Guide to Shop Cable Fault Test Procedure in NOYAFA

Guide to Shop Cable Fault Test Procedure in NOYAFA

2021-11-04
NOYAFA
24

On this page, you can find quality content focused on Cable fault test procedure. You can also get the latest products and articles that are related to Cable fault test procedure for free. If you have any questions or want to get more information on Cable fault test procedure, please feel free to contact us.

Cable fault test procedure is especially favored by customers among SHENZHEN NOYAFA ELECTRONIC CO.,LIMITED's product categories. Each is made from only carefully selected materials and is quality tested before delivery, making it meet top-notch quality standards. Its technical parameters are also in line with international standards and guidelines. It will effectively support users' today and long-term needs.With a mature marketing pattern, NOYAFA is able to spread our products to the worldwide. They feature high cost-performance ratio, and they are bound to bring better experience, increase the revenues of customers, and result in the accumulation of more successful business experience. And we have received a higher recognition in the international market and gained a larger customer base than before.Service is an essential part of our endeavor at Best Cable Tester Supplier in China _ Noyafa. We facilitate a team of professional designer to work out customization plan for all products, including Cable fault test procedure.
more products
recommended articles
Info Center News
Cable Fault Test Procedure
Cable Fault Test Procedure
When using cable fault tester (echo method) to test cable fault, the following procedures shall be followed: â‘´ multimeter, megger or judge the nature of cable fault from the cable pre-test results. (2) select the appropriate test method according to the nature of cable fault: the pulse method is best used for low resistance fault and open circuit fault. Of course, the flashover method can also be used for low resistance fault. Flashover method (impulse l method) is best used for leakage high resistance fault, and direct flashover method can also be used for some leakage high resistance faults, but this is usually not done. Direct flashover method is best used for flashover high resistance fault, or both methods can be used to measure and compare each other to improve the accuracy of judgment. (3) select the working grounding point, and lead out two grounding wires respectively from the selected grounding point, one to the ground of the instrument and the other to the ground of the high-voltage equipment. The selection principle of working ground wire is to ensure that the test phase and it form a closed loop, so that the instrument can obtain the correct test waveform. It should also be noted that the working ground wire must be connected with the system to make the human, instrument ground, high-voltage equipment ground and the tested cable ground in the same position. To ensure personal safety and integrity of instruments and equipment. If the cable is in phase to phase fault, the working ground wire must be one of the phase wires, and the phase wire as the ground wire must be connected with the system ground. For the cable with lead-free bushing, most of the faults are discharged to the earth or space during the high-voltage flashover test. Theoretically, the fault also forms a closed loop relatively to ground or space, but in fact, the equivalent impedance in the loop is quite large, so the correct test waveform can not be obtained on the instrument. In case of this situation during the test, the method of directly fixing the suspicious fault point can be adopted to solve it. No matter what ground wire, its grounding point must be reliable. (4) test the total length of the cable with the pulse method to calibrate the radio wave transmission speed of the tested cable. (5) rough test the fault point according to the selected test method. (6) fix the fault point after rough measurement.
The Benefits of Using the Right Non Contact Voltage Tester
The Benefits of Using the Right Non Contact Voltage Tester
You hear continuous chirping and see a series of flashes confirming that the tester has detected the voltage. This type of voltage tester allows you to test voltage without having to open or splice wires. This tool can also be used to dim the basement in situations where the light does not work, a small but helpful feature as it is the only model we have tested.In fact, the mere presence of an electric field can trigger this type of voltage tester. Non-contact voltage testers work by measuring a small amount of current coupled to the circuit between the tester and ground. Since they are light, they can detect this current without direct contact.A contactless tester is a device which allows the user to check the voltage of a variety of electrical appliances without touching wires or parts. The functioning of these devices is based on the use of capacitor couplings to detect electric fields. The built-in sensors at the top of the tester detect the presence of voltage without touching the conductor, socket or power cable.Volt sticks are designed for a specific purpose: to detect the presence of AC voltage. The electric fields connected to the AC voltage are present in the current conductor, and the reason for this is the requirement of direct contact with the conductor. Another reason is that electric fields have to build up and collapse in order to induce a current in the volt rod circuit, which happens with alternating voltages.If you refer to the capacitors in the video above, you can see that the current flows at an AC voltage. With a DC voltage, the electric field must build up and remain in one direction until a current is induced in the voltage stick circuit, and since there is no volt stick in the circuit it does not indicate the presence of a DC voltage. This is the reason why testers do not work with DC capacitors and why transformers do not work with DC voltage.A few ticker markers, including the Southwire Dual Range non-contact voltage tester can detect two voltage ranges. The higher voltage range is the default, while the lower voltage range (tension range) at the upper end is kept at 1,000 V. Most voltage testers do not register voltages below, giving Southwire a significant advantage over simpler models.Electrical testers are a good value option with impressive IP67 water resistance. Mid-range models such as the SouthWire non-contact voltage tester are designed to withstand the elements. If you need an outdoor quality tester, you will appreciate the IP67 waterproof housing of these pins.The Small Non-Contact Voltage Tester (NCVT) is ideal for NCVT electricians working with HVAC, ventilation and air conditioning systems (HVAC). Not only is it the most reliable model in the price range of non-contact voltage testers, but also has the new Voltbeat technology that enables self-testing. When something goes wrong the problem can be detected by the sensor or from a device such as a nearby voltmeter or oscilloscope.
Things You May Want to Know About Tester
Things You May Want to Know About Tester
An overview of testerRichard Alexander Bevan (14 July 1834 - 18 February 1918) was a British banker and philanthropist. He is known as "the father of Cuckfield."Certifications of testerThe ANZTB offers the following certifications:ISTQB Foundation CTFLISTQB Foundation Performance Tester CTFL-PERISTQB Foundation Model Based Tester CTFL-MBTASTQB Certified Mobile Tester CMTISTQB Foundation Usability Tester CTFL-UTISTQB Advanced Test Manager CTAL-ATMISTQB Advanced Test Analyst CTAL-ATAISTQB Advanced Technical Test Analyst CTAL-TTAISTQB Advanced Test Automation Engineer CTAL-TAEISTQB Advanced Security Tester CTAL-STThe contents of each syllabus are taught as courses delivered by ISTQB Accredited Training Providers. They are globally marketed under the brand name "ISTQB Certified Tester".After the examination, each successful participant receives the "ISTQB/ANZTB Certified Tester" Certificate.What diagnostic tester can I use to check for a shortage or burned wire.?S&G Tool Aid Heavy Duty Circuit Testers w/Retractable Wire - 6"" Features an extra long wire that stretches up to 12 feet for use, then automatically retracts. Rating: No user ratings [rate this item] See All Tools | See More Like This Amazon Find Other Tools...• Like this One• By S&G Tool Aid• From Amazon• In this Price Range (around $15) $14.94Buy at Seller S&G Tool Aid Heavy Duty Circuit Testers w/Retractable Wire - 3-1/2"" Features an extra long wire that stretches up to 12 feet for use, then automatically retracts. Rating: No user ratings [rate this item] See All Tools | See More Like This Amazon Find Other Tools...• Like this One• By S&G Tool Aid• From Amazon• In this Price Range (around $14) $14.44Buy at Seller Lisle Spark Tester Tests Spark Plugs, Spark Plug Wires and Coils Without Puncturing the Wire. With the engine running, place the grooved end of the tool over the plug wire. Rating: No user ratings [rate this item] See All Automotive Amazon $6.31Buy at Seller Continuity Tester/Pocket Flashlight This Combination Continuity Tester Flashlight instantly tests fuses, extension cords, switches, sockets, short curcuits, broken wires, faulty appliances, auto circuits, etc. Rating: No user ratings [rate this item] See All Tools | See More Like This classicgarage Find Other Tools...• Like this One• From classicgarage• In this Price Range (around $6) Related Searches:• continuity tester $6.50Buy at Seller Extra Long Circuit Tester For use on cars, RV, trucks, motorcycles, and snowmobiles Use to check electrical circuits and accessories Wire stretches to 12 ft. for use, then automatically retracts Probe... Rating: No user ratings [rate this item] See All Tools | See More Like This classicgarage Find Other Tools...• Like this One• From classicgarage• In this Price Range (around $12) $11.96Buy at Seller LED Circuit Tester ACTRON LED CIRCUIT TESTER One compact, convenient tool tests spark plus wires and more! Rating: No user ratings See All Parts | See More Like This JC Whitney Find Other Parts...• Like this One• From JC Whitney• In this Price Range (around $15)• With Attention Needed: Short Title• With Type: Electrical Systems $14.99Compare Prices Spark Tester and Indicator LISLE INLINE SPARK TESTER AND SPARK INDICATOR Two easy-to-use, affordable tools designed to check the ignition system and spark plugs, coils and wires. Rating: No user ratings See All Automotive JC Whitney $16.99Compare Prices Grip 20072 Extra Long Heavy Duty Circuit Tester For use on caers, RV, trucks, motorcycles, and snowmobiles Use to check electrical circuits and accessories Wire stretches to 12 ft. for use, then automatically retracts ... Rating: No user ratings [rate this item] See All Tools | See More Like This Tool King Find Other Tools...• Like this One• From Tool King• In this Price Range (around $14) $13.99Buy at Seller Performance W5207 Multi-Use Repair Kit Great for use on automotive, marine, industrial and agricultural applications Contains: Wire crimping tool, 6-12 Volt tester, slotted screwdriver, Phillips screwdriver, blade... Rating: No user ratings [rate this item] See All Tools | See More Like This Tool King Find Other Tools...• Like this One• From Tool King• In this Price Range (around $22)• With Type: Electrical Systems $21.99Buy at Seller Lisle Electrical Circuit Tester The ''Handy Hooker'' Circuit Tester is made with a hooded probe that protects your fingers and automatically centers the wire. Rating: No user ratings [rate this item] See All Automotive Amazon
Principle of Buried Cable Fault Tester
Principle of Buried Cable Fault Tester
Compared with buried wires, buried wires and cables have been used in China for decades. The buried cable fault tester has developed from resistor bridge, capacitor bridge detection and standing wave detection at the beginning of Zui to flashover detection. The development trend of instruments and equipment has experienced the flash detector for general oscilloscope tube display information and the flash detector for storing oscilloscope tube display information. Up to now, intelligent instruments and equipment have been developed, produced and manufactured. The buried cable fault tester adopts large-scale integrated circuit chip, electronic computer solution technology, LCD display technology and other new technology applications, new technologies and new processes. After the wire and cable testing equipment is improved, the common faults of ground buried double eyelid are detected, which has good practical effect and high efficiency. After many practical activities, the common faults of a buried cable double eyelid are generally detected. The buried cable fault tester has a high success rate within 30 minutes from the beginning to the end. Principle of buried cable fault tester 1. The buried cable fault tester uses a unique acoustic frequency vibration sensor and low-noise special components as external components, which further improves the sensitivity of instrument and equipment designation and relative path detection. In terms of signal analysis technology, the distance between the common fault points of digital display information and the sensor technology camera greatly eliminates the one sidedness of designation. 2. When detecting the fault of buried cable, the common fault cable in the empty frame in the cable trench. In the past, the vibration sound of the whole cable makes all the designated instruments helpless, and it is impossible to judge the specific address of the closed common fault. Now, if the controller camera of the instrument touches the common fault cable or the nearby cable line, the information can be directly displayed, and the common fault spacing and orientation can be quickly identified without effort. 3. Based on the basic theory of DC response cancellation and high DC notch technology, the buried cable fault tester greatly improves the suppression and anti-interference of 50Hz DC data signal in the natural environment of strong power frequency electric field, and reduces the specified blind spot. In terms of the function of instruments and equipment, the acousto-electric technology is used to accept the photoelectric technology, which reasonably gets rid of the difficult problem caused by the impact of natural environmental noise on the designated site. In particular, the large digital display information of common fault spacing eliminates the operator's specific analysis of complex wave type, and replaces the rough distance measurement function of flash detector to a considerable extent. For the common fault cable hundreds of meters long, the designation can be carried out without rough measurement, which is truly efficient, rapid and accurate. Using 15z amplitude modulation radio wave and amplitude detection technology for relative path detection and deep measurement of cable laying, the influence of TV line frequency on the designated instrument in the original equal amplitude 15z video signal is prevented. 4. The fault detection of buried cable is very simple in practical operation. You can turn on the main power switch without shifting gears and selecting functions. Compact structure, exquisite and modular design, which is conducive to on-board maintenance and complete functions. Buried cables are widely used in recent years. Therefore, there are many ways of buried cable fault tester, which are not well understood by rural welders and repair and test workers. There are common faults in the ground buried line. If there are no excellent instruments and equipment and good test standards, the common faults can not be removed within the service guarantee period of the power supply system company, which not only delays time and wastes human resources. And affect normal life and industrial production.
Precautions for Use of Cable Fault Tester
Precautions for Use of Cable Fault Tester
The tester adopts low-voltage pulse method and high-voltage flashover method to detect various faults of cables, especially the flashover and high resistance faults of cables can be tested directly without burning through. If equipped with acoustic method pointing instrument, it can accurately determine the precise position of the fault.Precautions are as follows:1) First of all, it is necessary to list the possible causes of the fault and the basic situation of the cable, such as whether the fault is caused by operation or pre-test, whether it is a new cable or a cable with long operation time, the approximate length of the cable, whether there is a joint in the middle of the cable, whether the cable has failed before, whether the cable is directly buried or laid in the cable trench, and the type of cable, etc.2) Make sure that the cable is tested only when there is no power. Both ends of the cable of the cable fault tester must be disconnected from other lines to ensure that the cable is dead and the surrounding environment of the cable is in a safe state.3) The tester must pay attention to the operation safety. Before wiring with the cable each time, connect each phase line of the cable to the ground with a short line for discharge. During discharge, one end of the short line must be grounded and the other end must be connected to each phase line of the cable for discharge. For other electrical appliances, such as capacitors, test transformers, etc., pay attention to discharge before wiring and removing the connecting wire. In short, we should form operation habits and be not afraid of trouble. Before each operation, first pay attention to whether the operating electrical appliances are connected with the circuit, and then discharge before operation.4) When testing the cable fault tester, first use the low-voltage pulse function of the flash tester to test the full length of each phase of the cable respectively to see whether the test waveform is consistent during the three relative tests. For most high resistance faults, the test waveforms of each phase are consistent. For low resistance fault and high resistance fault with open phase fault, the fault phase test waveform is inconsistent with the total length of the tested cable, so the fault distance can be measured directly with low-voltage pulse.5) When the high voltage flashover method is used for testing, whether the cable fault is high resistance fault or low resistance fault, the high voltage impulse flashover method can be used for testing. For the low resistance or broken line fault that can directly test the fault distance with low-voltage pulse, it is generally necessary to use high-voltage impulse flash for verification test and accurate location of fault point.
New Technology of Optical Fiber Communication
New Technology of Optical Fiber Communication
1. Concept of WDMWDM (wavelength division multiplexing) technology is a technology that transmits multiple wavelength optical signals in one optical fiber at the same time.The basic principle of optical wavelength division multiplexing (WDM) is that the optical signals of different wavelengths are combined (multiplexed) at the transmitting end and coupled to the same optical fiber on the optical cable line for transmission, and the optical signals of combined wavelengths are separated (demultiplexed) at the receiving end for further processing, and the original signals are recovered and sent to different terminals. Therefore, this technology is called optical wavelength division multiplexing, Referred to as optical wavelength division multiplexing technology.How wide is the bandwidth of optical fiber?As shown in Fig. 7.6, there are two low loss transmission windows in the optical fiber: the wavelength is 1.31 μ m(1.25~1.35 μ m) Window, corresponding bandwidth (| Δ f|=|- Δλ c/ λ 2|, λ and Δλ Are the central wavelength and corresponding band width respectively, C is the speed of light in vacuum) is 17700 GHz; Wavelength 1.55 μ m(1.50~1.60 μ m) The corresponding bandwidth is 12500 GHz.When the two windows are combined, the total bandwidth exceeds 30thz. If the channel frequency interval is 10GHz, ideally, one fiber can accommodate 3000 channels.At present, some optical devices and technologies are not very mature, so it is difficult to realize optical frequency division multiplexing (OFDM) with dense optical channels. In this case, wavelength division multiplexing with small channel spacing in the same window is called dense wavelength division multiplexing (DWDM).At present, the system is an optical communication system composed of 8, 16 or more wavelengths on a pair of optical fibers (single optical fiber can also be used) in the 1550nm wavelength range, in which the spacing between each wavelength is 1.6nm, 0.8nm or less, which corresponds to the band width of 200ghz, 100GHz or narrower.WDM, DWDM and OFDM are not much different in essenceIn the past, technicians used to use WDM and DWDM to distinguish between 1310 / 1550nm simple multiplexing and 1550nm intensive multiplexing, but at present, DWDM technology is used in telecom applications.Since the multiplexing of 1310 / 1550nm exceeds the gain range of EDFA and is only used in some special occasions, WDM is often used to replace DWDM.WDM technology is of great significance for network upgrading, developing broadband services (such as CATV, HDTV and IP over WDM), fully tapping the potential of optical fiber bandwidth and realizing ultra-high speed optical fiber communication. Especially WDM and EDFA have a strong attraction to modern information network.At present, "erbium doped fiber amplifier (EDFA) dense wavelength division multiplexing (WDM) non-zero dispersion optical fiber (NZDSF, i.e. G.655 fiber) photonic integration (PIC)" is becoming the main technical direction of long-distance high-speed optical fiber communication lines in the world.If all optical fiber transmission links in an area are upgraded to WDM transmission, we can set an optical cross connection device (OXC) for cross connection of optical signals in wavelength units or an optical add drop multiplexer (OADM) for optical uplink and downlink at the intersection (node) of these WDM links, and a new optical layer will be formed on the physical layer originally composed of optical fiber links.In this optical layer, the wavelength channels in adjacent optical fiber links can be connected to form an optical path across multiple OXC and OADM to complete end-to-end information transmission, and this optical path can be flexibly and dynamically established and released according to needs, which is the eye-catching and new generation WDM all-optical network.2. Basic form of WDM systemOptical wavelength division multiplexer and demultiplexer are the key components of WDM technology. The device that combines signals of different wavelengths and outputs them through an optical fiber is called multiplexer (also known as multiplexer).On the contrary, the device that decomposes the multi wavelength signal sent by the same transmission fiber into each wavelength and outputs it respectively is called demultiplexer (also known as demultiplexer).In principle, this device is reciprocal (bidirectional reversible), that is, as long as the output and input of the demultiplexer are used in reverse, it is a multiplexer.Therefore, the multiplexer and demultiplexer are the same (unless there are special requirements).The basic composition of WDM system mainly includes the following two forms: dual fiber unidirectional transmission and single fiber bidirectional transmission.(1) Dual fiber unidirectional transmission.Unidirectional WDM transmission means that all optical paths are transmitted in the same direction on one optical fiber at the same time.As shown in Figure 7.7, dimmed signals with different wavelengths containing various information will be sent at the transmitter λ 1, λ 2,…, λ N is combined by optical multiplexers and transmitted unidirectionally in one optical fiber.Since the signals are carried through different light wavelengths, they will not be confused with each other.At the receiving end, signals of different wavelengths are separated by optical demultiplexer to complete the task of multi-channel optical signal transmission.The principle of transmission through another optical fiber in the opposite direction is the same.(2) Single fiber bidirectional transmission. Bidirectional WDM transmission means that the optical path transmits to two different directions on one optical fiber at the same time. As shown in Figure 7.8, the wavelengths used are separated from each other to realize bidirectional full duplex communication.Several key system factors must be considered in the design and application of bidirectional WDM system:For example, in order to suppress multi-channel interference (MPI), we must pay attention to the influence of light reflection, isolation between bidirectional paths, type and value of crosstalk, power level value and mutual dependence of two-way transmission, optical monitoring channel (OSC) transmission and automatic power shutdown, and use bidirectional fiber amplifier at the same time.Therefore, the development and application of bidirectional WDM system are relatively demanding, but compared with unidirectional WDM system, bidirectional WDM system can reduce the number of optical fibers and line amplifiers.In addition, by setting an optical add drop multiplexer (OADM) or optical cross connector (OXC) in the middle, the optical signals of each wavelength can be merged and shunted, and the wavelength add / drop and route allocation can be realized. In this way, the inserted or separated signals can be reasonably arranged according to the traffic distribution of optical fiber communication lines and optical networks.3. Performance parameters of optical wavelength division multiplexerOptical wavelength division multiplexer is an important part of wavelength division multiplexing system. In order to ensure the performance of wavelength division multiplexing system, the basic requirements for wavelength division multiplexer are:• low insertion loss• high isolation• flat in band and steep out of band insertion loss• good temperature stability• multiple channels• small size, etc(1) Insertion loss insertion loss refers to the additional loss caused by the addition of optical wavelength division multiplexer / demultiplexer, which is defined as the ratio of optical power between the input and output ports of the passive device, i.e(7.1)Where Pi is the optical power sent into the input port; Po is the optical power received from the output port.(2) Crosstalk suppression system crosstalk refers to the influence degree that the signals of other channels are coupled into a channel and degrade the transmission quality of the channel. Sometimes, this degree can also be expressed by isolation. For demultiplexer(7.2)Where Pi is the wavelength λ I is the input optical power of the optical signal, and PIJ is the wavelength λ The optical signal of I is connected in series to the wavelength of λ Optical power of channel J.(3) Return loss return loss refers to the ratio of the optical power returned from the input port of the passive device to the input optical power, i.e(7.3)Where PJ is the optical power sent into the input port, and PR is the return optical power received from the same input port.(4) Reflection coefficient reflection coefficient refers to the ratio of reflected light power PR to incident light power PJ at a given port of WDM device, i.e(7.4)(5) Working wavelength range working wavelength range refers to the wavelength range in which WDM devices can work according to the specified performance requirements( λ Min to λ max)。(6) Channel width channel width refers to the wavelength interval between light sources to avoid crosstalk.(7) Polarization dependent loss (PDL) refers to the maximum change of insertion loss caused by the change of polarization state.
The Evolution of the Handheld Laser Measuring Device in China
The Evolution of the Handheld Laser Measuring Device in China
The Great Wall of China, the Taj Mahal, the Roman Colosseum and the pyramids are just some of the largest and small gauges in the world in critical buildings. The development and mastery of these tools has been crucial to the evolution of the human species. Laser pointers are also used in robotics, for example, laser guidance guides a robot into a target position using a laser beam. Green laser pointers are used for similar purposes in daylight and over long distances. Another common use of lasers in entertainment is the special effects used in laser shows. Clubs, parties and outdoor concerts often use high-power lasers as security for the spectacle. For example, construction companies use high-quality laser pointers to increase the accuracy of displaying certain distances when working on large-scale projects. In astronomy, laser pointers can be mounted on a telescope to align the telescope at certain star locations. Green laser pointers are also used by astronomers for star parties or lectures on astronomy. Laser rangefinders have built-in processing capabilities that allow them to triangulate, calculate and measure distances, as well as calculate area and volume. They are accurate enough to measure long distances and display fast measurement results, compared to traditional bands used for measurement applications. With the various functions that digital handheld meters offer, the demand for these devices via tape increases. A major factor in the growth of hand-held laser rangefinders is the growing construction sector. Noyafa is committed to scientific and technological applications of laser detection. The growing demand for digital measuring instruments for precise measurements and the resulting growing demand for hand lasers and distance meters in the construction industry is a key factor in the growth of the market for hand lasers and distance meters worldwide. Measuring tools continue to evolve with technological advances such as lasers. With the development of mass production of integrated circuits (IC), the measuring tapes have become digital. This is different from 100-foot measuring tapes, which are made of fabric and used to mark the exterior dimensions of large buildings.
Cable Identifier Manufacturers Popularize Science on Information Security of Power System
Cable Identifier Manufacturers Popularize Science on Information Security of Power System
China's science and technology are developing continuously and its economy is growing steadily. In this environment, the development speed of China's power industry is not the same as before. However, in today's society, facing the increasing demand for power in people's production and life, the power industry can ensure people's power consumption only by doing a good job in safe production. Now let the cable recognizer manufacturer popularize some knowledge about power system information security. In recent years, with the rapid development of power grid, especially power grid dispatching automation system, power dispatching control business has become the lifeblood of power system. According to the security protection regulations of power grid, power plant computer monitoring system and dispatching data network, the power control system must be effectively and safely isolated from the office automation system. The above-mentioned isolation means that the dispatching data network used by the power control system must be physically isolated from the public information network and the Internet, and a national power system information security protection system, security responsibility system and security joint defense system must be gradually established. The goal of power grid information security is to prevent the power grid, power plant computer monitoring system and dispatching data network from being attacked, prevent power system accidents caused by attacks, ensure the safe, stable and economic operation of power system, and protect the safety of important national infrastructure. Therefore, building the security protection system of dispatching automation system has become an important task of power grid dispatching automation in the future. Power grid information security has become an important link in the production, operation and management of power enterprises. 1、 Security protection scheme of main station of network dispatching automation system security protection strategy of main station of network dispatching automation system. Security zoning, network dedicated, horizontal isolation and vertical authentication are the basic strategies for security protection of power secondary system. Its core idea is two isolation, namely, effective and safe isolation between control system and office automation system, and physical isolation between dispatching data network, public information network and Internet. 2、 The basic principle of security protection of power real-time data network system. In theory, although the power real-time data network system with absolute security and confidentiality can not be established, if some reasonable principles are followed at the beginning of construction, the corresponding security and confidentiality will be greatly improved. When designing the security mechanism of power data network, we should follow the following principles from the perspective of Engineering Technology: among them, the integrity principle of network information security system comprehensively considers the factors such as security protection, monitoring and emergency recovery. Because the security and confidentiality of network information can not be guaranteed, it is required that when the network is attacked and damaged, the service of the network information center must be restored as soon as possible to reduce losses. Therefore, the security protection mechanism, security monitoring mechanism and security recovery mechanism of information security system should be included. Principle 2: Barrel Principle of security and confidentiality; It is necessary to consider the balance and comprehensive security protection of network data and information. The cable identifier manufacturer believes that it is a necessary prerequisite for designing the information security system to fully, comprehensively and completely analyze, evaluate and detect the security vulnerabilities and security threats (including simulated attacks) of the system.
Location Method of High Resistance Damage in Power Cable Line
Location Method of High Resistance Damage in Power Cable Line
In order to preliminarily determine the high resistance damage in power cable lines, the combination method of high voltage reflection method is usually used: pulse arc method and vibration discharge method. In this paper, we will consider the main ideas embedded in these methods and how they work. In addition, we will discuss the equipment to implement these two methods. 1、 Pulse arc method (ARM) is used to determine high resistance damage. The main idea of pulse arc method is to use a special high-voltage pulse generator. For example, in the arc cable generator of power cable, oil first creates conditions for the generation of high resistance defects and causes short-term arc (breakdown). According to the magnitude of the leakage current and the power of the current source, use one of two ways for the generator to act on the cable line: 1. Smoothly charge KL's own capacity (cable) from the generator current source until breakdown occurs. This method can be used if the leakage is so small that the power supply of the high voltage pulse generator is sufficient to charge before breakdown. For defects with serious leakage, this method is not applicable. 2. Charge the built-in capacitor of the generator to the required voltage (not exceeding the test standard), and then discharge the cable instantaneously. In this case, the high-voltage pulse propagates in the cable, which will lead to failure when it reaches the location of the defect. This method can be used to search for defects on cable lines with serious leakage. In both cases, the use of inductors integrated in the generator will delay the arc combustion time. The current pulse from the breakdown (propagating from the defect to the input of the generator) triggers a synchronous circuit that starts the low-voltage sounding through the cable fault locator (also known as the cable fault tester). The physical characteristics of the arc have low resistance, and the detection pulse of the cable fault locator is also reflected from medium and low impedance defects (short circuit). Advantages of pulsed arc method the pulsed arc method (ARM) for determining high resistance damage has several advantages. This is a non-destructive method, because unlike combustion, the impact of high voltage on the cable is short. Unlike combustion, this method will not reduce the cable parameters as a whole, and will not cause new damage where the insulation resistance is still within the normal range. Arm is actually a high-precision method, because the measurement is actually carried out by pulse method. 2、 The vibration discharge method (ice / attenuation) should deal with high resistance damage. The vibration discharge method is used to find damage on a long cable line, or when the pulse damping of the underground cable fault locator is too large for some reason to apply the pulse arc method. The vibratory discharge method allows you to locate most faults that can be detected using the pulsed arc method, but usually reduces accuracy. It should be noted here that the function of the cable is not displayed when operating by the vibration discharge method. Current oscillation discharge method (current fluctuation method, ice) when the wave current method is used, the oscillation circuit is formed by the system: capacitor on the source side - Cable - low transition resistance (or arc) at the defective part. When the method of vibration discharge through current is used, according to the leakage current value and the power of the current source, here, as with the pulse arc method, one of the two methods of exposing the cable to the generator is used: 1. Smoothly charge the CL capacitor from the generator current source until breakdown occurs. This method can be used if the leakage is so small that the power of the current source is sufficient to charge before breakdown. For defects with serious leakage, this method is not applicable. 2. Charge the built-in capacitor of the generator to the required voltage (not exceeding the test standard), and then discharge the cable instantaneously. In this case, the high-voltage pulse propagates in the and reaches the defective part, resulting in breakdown or large discharge current. This method can be used to search for serious defects. The discharge current pulse returned to the source will charge its capacitor, which in turn. The wave reaching the defect may cause a discharge in it again (in this case, its polarity will change), or if a second discharge does not occur, it will reflect with the same polarity and repeat the process again until all the energy of the initial pulse disappears. These vibrations are displayed on the screen of the cable fault locator connected to the cable through the inductive sensor.
no data
Contact Us
Leave a message
We welcome custom designs and ideas and is able to cater to the specific requirements. for more information, please visit the website or contact us directly with questions or inquiries.
During 15 years development, Noyafa has become the most famous brand in cable testing industry in China. With excellent production capability, reliable quality, good after-sales service, we get good reputation from customers all over the world.
no data
Contact Person:Lory Liu
Contact Us

+86-0755-27530990

If you have any question, please contact Lorry via

wire@noyafa.com

Add:Wanjing Business Center, #2506 Xinyu Road, Xinqiao, Baoan District, Shenzhen, China

Copyright © 2021 NOYAFA | Sitemap 

chat online
Please message us and we ensure to respond ASAP, what product you intrested in?