When shopping for a surge protector, there are some things
to consider when narrowing down which one works best.
UL 1449 Clamping Voltage
Underwriters Laboratories (UL) rates the clamping voltage
of surge protectors. The lower the rating, the better the
protection. The lowest UL rating for clamping voltage is 330
volts. UL tests household surge protectors at 500 amps. Other
types, such as whole-house or heavy-duty, industrial models,
have a multitude of differences in their testing program.
When comparing clamping voltages, make sure the rating reflects
500-amp test results.
Surges can occur between hot, neutral and ground lines. Choose
a unit that protects along all three lines.
A breaker stops the flow of electricity when a circuit is
overloaded and is not related to surges or spikes.
Ground Indicator Light
This light shows that the ground path is intact to provide
This rating indicates how fast a surge protector can react.
The faster the better.
This indicator lets you know the unit is protecting. Once the unit has reached its capacity
and is no longer protecting, the light will go out.
Power Shut-Down Protection
This feature shuts off power to all outlets once the unit has reached its capacity
to protect. Power shut-down prevents additional surges and
spikes from reaching connected equipment before the surge
protector is replaced. This assures you that if the unit has
power, it's protecting.
Cable Line Protection
Coaxial cable lines can carry
surges and spikes. For complete protection of your TV / DVD
player, you should protect the cable line as well as the power
line. To protect this equipment, select a surge protector
with coax line protection.
Digital Satellite Line Protection
lines can also carry surges and spikes. These lines, however,
can't be connected to standard coax cable jacks. Choose a
surge protector with specially designed digital satellite
Phone Line Protection
Surges can occur on telephone
lines. Phones, fax machines and modems can be damaged from
surges on the phone lines. To protect this equipment, select
a surge protector with phone line protection.
EMI / RFI
Electromagnetic interference (EMI) and
radio frequency interference (RFI) are types of noise on the
power line that can interfere with equipment performance and
possibly cause memory loss. When comparing EMI / RFI specs,
the wider the frequency range (kilohertz to megahertz) and
the greater the noise reduction in decibels (dB) across that
frequency range, the better the filtering.
A joule is a measurement of energy.
The joule rating on a surge protector indicates the amount
of energy that a device is capable of absorbing. In general,
the higher the joule rating, the better the unit is able to
protect your equipment and the longer it will last. The joule
rating is determined by the total number of metal oxide varistors
(MOVs). An MOV is a component in surge protectors that absorbs
excess electrical energy and clamps the voltage to a safe
An audible alarm lets you know the surge protector
is no longer protecting and should be replaced. This feature
is important when the unit doesn't feature power shut-down
protection or when the indicator light is out of sight.
Check the manufacturer's warranty. A data recovery program is an added bonus that will cover costs related to the task of recovering data on a malfunctioning hard drive as a result of a surge.