Cherryland Electric Cooperative brings you basic information on surge protection and how you can protect your home or office from damaging power surges.

TRANSIENT VOLTAGE SURGES

Our power needs are fairly basic, lighting, heating, and power for electric motors, that's why the founders of modern day electric utility companies and the power distribution system decided to utilize alternating current instead of direct current. They set the stage for a series of electrical and electronic phenomena called TVS, Transient Voltage Surges. Our lighting requirements were satisfied through the use of incandescent bulbs, and later fluorescent tubes. Electrical heating was supplied by the use of resistive heat radiant devices, and motors were controlled by resistive devices.

Earlier generations of entertainment equipment ranging from crystal radio sets, with vacuum tubes to transistor radios and television sets were more tolerant of voltage fluctuations than today's equipment. Technology never stands still, every day something new comes along that is better, smaller, and more energy efficient.

Technology, In the field of electronics, raced ahead of all other fields. Beginning with the transistor we have developed, compacted, integrated, and miniaturized to the point where a single integrated circuit chip can store a megabyte (1,000,000 bytes) or more of information.  For example,  a few years ago computer chips had only 2,000 transistors in about 3/8" square. Today's Pentium type chips have over 10,000,000! Spaces between components are so compressed that damaging arcing will occur above 5 to 10 volts. Damage can also result from lightning even miles away. Even more sensitive chips are on the drawing boards.

The computer industry was one of the first to recognize the need for "computer grade" power. Computer manufacturers have used the general disclaimer "customer must supply appropriate power" for a long time. They recognized that certain power fluctuations could affect the operation of their products.  Unprotected power can scramble your data, prematurely wear components, or destroy expensive chips. Some symptoms are: unknown data errors, I/O retries, irregular performance, lost files, high maintenance rates, intermittent system operations, mysterious bugs and unexplained hardware problems.

Transient Voltage Surge Suppression

Transient voltage and surge current (split-second electrical disturbances), come and go sporadically; resulting in catastrophic failure of electronic equipment, degradation of electronic components and software errors. These problems have been documented by various studies and through the direct experience of users of *solid state devices. By directing harmful power disturbances safely through a bypass path of least resistance to ground, Transient Voltage Surge Suppressors (TVSS) have proven to provide protection from these daily assaults.

The studies and standards defining transient voltage surges have been available for many years. Yet today, many people view the existence of transients and their harmful effect with skepticism. This is due to a lack of complete understanding of the available information on the cause and effect of transient voltage surges and methods to fully protect against them.

In reality, as much as 80% of today's electrical problems can be traced to the activities of such harmless devices as elevators, air conditioners, vending machines, copiers, and large computers. In fact, even something as simple as turning lights on and off will cause surges of power and transient voltages.

The utility distribution system interconnects many different types of power loads that are difficult to control.  In an effort to control the various loads, the utility relies on load switching. Feeder and capacitor switching combined with momentary short circuits and contact re-closures have become a hazard for *solid state devices.

A frequent power disturbance seen in building wiring systems today is transient voltage associated with inductive loads. These disturbances are a result of turning inductive electrical equipment on and off in the vicinity of a sensitive device. Such inductive electrical loads could be in the same facility as the affected device or in another facility close by. The transient voltages generated by these switching operations, from air conditioners to a electric motor, depends on the current supply and current draw of the load. Example: an air conditioner generates a surge voltage as it changes state (turning on/off). So does a 200 h.p. motor; however, the motor generates greater transient voltage due to larger inductance. The resultant transient voltage surge can migrate through the electrical system to solid state devices causing damage.

ELN is defined as electromagnetic energy present in a circuit, other than the desired signal and it's harmonic components. Electrical Line Noise can cause malfunctions in the solid state devices.

Lightning has the capability to generate extremely large surge currents and surge voltage. At the point of discharge of a lightning stroke, 600 million volts and 300-500 thousand amps can be generated. A direct lightning strike is not necessary to cause system damage. Through magnetic induction a lightning discharge two miles from exposed overhead electrical lines can produce a 20 KV surge resulting in potential catastrophic failure of electronic equipment.

What to Look For In Surge Protection

400 vs 330 Volt Clamping. Most cheap devices will not offer specifications better than UL's 400 volt clamp rating. This means spikes will rise to 400 volt levels before they are contained. If this is from the bottom of the sine wave, the un contained spike may actually rise to nearly 570 volts! Your equipment will be damaged every time the photocopier fires off a copy; or transients jolt from air conditioners, elevators or large switching motors, etc.

Sine Wave Tracking. Cheap devices do not have sine wave tracking. Its is a high- tech capability that clamps spikes tightly against the sine wave. This prevents spikes from rising too high. High rising spikes are killers.

 Response Time. Cheap devices have a 5 nanosecond response time, sometimes even slower. Too slow to be effective. Response time less than 1 nanosecond ( a billionth of a second) is much more acceptable.

Safety Diagnostics. Devices with two LED diagnostic lights warn you of four critical safety features: (1) the power is on; (2) the protection is present (It's working even if the power is turned off); (3) the wiring configuration inside the receptacle is correct (with the conducting hot wire on the correct side, otherwise you could get a severe shock by touching two appliances at the same time); (4) sufficient ground path to which damaging spikes can be directed (cheap devices may never tell you until a fatal moment. No ground path, no protection.)

Warranties. Most hardware store devices have NO warranty or only one year warranty. If they have an equipment damage coverage, are you going to get any satisfaction from Korea, Taiwan or somewhere in China? A quality device provides you a lifetime warranty with coverage of any damage from $2,500 to $25,000!

Let-Through Voltage. This is rarely mentioned in cheap devices but is very important. For example, a quality protector under conditions of 6,000 volts 200 amps only allows 10 volts through. Lesser devices don't even come close to offering this level of protection.

Joule Rating. This is a measure of how much damaging energy suppressors can handle. The higher the better. Many don't mention this, or they range from 50 to 200 joule level. These low ratings mean that their devices are not made to handle serious power disturbances like lightning. (But, they look nice!)

Peak Amps. A similar energy absorbing rating is called "peak surge current," measured in amps, the force behind the voltage (more accurate than joule ratings).

Telephone Line Protection. If you are attached by a modem to the outside world, on the internet for example, you need this feature. Telephone lines are antenna systems that direct powerful surges right into the heart of your computer, and to anyone attached to yours, even if the lightning activity is miles away.

Noise Attenuation. Electro-Magnetic Interference (EMI) and Radio Frequency Interference (RFI) are disruptions on the smooth AC power line sine wave. This noise on the power line can be caused by lightning, generators, radio transmitters or even household appliances. This noise shows up as glitches or errors on computer systems, or "snow" on a TV.

Thermal Fuses. Few cheap devices have "thermal fuses" in them. They omit them because it increases the cost. (This is a quality feature.) These fuses are safety devices that are activated in the event that there is an extended over voltage (which can happen). They will automatically take the device off the power line, eliminating the possibility of a burned protector or damaged equipment.

Frequently Asked Questions