A nice lady came in the other day with a expensive surge protector she bought from a big box store. She wanted to know why after she spent all that money, does her PC still need a new power supply.

Most people think a surge protector will protect your pc in the event of a storm or lightning strike. That is most certainly false. They probably didn’t lie to you when you bought it, you just didn’t know what you were buying.

A surge is another name for a power spike. It’s when the voltage in the wires exceeds whats it’s supposed to be (115v in U.S. homes) for a short period of time.  Surges happen all day and night in homes. Every time the ac comes on, fridge starts running, or garage door goes up. Those motors put an instant strain on the electrical system every time they start. That can either lower the voltage on the line or cause it to go up depending on other appliances in the home.

Today’s sophisticated electronics require a constant voltage to operate. Whenever the voltage changes, electronics have a hard time regulating the power it needs to operate. That can cause things to break down early or blow up.

A surge protector tries to level out spikes. A good one may even prop up a low voltage condition. If the spike is too much it should send the overage to ground (which is why grounding is important).

Some of the el-cheapo models are only glorified extension cords with a power light. They offer no spike protection at all.

So why didn’t yours work for that lightning strike? A typical power surge is 10-25 volts. A lightning strike could be 50,000- 250,000 volts. There is no way some $20 piece of plastic is going to stop lightning.

They do make systems that protect from lighting strikes, and cost several thousand dollars.