AC Surge Protection
Lightning has been scientifically studied for many years, first being investigated by Benjamin Franklin in 1749 with his famous kite and key. The push to study lightning comes from two places, first out of respect for the massive amounts of power that a lightning strike creates and the desire to find ways to harness and exploit it, and second out of fear of the damage it often results in. Lightning strikes have been creating damage and havoc since people have been constructing dwellings, but the need to more fully understand and thus prevent lightning related damage really evolved due to the proliferation of electronic equipment. “Transient overvoltage’s” (TOVs) affect electronic device users, telephone systems and data processing systems by damaging the internal components, as well as taking systems offline. Those involved with many business models rely upon remaining operational in spite of TOVs. These include data systems that experience higher levels of disturbance because they cover large areas, and any system that has grown in its integration of electronic components and is also connected to exposed lightning strike points.
In order to fully understand the situation, we must understand what lighting is. The “lightning flash” is generated when two zones of opposite charge collide within storm clouds or between clouds and the ground. Flashes can be singular or can travel several miles by advancing toward the ground in leaps. When it reaches the ground the “return stroke” takes place. At this point the ionized channel will produce a current of tens of thousands of Amperes traveling either from the ground to the cloud or from the cloud to the ground. When discharge happens we find an impulse current flow ranging anywhere from 1,000 to 200,000 Amperes, this happening within only a few milliseconds. It produces a highly localized strike which creates severe damage at the direct strike point, and the only viable method of protection against direct strike is the classic lightning rod or lighting protection system which draws the strike to it and discharges the current to a specified point.
While the direct strike point is obviously the most gratuitous damage that is produced, many times being accompanied by explosions and fires, the more indirect damage that is produced by lightning strikes is equally problematic. One of the highest instances of indirect lighting damage is a strike to overhead power lines, which destroys the line at the strike point then allows high surge voltages to travel naturally along the conductors and to reach in-line and connected equipment. The extent that the impact that this instance will have on the connected equipment will generally be determined by the distance between the strike and the equipment itself, as the electrical charge will dissipate over greater distances. Another indirect problem is the rise in ground potential, which is brought about by the flow of lightning in the ground causing earth potential increases. These vary by current intensity and local earth impedance. Say an installation is connected to multiple grounds as might be seen in links between buildings, a strike can cause a large potential difference which would damage any equipment connected to the network. Electromagnetic radiation released by the lightning flash can also produce fields that produce strong voltages and currents in lines either connected to or nearby equipment, also damaging it.
Other types of “current based” damage occurs outside of lightning strikes. We will see these “industrial surges” occurring when equipment is switched on or off, and the power to the system is either killed or brought live. This type of damage occurs when motors or transformers are started, when neon or sodium lights are started, power networks are switched on or off, and inductive current creates a “switch bounce,” fuses or circuit breakers are operated, a power line fails or there is an intermittent contact. When these “overvoltages” happen, damage types that are produced include the voltage breakdown of semiconductor junctions, the destruction of the bonding elements of components as well as several other damage types. This type of damage will prematurely age components and systems and produce operational interferences like memory losses, program errors, data transmission errors, and other random operational failures.
The problems associated with overvoltage are controlled through the effective implementation and use of surge protection devices (SPDs.) These devices are designed to create a gap in electrical flow when overvoltage is detected, thus either dead ending or re-directing that electrical flow to a point that is not connected to in-line components. SPDs will not generally help to avoid direct strike damage, but instead are designed to control the flow of electricity that moves from one point to another within a system. How the electrical transient is produced is irrelevant to the job of the SPD, which simply must prevent any flow of power over a certain amount to move past the device itself. In many cases the SPD itself is destroyed by the overflow of power, and will need to be reset or replaced in order to bring functionality back and restore system operations. For businesses that rely on uptimes to be profitable, one can easily see how simple avoidance of equipment damage is only half the battle, the other important aspect is the restoration of system operations as quickly as possible. The more difficult it is to replace the SPD, the longer it will take to restore functionality even in instances where no damage was produced as a result of an effective SPD. This is where the evolution of more technologically advanced SPDs like the Strikesorb products manufactured by Raycap is so important. Improvements to design and makeup of conventional SPD technology will help to avoid more instances of damage, but the ability of Raycap’s Strikesorb devices to immediately return to a fully functional state even after a overvoltage instance sets them apart. Uptimes of systems can be increased dramatically through the integration of Raycap products because the SPDs immediately return to functionality after they perform their duty, and system functionality is completely restored as soon as it can be switched back on, if necessary.
An added value of the use of Raycap “always on” devices is the instances of multiple strikes or switching errors within a period between resets. In most instances, the incident renders the system inoperable and the device itself is no longer providing protection. If another surge follows before the device is replaced or reset, damage can occur to components as if there were not protection in place. During heavy storm activity it is common for multiple strikes to happen within an area, affecting the same equipment and illustrating the need for devices that do not sacrifice themselves and need to be replaced. Raycap provides the highest level of protection against real world events that produce damage to industrial systems.
If you operate an industrial facility that has been impacted by lightning strike damage or other electrical flow issues, contact Raycap directly to learn about the different options that they have been developed specifically to prevent damage of this type. There are no better surge protection devices and systems available worldwide, and Raycap is a leader in surge protection globally.