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Isolation:Your Best Investment - 1/6

Isolation: Your Best Investment For Reliability - 59059 Isolation: Your Best Investment and Strongest Investment

In 1999 the Science department at NASA conducted a study on lightning, ground voltage, and structural impact. A building in North Carolina, located within 45 meters of a 42-meter water tower was used in the study. Within a 5-month period, five separate lightning discharges occurred in the area. While the building itself was never directly struck, it did absorb a high degree of the ground voltage that was discharged from the near-by strikes. The result was “deaths of two trees, a fire in electrical equipment, complete destruction of all phone wiring, and severe damage to electrical fixtures.” (NASA, Science Dept, “Human Voltage”, June 18, 1999) Unfortunately, this kind of damage to unprotected equipment is not uncommon. The National Lightning Safety Institute estimates that damages of this nature, cost companies and individuals around $4 billion to $5 billion annually. Further punctuating the risk of surge damage, the U.S. National Lightning Detection Network estimates an average of 25 million cloud-to-ground strikes each year. Of course, lightning strikes are not the only originators of high voltage surges that can cause system damage. Transmission line surges, wiring errors, ground loops, and internal complications can also cause transient voltage to run unwanted across networks, phone lines, serial communication systems, and other valuable equipment.

Power surges and lightning strikes cost over $4 billion annually The larger the building, the higher the risk of transient voltage entering due to transmission spikes or lightning strikes.

Ground Voltage: An Ever Changing Wave of Potential Destruction

A brief review of what causes the phenomenon of high ground voltage will be helpful in understanding how industrial locations can effectively protect themselves against costly electrical component and equipment damage. When a high surge of current is released into the ground by a lightning strike (or even something similar like a downed power line), the energy spreads out like a wave. Imagine a large rock being dropped into a still pond. The ripples are more frequent and intense at the point of origin, growing longer and less intense as the wave moves outward. Similarly, the ground potential at the release point can be hundreds of volts higher that it will be even a few hundred feet away. This difference in voltage levels is the cause of the trouble. As the current moves through the ground, it naturally wants to find a way to equalize and to travel along the path of least resistance. An industrial building found along this path will be connected to the ground, have buried grounding wires, cables and other access points where the current can enter the structure. These wires provide an exponentially easier path for the high voltage to travel across and attempt to equalize. The result can be large amounts of current entering the building at multiple entry points. It should go without saying that the larger the structure, the higher the potential of transient voltage entering. The damage occurs when this high voltage hits equipment and components that are not capable of handling the sudden surge – the effect is over $4 billion annually in the United States alone. Ground Voltage Illustration (Click here for full sized image)

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