Power surges have been a fact of electricity since it was first delivered to the public. They are inherent in the methods we use to deliver and consume electrical energy. Unfortunately, as technology has become more intricate it has also become increasingly susceptible to damage (sometimes irreparable) from power surges.

The good news is that manufacturers have responded with a myriad of devices designed to protect your sensitive (and often expensive) equipment from the dangers of power surges. This guide offers some general information on the causes and types of power surges and how to protect your equipment.

What is a Power Surge?
A power surge is defined as a brief but sudden increase in line voltage. They can last up to 50 microseconds. Although surges are short (as the name suggests) the excess voltage will exceed the voltage your equipment is designed to handle. Minor surges may not immediately destroy your equipment, but voltage that repeatedly exceeds the proper levels will eventually wear on sensitive electronics.

What causes a power surge?
The most visible and known cause of power surges is an electrical storm, but storms actually account for only a minority of surges. Power can also surge into your home directly from the electric company as an inherent defect in the only method we know to deliver electric energy. Power surges are most commonly caused by electrical appliances in your home, such as refrigerators and furnaces, which frequently turn on and off even when functioning correctly.

What types of surges are there?
There are two main types of surges, internal and external. Internal power surges are caused by appliances or accidents within your home. These are usually minor and are easily protected against. External power surges are cause by everything from lightning to electric company surges that generate outside your home. These are the more destructive, though less frequent, surges that can require a larger investment to protect you.

How to protect yourself from minor surges:

Minor electrical surges will not immediately destroy your appliances, but the frequency of minor surges can cause damage to more sensitive equipment over time. Surge protection power strips are inexpensive and won’t provide protection from larger surges. They are however extremely effective in defending against frequent, minor surges.

The only downfall is that a power strip will shut off the power supply to your devices in the event of a surge. Highly sensitive equipment, like personal computers, are just as easily damaged by frequent breaks in power supply as they are by surges. An uninterruptible power supply (UPS) will provide added protection for your more sensitive equipment in the event of a minor surge.

How to protect yourself from larger surges:

Whole house surge suppressors are available for about $150 and can protect your equipment from much larger surges than a power strip. They also protect everything in your home rather than just the equipment connected to the power strip. They are still not enough to protect you from some of the largest surges dished out by nature and the electric company.

For protection up to about 6,000 to 20,000 volts, you can purchase a whole house surge arrester for around $500. Unfortunately a direct lightning strike generates millions of volts. The only 100% fool proof protection during a storm is to unplug all electronics until the storm has passed.