Electrical Storms

11 August 2009

Q. We have been advised by our hardware support person to switch off the computers in the practice during lightning/thunder storms. Is this really necessary? What are the risks?

A. Apart from installing a lightning rod, it is not possible to protect against direct lightning strikes on a building. Therefore, the people, the computers and the structure of the building are at risk. More often, lightning will strike nearby and a surge will come through the electrical system or phone wires. It is this surge that commonly damages computer equipment. True electrical surges, where the voltage rarely exceeds 25,000 volts, are much simpler to protect against than lightning, where the voltage can reach 50,000,000 volts. An unprotected computer that experiences a power surge will typically have its network card, video card and motherboard fried. If you are lucky the hard drive will be spared. Even if the hardware is not damaged, a sudden server crash due to an electrical surge can lead to corruption of your practice database and cause you all kinds of problems with data loss and corrupted data. Over the last few years, I have lost a dial up modem and an ISDN box to lighting, and many people relate similar stories. Here is how to protect your computers and network: