You and I use electrical and electronic equipment each day. Computers, lights, refrigerators, coffee makers, toasters, microwaves, televisions, the list goes on and on. Most of these devices require 120 volts of alternating electrical current to work correctly and the power companies do their best to provide that to us.
While the power companies do the best they can to give us 120 volts, it is well known that each day there are fluctuations in the voltage as well as random spikes and surges. Voltages vary naturally due to demand. When lots of people run lots of electrical equipment all at the same time, the voltage naturally goes a bit low. The opposite of this is that when most or all the electrical loads are removed, the voltage goes up a bit. Again, the power companies do a good job of regulating all this so that we don't have to worry, right?
Well, yes and no, the engineers who design the electrical and electronic devices we use take some of this natural voltage fluctuation into account. They engineer devices to operate on a range of voltages and they add fuses or circuit breakers to the design to protect the device if the voltage strays too far from 120.
The problems associated with voltage spikes and short duration surges are harder to deal with. These are random, usually happen in less than one one hundred twentieth of a second and can be double or more the average voltage. It is not certain where these spikes come from but some causes include lightning hits that are hundreds of miles away (it is estimated that lighting strikes somewhere on the face of the earth once every two seconds) and turning off and on large electrical motors or other similar magnetic devices.
Most electrical devices and appliances handle these spikes and surges with ease because the spikes are so very quick. Electronic devices like computers and televisions, however, are an exception. The solid state devices that make these devices work are very sensitive to voltage spikes (something about blowing holes in their molecular substrates) and usually fail totally when hit.
What can you do?
- Use a surge protector. A surge protector is designed to absorb spikes and keep the voltage within the proper range. Here are some suggestions to consider when buying a surge protector;
- Look for the UL label that says “transient voltage surge suppressor” or one that meets the criteria for UL 1449.
At the very least, be sure that the surge protector has a circuit breaker or reset button on it. Surge protectors without circuit breakers or reset buttons are known to cause fires and should be avoided.
- Do not place a surge protector near flammable objects and never cover one with flammable items. Surge protectors absorb voltage spikes and covert the energy into heat.
- Understand that the devices in surge protectors damage themselves in the process of absorbing spikes and surges. If the surge protector you are considering does not have an indicator light to tell you if it is protecting your equipment or not, write the date you put the surge protector in service on it and dispose of it after 3 years of use.
- Also, know that after a lightning hit your surge protectors are probably no good. Check all of them and if the indicator light says it is not protecting, get rid of it. (and please don’t give it to someone else to use) If it does not have an indicator light and anything in the same building was damaged by lightning, replace the surge protector.