Visit Times: 423
1- Surge Arrester(SPD)
Arstr Surge (Surge Protective Devise-SPD) is the term IEC in devices that want to limit transient voltages (Transient Voltages) and currents are unusual. It has different names in different countries. sometimes the name of the technology used.
3-1- Surge Arstr silicon carbide (SiC)
Until recently the conventional method of surge protection against lightning Arstrhay silicon carbide (SiC), respectively. The surge Arstrha a combination of a series of air gaps and are made with resistance against the Occupation spark, after the act, the power system will be capable of recovery. For those of flow reduces resistance and are approximate phase current and voltage to zero after reaching the nominal system voltage waveform, flow is not restored.They (residual voltage) of the surface to be less protective equipment. Usually the resistance of the semiconductor silicon carbide (SiC) are made with the same properties. Silicon carbide arrester, consisting of a silicon carbide resistance, characterized by non-linear VI series is an air gap. When the voltage is greater than the voltage spark, creating a spark across the air gap, increased impedance path to prevent sparks from a sharp increase in the flow. Air gap spark gaps as it is said to be active, it is designed so that after some time the voltage spark, spark blocked.SiC arresters shall be added to any voltage power frequency because the cause of the short circuit to ground and pass much of their energy and die. SiC arresters due to lightning and switching voltage level to a certain extent reduce the amount depends on the nominal voltage surge arrester. Switching voltage with high energy discharge current is applied too much for a long time, can cause burning electrodes surge arresters and surge arresters This problem limits the application of this type, and also causes the endurance level insulation higher equipments is selected. In such cases should be selected Brqgyrhayy with higher nominal voltage to the voltage of the switching not function. The new type SiC arresters, to reduce losses (life, strength, energy) and to switch off the spark arrester in wave after removing the air gap and consequently blocking the flow of magnetic methods are used. SiC arrester with extinguishing magnetic energy three times higher than the ordinary kind of tolerance is required because of losses following the minimum is 1. The surge arresters are used in high voltage networks.
3-2- Surge Arstrhay type metal oxide (MOV)
New type of surge Arstrha block with non-linear electrical resistance of the metal oxide. These blocks are known to MOV. Since about 95% of the ingredients of block MOV to zinc oxide (ZnO) forms, as they are also called ZnO arresters. The constituent components arresters ZnO, including zinc oxide and small amounts of other metals such as bismuth oxide, cobalt, antimony and manganese-oxide. Ultrafine particles of zinc oxide and other metal oxide after condensation formed on the disk and in certain sizes. Then cooked at high temperature for this disc are ceramic. The disk was series cylindrical chamber and form the ZnO arrester. ZnO block has a voltage characteristic - flow is very nonlinear and have excellent energy absorption capacity. In the wake of this surge Arstrha does not exist, that the impact is reduced by reducing the voltage and the voltage (nominal voltage system) can not continue. Therefore, this type of surge arresters Arstrha in practice than they are warm and repeat their performance is less a problem. Another advantage of this type of surge arresters, speed and performance in frontal wave. This means that the delay in the surge Arstrhay with air gap is much lower in this type of surge Arstrha.Due to the lack of air gap allows parallel surge arrester is ZnO. Thus, it can withstand high surge currents Arstr in front of them. By comparing the voltage characteristic - the block of SiC, ZnO becomes clear that the nominal voltage of the network, block the flow of ZnO is less than one mA. While this amount is higher for SiC block. Arstrhay ZnO surge voltages can withstand the power frequency to a person with respect to these characteristics, not even in the ground systems (phase-to-ground fault when the voltage to the other phases can be increased) We can chose a lower insulation level. One of the problems Arstrhay surge ZnO, is leakage current at power frequency. This process may be repeated as mA, but arrester operation, an interface between grains of zinc oxide is burned and increases the leakage current. Another problem caused by the temperature change resistance. This change is more noticeable at low currents. However, by reducing the nominal voltage of the network as a result of temperature resistance, high temperature resistance and reduce the possibility of overheating and there. Despite these problems, but because of the many benefits Arstrhay surge ZnO, the use of surge arresters Arstrha other alternatives are gradually increasing. Some of the benefits of ZnO surge Arstrhay include: 1) perform better than the other surge arresters (better than the other surge arresters, voltage That). 2) low-voltage distribution of waste and also has a very low residual voltage. 3) with very low latency. 4) Return to the normal primary or open circuit. 5) has a characteristic V - linear flow than the surge Arstr SiC. 6) has a very good level of protection. 7) low leakage currents at the nominal operating conditions of the system (less wasted power). The major disadvantage of the surge Arstrhay ZnO, high price compared to other Brqgyrhast and that Arstrhay ZnO surge voltage fluctuations in the system with substantially higher risk of SiC Arstrhay surge and fall injuries.
3- Surge search Arstr LV (Surge Protection Device-SPD)
Surge search Arstr LV (SPD): Surge Protection Device The potential connection to the site where the lightning current arrester device to be used within the structure. Which should have protection class I, B (standard IEC: I and according to the standard VDE: B) is. It should be noted that the use of this arrester is required for structures that LPS. But if LPS is not connected to the structure. In most cases require the use of auxiliary arresters Drtablvy power distribution equipment or the equipment is small or closer. The surge arresters are considered as secondary protection that must be protection class II or III.The arresters class I (B) simulation directs the flow of the lightning strike. The other name is lightning current arresters class I arresters. The arresters class II (C) arresters tested against the current short-term impact is more. And less prone to a direct confrontation with the Impact. And to bring down the lightning current flows through Azbrqgyr used lightning. Overvoltage arresters is another name for class II arresters. The arresters class III (D) surge arresters tested against shock voltages. The arresters class B + C: standard, are mounted between the two arrester class B and C shall not be less than 10 meters. Observe the distance, creates problems for Tablvsazy to fix it, Arstrhay class B + C combination is used. Some Arstrhay Class B has special technology that can be installed immediately next to the C-Class Arstr. The arresters class C + D: standard, are mounted between the two arrester class C and D should not be less than 5 meters. Observe the meantime, problems in the creation of a panel to fix it, Arstrhay class C + D combination is used. According to IEC: where is the line that Arstr over the line early in Earth's protective device, in any case, must be 0.5 meters. And if it exceeds the amount of wiring V type is selected. MCA for lightning protection: Copper 〖〗 ^ 216 mm Aluminum 〖〗 ^ 225 mm Iron〗 〖mm ^ 250 Arstrha surge specifications are as following: Rated voltage (U_c〗 〖= U _n = Nominal Voltage): The arrester between phase and earth is a constant voltage on the arrester to the line voltage is equal. RMS value of the sine wave frequency of 50 to 60 Hz. And maximum continuous operating voltage, maximum permanent voltage that can be applied to the arrester without being impaired in its performance or prevent it. That usually 15% of the rated voltage is increased. Impulse discharge current (I_imp = Impulse Discharge Current): a standard wave waveform is μs 350/10 Arstrhay going to be able to discharge some of their impact on the process. Without damage to the equipment is imported. Nominal discharge current (I_n = Nominal Discharge Current): peak flow into the waveform μs 20/8 that Arstr it is designed for multiple discharge. The total discharge current (I_total = Total discharge Current): the current surge Arstr have the ability to pass the three-phase currents when lightning or switching of the cartridge is connected to the system earth. The flow of the stream discharge in some cases hitting all three phases and when the surge Arstr type of spark gap used. It is calculated in a different way. (Depending on the type used Arstr surge) Voltage protection level (U_p = Voltage Protection Level): refers to the amount of voltage surge Arstr, protect the equipment. And the voltage applied between the terminals of the surge Arstr is tolerable. Its value is calculated by the following equation: Up >=0.8 BIL In which BIL insulation level equipment. Response time (Response Time = t_A): The time it takes the input voltage surge disturbances Arstr to react to system. That the time is shorter this time, Serge Arstr more quickly, disturbance input to the system identify and prevent damage to other equipment.
4- Practical tips about the surge Arstr
Practical tips about the surge Arstr: the selection and installation of surge Arstr there are hints that according to them is very useful. • Most surge Arstrhay produced by reputable companies, are modular and protection module consists of two basic parts. Khashabi form of basic protection module is removed or inserted into it.• A surge may last Arstr short time or many years in a busy switchboard is the protection of electrical circuits and electrical equipment. Arstr life depends on the number and power surge or lightning strike voltages from switching in the network. • As the surge protection module Arstr slide is removed, replace the unit without changing the wiring or the board and quickly done. Of course, almost all the cost of a Arstr surge protection module and base are belong to no value. • Surge Arstr on a green screen that shows the health of the pieces. After aging and the loss of surge Arstr, the red indicator will show that the time to replace it. • Some arresters with auxiliary contacts (remote), which is installed on the base. When worn completely change the color of the indicator Surge Arstr and red, the auxiliary contact is closed and activates the alarm circuit. The possibility of remote monitoring requirements are also available. Abu Bettermann Germany company also has designed an alarm module that immediately after the crash Arstr Siren takes surge. • Surge Arstrha in a variety of single-phase and neutral, neutral, two-phase, two-phase and neutral, three-phase and three-phase and neutral are produced each due to the location and condition, are used. Important in this regard is the lack of internal communication Surge Arstrha with each other. Circuit and function completely independent of each other Arstrha Surge is unlike miniature fuses, MCCB or such equipment, impairment of one of the phases would not be cut every three lines. Two pole at the base and above, only one bus (bus) routes the output to each card that bridge, only to reduce the amount of wiring. Sometimes the bridge is done at the factory in some parts visible and some not visible. Sometimes arbitrary bus used by the user. The point is that although a surge Arstr may be three-phase, single phase busbars for bridge must be used. • the above mentioned point in time when access to Serge Arstr base of 2, 3 or 4 bridge can be utilized. Use a surge Arstr to create a security system, three-phase single-phase or neutral individual (or others), bridge foundations to each other and connect to earth good practice and insist on using some bridge foundations. Of course, this method also has the advantage. If the base paths when one of several bridges damaged, the user is required to replace the entire base, but if something would damage one of the few single base bridge, only replace the damaged base is cost savings. • Under the new standards, surge protection module Arstrhay phase should have the possibility of getting on base in both directions. This goes for all parts of Abu Bettermann Germany that the definition of standards for this equipment is s true. Note that this rule is not subject to the Knoll modules. • When installing surge Arstr must be careful that this piece before residual-current device or any leakage current control relays to be installed. Given that the performance of a surge Arstr of view residual-current device, leakage current, if there is Yd- impact in orbit that takes place several times daily and Serge Arstr Aftd- act, circuit breakers and residual-current device that is not desirable. So the most suitable location to install the surge Arstr in an electrical panel, the first point at the entrance cable to the board is possible after the fuse, the addition circuit protection and electrical appliance fed by the panel, the panel also protects the equipment installed a. (Eg contactors, relays, timers, etc.), usually in the direction of the surge arrester to earth with a bump that number could impact the number of discharge voltage waveforms to be registered on the surge arrester. Arrester at the input transformer substations and as close as possible to all equipment to be installed. In addition, transformer substations arrester installed at the entrance to important equipment such as power transformers and surge arresters installed separately. Abu company Bettermann Germany in addition to the network arresters AC, protection systems for photovoltaic applications, data lines and DSL, phone and ISDN, and also produces antennas, each with a special topology, standards, and hints and subtleties of their own. In the end, the main purpose of the surge Arstrha, sacrificing a piece for maintaining the health of a lot of pieces. In other words, "one for all". In the medium and long term, the use of surge Arstr reduce the cost of many and many times return on investment for this equipment. • Despite the surge Arstr in the system makes detection of leakage current relays, which are surge by more Arstr more leakage current identification system and ultimately by the relay trip command is issued by the relay. And the system includes more outages will be, will become .
2- According to the standard lightning protection zones
LPZ0A: unprotected area outside the building. Direct lightning strike, without interference shield against electromagnetic pulse (LEMP) LPZ0B: external lightning protection system with protected area, without interference shield against electromagnetic pulse (LEMP) LPZ1: indoor area that may include small part of the lightning energy. LPZ2: indoor area that may be of little waves. LPZ3: Zone inside the building (can be metal box consumer) there is no interference or electromagnetic pulse wave.