There is an article on Yahoo! Tech talking about how to protect your computer from getting zapped. One solution suggested was to use surge protectors.
But what are these surge protectors? What do they do and how? Why is it important? I use a $10 surge protector at home. What am I guaranteed? What am I not guaranteed? What is its difference from a $50 and above surge protector?
I believe there are many people out there who use surge protectors without knowing how they function. (Like me :p) This is actually a serious issue, because we can get lulled into the impression that we are protecting our equipments when in fact, we are not.
*A little digging on the Internet*
1. HP says 63% of electrical casualties are caused by power problems.
2. PCGuide indicates that 45% of computer data loss is caused by power failures and surges.
3. Modern electronics are more sensitive to power fluctuations due to smaller and more delicate components.
4. Surge protectors use metal oxide varistor (MOV) to divert and absorb excessive power.
5. MOVs become vulnerable after absorbing large amounts of energy.
6. Degraded MOVs can potentially cause fire hazards.
Common surge protectors that are available in the marketplace (in stores such as Best Buy, Circuit City, Wal-mart etc.) are Transient Voltage Surge Suppression (TVSS) devices, using metal oxide varistors (MOV) to divert and absorb extra energy during surges and spikes.
A decent surge protector should at least be tested and licensed under the UL1449, the Standard for Transient Voltage Surge Suppressors. Below are 3 ratings that one should note when choosing a surge protector:
Suppressed voltage rating (volts) or clamping voltage indicates the minimum voltage that will cause the MOVs to kick in. Lower clamping voltage means higher protection. Generally, a clamping voltage of more than 400V is considered too high.
Energy absorption and dissipation (joules) indicates the amount of energy a surge protector can absorb before failure. Higher rating means higher protection. A decent surge protector should rate between 200 and 400J. Better surge protectors can rate above 600J.
Response time (seconds) indicates the time it takes a surge protector to kick in during surges. In other words, it tells the time equipments are exposed to high voltage. Smaller rating means higher protection. A good surge protector should respond in less than 1 nanosecond.
It has been a common misconception that surge protectors provide permanent protection. There is, in fact, a limit in the functional capacity of a MOV component. MOVs will wear out after being exposed to a very high voltage surge or sustained small voltage surges. Most of the better surge protectors have lights to indicate if the unit is still functioning. Otherwise, it is recommended to change a new unit regularly.
References:
HP: Power Protect Your Computer
PCGuide: Power
How Stuff Works: Surge Protectors
How Stuff Works: How to choose a Surge Protector
UL: Surge Suppressor Safety Tips
Wikipedia: Surge Protector
Wikipedia: Metal Oxide Varistor (MOV)
