The surge suppressor (or surge protector as it’s sometimes called) is a device inserted in the utility line (alternating current) and/or telephone to prevent faults from damaging electronic equipment. In reality, a surge suppressor is a transient suppressor. In this unit, three-wire cords connect to an outlet, a power switch, and several utility outlets.
In addition to preventing the peak AC voltage from exceeding a certain threshold, a surge suppressor also saves electronic devices from being spiked. This is accomplished with semiconductor devices. If the power line exceeds the threshold, the power line is effectively shorted to the electrical ground, but the normal flow of current is not affected. An AC power connection with three wires is required to operate the suppressor. When used with two-wire outlets or extension cords, “cheater” adapters render surge suppressors ineffective, because they degrade the electrical ground connection.
With all semiconductor-based electronic and computer hardware, including peripherals such as printers, monitors, external disk drives, and modems, surge suppressors should be used as a matter of habit. It should not be expected that a suppressor will provide protection against lightning-induced transients. Even though it is inconvenient, the safest procedure is to make sure all susceptible hardware is plugged into the suppressor box, and to unplug the suppressor’s main power cord when you are not using it if you are in a thunderstorm-prone area.
Surge suppressors, as their name indicates, suppress and regulate voltage and keep output constant during spikes and surges. In contrast, a surge protector only detects the surge and turns off the unit. You can use a suppressor on devices like computers to avoid turning them on and off over and over again.
The life of a surge protector is not endless. According to most estimates, surge protectors last between three and five years. You might find that replacing your surge protectors every two years is necessary if your home is frequently subject to brownouts or blackouts.
Surge protectors stop surges before they reach the equipment. Surge protectors prevent surges from reaching the equipment and consequently causing damage or trips of the main breakers.