Despite popular belief, a power surge is not always a massive electrical surge due to a lightning strike, storm or a major power fluctuation. Power surges occur many times every day and are mostly very mild and very brief, usually only lasting nano-seconds.
The problem is that over time, all these little ‘attacks’ on your expensive electrical appliances add up, until one day they begin to malfunction or fail altogether.
Power surges can also damage light switches, power outlets and large electrical appliances such as fridges, washers and air conditioners. Without surge protection, the lifespan of practically everything you own is being gradually eroded.
Because of the general misconception about power surges, many people still don’t have surge protection in their homes. Although they’ve spent thousands on home theatre systems, wide screen tv’s and computers, they won’t spend a few dollars protecting that equipment.
Electrical experts recommend that we have a two levels of protection:
- A surge protector in the meter box, protecting the general household wiring from incoming surges on the mains line
- Individual surge protectors between each of our major appliances and the power points they plug into.
This way, by the time a surge reaches your appliances, it has hopefully either been weakened or diverted to ground by the combined action of both surge protectors.
Types of surge protectors
While they achieve similar results, surge protectors work in several different ways:
- Metal oxide varistor (MOV) is the most common type of surge protection used to divert surges to the earth wire. A MOV degrades each time and will not last long, sometimes only one use.
- Gas discharge arrestor, where the gas only becomes conductive during surges and then diverts them to ground.
- Silicon avalanche diode (SAD) to divert the surge to ground. SADs provide less protection than MOVs, but they doesn’t degrade with each use, so they last much longer.
Some more expensive surge protectors can contain a combination of all three of these systems and may contain a fuse as well.
Choosing the right type of surge protection will depend on your budget and the cost of the equipment you are protecting. For assistance in choosing the right protection for your home, contact your electrician.