Information about Surge Suppressors
I think I need a surge suppressor!
So, you’re wondering whether you need a surge suppressor, sometimes referred to as a surge protector. Well, let’s first explain a little bit about what it does, and how it works.
What does a surge suppressor do?
A surge suppressor is usually fitted between the mains power supply and the device(s) requiring protection, typically computer or communications equipment, and it’s principle function is to prevent these devices from being damaged by voltage ‘surges’ which may occur in the supply. These surges (and shorter duration ‘spikes’) are commonly referred to as ‘transients’, which are momentary disturbances in the usually smooth voltage supply. From a domestic point of view, a surge suppressor often resembles the standard type of power extension strip, similar to the surge suppressor pictured at the top right of this page.
When a transient occurs, it can be from a variety of sources. Some possible sources you could consider include lightning, switching on fluorescent lights, motors, welders, power supply faults, etc. The supply into your home is usually very consistent and well controlled. It is known as an AC supply, which stands for ‘Alternating Current’. Within the UK for example, this means that the 230v supply switches from positive (+) to negative (-) and back to positive (+) 50 times each second (meaning 50Hz). You can visualise this in the image top left. But when the transient occurs, the usually uniform and consistent wave form becomes disturbed, also illustrated in the same image. This transient doesn't last long at all, just a matter of microseconds or even nanoseconds, but by then, the transient could well have seriously damaged your device, sometimes permanently.
A surge suppressor can never be guaranteed to 100% protect your device(s), especially from lightning transients, but they are strongly urged for use on products fitted with semiconductors, and in particular, computer, monitors, printers, modems, disk drives, etc. Also, it is recommended that although somewhat inconvenient, all the vulnerable devices are plugged into the one surge suppressor strip, and then that strip is simply unplugged after use.