1. What's the difference between a surge protector and a fuse?
A fuse is designed to stop sudden large electric currents from damaging the equipment in your house. Sounds the same as a surge protector, doesn't it? But it actually works a different way. Most fuses are very thin pieces of wire designed to allow only so much current through them. The thicker the wire, the more current can flow; so fuses rated for higher currents usually have thicker pieces of wire inside them.

How does a fuse work? If there's too much current (for example, if you've put too many appliances together on one socket), the fuse literally burns out: the wire gets so hot that it melts and interrupts the circuit to protect you. Occasionally, fuses actually "blow": the current flowing through them is so great that they burn out instantly with a loud cracking noise. A fuse, then, is a very drastic form of protection: if anything happens, it shuts off the electricity completely.

A surge protector is designed to smooth out smaller fluctuations in voltage and it doesn't normally shut down the circuit when a problem occurs. You need both fuses and surge protectors for good protection from electrical problems.

The main job of a surge protector system is to protect electronic devices from "surges." So if you're wondering what a surge protector does, the first question is, "What are surges?" And then, "Why do electronics need to be protected from them?"

A power surge, or transient voltage, is an increase in voltage significantly above the designated level in a flow of electricity. In normal household and office wiring in Malaysia, the standard voltage is 240 volts. If the voltage rises above 240 volts, there is a problem, and a surge protector helps to prevent that problem from destroying your computer.

Brief increase in voltage, when the increase lasts three nanoseconds (billionths of a second) or more, it's called a surge. When it only lasts for one or two nanoseconds, it's called aspike.

If the surge or spike is high enough, it can inflict some heavy damage on a machine. The effect is very similar to applying too much water pressure to a hose. If there is too much water pressure, a hose will burst. Approximately the same thing happens when too much electrical pressure runs through a wire -- the wire "bursts." Even if increased voltage doesn't immediately break your machine, it may put extra strain on the components, wearing them down over time.

A spike or surge won't affect other big appliances, but it could harm tiny components in sensitive electronic equipment. What we need is something that smooths out any spike or surge - and that's what surge protectors do.

It's important to note that surge protectors don't give you complete protection. A direct lightning strike is an absolutely massive discharge of electricity; a surge protector probably won't stop such a huge surge from damaging things in your home. Surge protectors are also of limited value when surges last some time and higher than expected currents from the power grid.

A lot of people think that most of the problems come from thunderstorms, when lightning comes through a power line. Although a good hit can certainly ruin your computer's day, but there are other more common sources of surges you need to be aware of. Most of these sources are high powered appliances such as refrigerators, air conditioners, furnaces, even hair dryers and vacuums. Any common household appliance can cause a disruption in the power flow of your house, creating a surge. It may not be as dramatic as lightening, but can cause damage over time.

Therefore, we need surge protectors to keep all the little circuits inside our computers safe from excess voltage peaks. When these power peaks (surges / spikes) occur, it causes the electrical circuit to heat up. Although a big surge can cause the circuit to blow on the spot, lesser surges can peck away at it, eventually causing it to fail.

Sometimes these failures are intermittent, causing your computer to do strange and unexpected things, for example, odd lockups, sudden reboots after it warms up.

Telephone wires can deliver a potent surge into your computer. In fact, phone line surges are more likely to cause damage than power line surges. Why? Your computer's power supply acts as a basic built in surge protector. Even if a surge sneaks through your regular surge protector, the power supply may prevent it from doing any damage. But the power supply is no substitute for the real thing. Computers and electronic devices get damaged on a daily basis due to lack of surge protection.

Apart from the AC socket and telephone line protection, it should also feature an indicator light that tells you when the surge protection circuit is no longer functioning.

Information on surge protection like clamping voltages, response nanoseconds, and joule levels must also be published.

Also, look for "connected equipment" warranty. If the manufacturer is willing to risk money, they're probably selling a good piece of equipment. If it doesn't have a connected equipment warranty, you should wonder why!