Surge protection is a technology which is obviously difficult to grasp and the sales people do not make it easier.
Wendell H. Laidley wrote a nice paper to explain it in an interesting way: He shows the 11 Myths of Surge Protection:
- Any surge protection is better than no surge protection
- A UPS will provide dependable surge protection
- Transformers are the best surge protectors
- Voltage-regulating transformers are helpful with computers
- Common mode surges cause computer problems
- Computer modem damage is caused by surge on the phone line
- Signal ground is isolated from chassis ground
- The only risk from the power line is hardware damage
- Surge protectors are permanent devices
- Nothing can stop lightning
- You get what you pay for
All those myths! It makes a very interesting reading, indeed.