact and have a plug that folds into the device housing.

There's a difference between a basic power strip or multi-plug adapter and a surge protector. Power strips and adapters offer additional outlet space, but provide no surge protection. You can identify surge protectors by the ratings for joules and voltage protection on the packaging.

Good to Know

You can also find whole-house surge protectors designed to be connected at your electrical service panel.

Connection Types

Surge Protector Connectors.

Surges and spikes aren't limited to electrical lines. They can travel along any wiring. Some surge protectors — such as those designed for home entertainment systems or home offices — have connections that provide protection on other lines. Coaxial (coax), phone cord and Ethernet cable connections allow you to protect devices such as telephones, modems and computer networking devices, as well as cable and satellite equipment. Note that digital satellite lines cannot connect to standard coaxial cable jacks.

Specifications and Available Features

Wall-Mount Surge Protector with Rotating Outlets.

Understanding common specifications and knowing what features to look for can help you choose the best surge protector for your devices:

  • The joule rating indicates the cumulative amount of energy the device is able to absorb before you need to replace it. In general, the higher the rating, the better and longer the device can protect.
  • The UL VPR (Underwriters Laboratories Voltage Protection Rating) indicates the surge protector's clamping voltage — the highest voltage the surge protector allows through before restricting additional voltage. The lower the rating, the better the protection. The lowest UL rating for clamping voltage is 330 volts.
  • Response time indicates how fast a surge protector can react. Lower response times are better.
  • Power filtration is designed to reduce electromagnetic interference (EMI) and radio frequency interference (RFI) — known as noise — on power lines for better sound and picture quality on entertainment equipment. Units with greater noise reduction in decibels (dB) provide better filtering.
  • Models with 3-line protection protect along hot, neutral and ground wires.
  • Auto shut-off protects devices connected to a surge protector by turning off the power to them when a catastrophic surge occurs.
  • A protection indicator light shows the unit is protecting your equipment. If this light is off, it's time to replace the surge protector.
  • An audible alarm also lets you know the surge protector is no longer protecting. This option is particularly useful when the indicator light is not visible.
  • A ground indicator light shows that the surge protector is connected to a properly grounded outlet.
  • Widely spaced outlets allow you to connect plugs with bulky, built-in transformers.
  • Outlet covers block the electrical outlets when they're not in use.
  • Rotating outlets pivot to accommodate large plugs without blocking other outlets.
  • USB (universal serial bus) ports allow you to charge compatible mobile devices.
  • Energy-saving features help you manage electricity consumption. One example is a design that cuts power to selected outlets on the surge protector when a device plugged in a controlling outlet is turned off.
  • A built-in circuit breaker stops the flow of electricity when an electrical circuit is overloaded — when the devices attached to the circuit are drawing more electricity than the circuit can handle. This feature is not related to protecting devices against electrical surges and spikes.

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Good to Know

While many surge protectors alert you when they are no longer protecting connected devices, consider replacing your surge protectors every couple of years to make sure they offer the best protection possible.

Surge Protector Safety

  • Use surge protectors indoors and in dry locations.
  • Don't exceed the electrical rating of the surge protector.
  • Don't use a surge protector with an aquarium or other water-associated products.
  • If the surge protector features a power cord, unwind it before use and don't cover it. Make sure children and pets stay away from the cord.
  • Don't plug a surge protector into an extension cord, power strip or another surge protector.
  • When a using surge protector with devices such as power tools or appliances, make sure it meets the device's amperage requirements and can handle the current the device uses. Read Power Cord Safety Tips.

Follow the surge protector manufacturer's instructions for use and safety.