What is transient overvoltage system? Transient overvoltages term is used in foreign language as surge overvoltages or in short ‘transient’. Transient overvoltages are events which occur in a few microseconds (micro = 1 / 1 000.000) or a few milliseconds (mill = 1 / 1000) and their size changes between 5…10 kV. More overvoltages in these sizes are equal to the 8-10 time endurance limits of electronic devices. What are the problems that are caused by transient overvoltages? The problems grow up in three steps according to the overvoltages size Breakdown: Although, it doesn’t cause any physical harm, it can confuse systems’ analog and digital level and can cause data loss and computer locked ups. System may need a reset. Attrition: If electronic equipments are exposed periodically and continuously transient overvoltages, its life would be shortened and it would have attritions that are cause of possible breakdowns and troubles. Even an incandescent lamp’s life can change with the operating voltage’s 13th power. This means if a 220 volt lamp is worked with 250 volt its life would decrease to the %20. (So 1000 hours working limit would decrease to the 200 hours) Damage: Big transient overvoltages can have damages on equipments, circuit panels and I/O cards. These problems’ possible results: Because of the breakdown in chemical and nuclear facilities’ systems there can be toxic material bleedings. Robotic systems may get out of hand and it can cause damages and breakdowns. There can be damages and breakdowns on medical electronic devices and life-support machines used in hospitals. Because of the damages on telephone centrals there can be pause in communication. Restoration in expensive machines because of the damages. Production pause in factories (Especially in facilities which have CAD-CAMS and which uses computer aided manufacturing) How Does the Transient Overvoltage Occur? Circumstances that create the overvoltage can be gathered in two titles: Lightning : Lightning can cause transient overvoltage either in power, telephone and data communication lines. Lightning releasing is terrifying and it was seen that its current intensity goes up to 530.000 ampere; furthermore, 200.000 ampere is an accepted up limit. (Majority occurs between 2000 and 200.000 ampere.) Electrical Switching Events :  Transient overvoltages caused by electrical switching events is very common and is accepted as a vital interference supply. It creates a magnetic area around the current that passes through a conductive and when the current is cut off (the key is opened) magnetic area diminishes immediately. Energy collected on the conductive, is distributed by induction as transient overvoltage. How Does The Lightning Current Cause Voltage Impacts? The secondary effect of lightning current leads transient overvoltages with two ways Resistant Coupling: Resistant coupling happens when a lightning falls on to buildings or building groups which have an electrical connection among them. If two buildings have a separate grounding system, the building’s grounding system, which is close where the lightning falls, is under the effect of potential tent (voltage gradient) created by lightning. However, the neighbor building’s grounding system, which has an electrical connection with the other, is the reference ground according to the potential tent of the lightning. In this case, circulation currents pass through the electrical connections between them and overvoltages occur on the devices. Induction Coupling: Induction coupling can be defined as a transformer effect between the lightning current and lines. Lightning current at great numbers creates a magnetic area and this area induces voltages in the close lines too. Is it true that underground cables are not affected by lightning current secondary effect? No: Underground cables get affected transient overvoltages by resistant coupling like other cables. Nevertheless, underground cables are not affected from transient overvoltages by generally more weak induction coupling. We have an interruptible power supply. In this case should you need to use transient overvoltage protection system? Yes: Lots of UPS systems do not include any transient overvoltage protection installation. Ones, who claim to have provided the transient overvoltage protection system, only have a small low passer filter. As this filter only provides protection radio frequency interferences, does not provide protection to transient overvoltages with more amplitude that can do more damage. Also, lots of UPS systems have a by-pass connection which is active in errors, over loadings, UPS breakdowns or routine maintenance. Transient overvoltage protection system protects UPS and at the same time its electronic circuits to damages and attrition. What are the events that transient overvoltage impacts cause damages? Damages which were caused by overvoltage showed a terrible increase in eighties. Its reason is thought to use more sensitive electronic measure, control and communication devices more and more in both industry and service institutions. All production time is implemented with PLC units and without computer supported manufacture (CAD-CAM) systems production cannot be dreamed. As giving couple examples from Germany, near Kartsruhe in the town called Worth, there is Europe’s biggest computer controlled truck factory, Daimler-Benz and a national bank in Köln can be counted. Daimler- Benz factory is pervaded an area 1.5kmx1km. In two shifts, 10.000 employees in every shift produce 400 trucks. Material stocks and production control are checked by DC data connection lines connected to computers. In this institution, in the weathers with lightning, production’s stop and related with that reason production loses were being encountered. At last, in 1984, after the overvoltage protection system was established the problem removed. In the second example, in Köln, with the lightning close to a bank’s administration building, overvoltage entered to system caused 2million DM damage in the computer center 120km far away from bank. Following loses were calculated 4 million DM. In our country, we have already witnessed lots of events and solved: In countless institutions, it is complained about how many times their telephone centrals are changed because of burning. Television –Radio transmitting stations are the most open places to danger and after lightning it is worth to see the damages in the cards of ten thousand dollar devices. After implementing overvoltage protection system to Balins FM transmitting, since 1994 there are no complaints seen anymore. In Star TV and Telsim’s transmitting stations, whose electrical works are contracted by us, this system is used reliably. After implementing this protection to electronic scales in cement factories and concrete plants loadcell and card damages are avoided. What is our application style? Institution is examined Grounding system is checked Grounding resistance is measured. If grounding resistance is over the standards additional grounding system is done. The damages that are occurred before or institution’s sensitive equipment sections (like measure-control, computer) take into consideration for the appropriate solution. Suggested system will install by our technical staff. How Does the Protection System Work?In the low voltage system, overvoltage coffers, tied between ground with phases and neutral with ground, in case of a coming impact, as moving from open circuit position to conduction, they extinguish the overvoltage on themselves. In other words, protection coffers take the impact voltage that system was going to expose, on. For this, in the norms of DIN – IEC graded protection was provided. As each degree diminishes the impact voltage a degree in result makes it harmless for the system. For common protection B class, moderate grade C class and sensitive protection D class protection modules are used. Product details in PDF format