I have a computer that connected to an automatic voltage regulator and an a surge arrester. The power supply unit is set to automatic power recovery so that when there's an outage, it will start the machine when the power goes back on. I have surge arrester installed so that when there is a power back on after the outage, it will protect it from the voltage spike and its induction. Also the voltage regulator protects it from the voltage instability during normal operation.
The question is: is this kind of setup enough to protect the power supply unit from the surge of the outage? I don't use UPS since I figure it out, the machine doesn't do any kind of writing to the hard drive.