The power system deals with voltage above 36KV, is regarded as high voltage. Since the voltage level is high, the arcing formed during switching operation is also quite high. Therefore, special care is to be taken during the designing of high voltage switchgear. High voltage circuit breaker is the major component of HV switchgear, thus high voltage circuit breaker ought to have special features for reliable and safe operation. Switching operation and faulty tripping of high voltage circuit are very rear. At time these circuit breakers remain, at ON state, and might be operated after a long period of time. Thus CBs must be dependable enough to make sure of safe operation, as when necessary. High voltage circuit breaker technology has changed drastically in the last 15 years.
SF6 circuit breaker, air blast circuit breaker and minimum oil circuit breaker are mostly used for high voltage switchgear. Vacuum circuit breaker is hardly used for this purpose since till date vacuum technology is not sufficient for interrupting very high voltage short circuit current. There are two kinds of SF6 circuit breaker, that is, single pressure SF6 breaker and two pressures circuit breaker. Single pressure system is the latest and updated high voltage switchgear system, these days. Nowadays SF6 gas as arc quenching medium has become most accepted for high and extra high voltage electrical power system. Though, SF6 gas has strong influence on the greenhouse effect. It has 23 times stronger influence on the greenhouse effect, than that of CO2. Therefore, leakage of SF6 gas in the service life of circuit breaker should be prevented. For minimizing the emission of CF4 – SF6, N2 – SF6 and SF6 gas mixture, might be used in circuit breaker in future, as an alternate of pure SF6. It should always be taken into consideration that, no SF6 gas comes out in atmosphere throughout the maintenance of CB.
Electrical switchgear is a term that comprises of all the switching devices related with mostly the power system protection. Switchgears in substations are situated on both the low voltage and high voltage side of large power transformers. The switchgear on the lower voltage side of the transformers may perhaps be located in the building, with medium voltage circuit breakers for distribution circuits, all along with protection, control and metering equipment.
Medium Voltage Switchgear Application
An arc furnace is necessary to get switch off and on often. The current to be switched might be from 0 to 8 times of the rated current of the furnace. An arc furnace is be switched on and off at its normal rated current up to 2000A, approximately 100 times per day. A normal, oil, air or SF6 circuit breaker is not at all reasonable for this frequent operation. Typical vacuum circuit breaker is most suitable alternative for this frequent high current circuit breaker operation.
One more application of medium voltage switchgear is single phase railway track system. The major function of the circuit breaker is linked with railway traction system, is to disrupt short circuit, on the overhead catenary system that come about frequently and are transitory in nature. Thus circuit breaker used for this purpose must have, short breaking time for short arcing time, small contact gap, VCB and quick breaking is the best probable solution. In fact arcing energy is much higher in the single phase CB than 3 phases CB. It is much lesser in circuit breaker than that in usual circuit breaker. The number of short circuit takes place in the overhead catenary system much higher than those occurring on electrical transmission system. The medium voltage switchgear possessed with vacuum circuit breaker is most appropriate for traction application.
When the power goes out, the lost productivity can be expensive to a company. Whether a company is operating equipment that cannot be turned off without disturbing output, running computers that teams work on without saving their work as they go, or even demanding to have exit paths lit in a calamity, persistent electricity access is vital. Many establishments have a standby generator on the premises; however having this device adjacent is not enough. Businesses must make sure to have regular maintenance performed on every machine, to guarantee that they turn on when disaster attacks. The most important preventive measure to consider is perhaps switchgear maintenance.
If you are unaccustomed with the inner workings of the machine, you must know that the switchgear is the term for the electrical tools that controls the flow of electricity within an electrical system. It serves two main functions. The first is to avoid short circuits or overloads, and the second is to de-energize circuits for testing. The most common switchgear is circuit breaker that halts the flow of electricity to a circuit as the electric current becomes high. It should be clear why a company needs to have this maintenance performed; if a circuit is blown at a critical time when energy is required, the effects could be disastrous. How may a generator service go about maintenance on this critical constituent?
Finding the perfect Switchgear Manufacturers might also be tricky. One must make sure that they are dealing with thefabricators that have been working with these devices for several years: wide-ranging experience that will let them diagnose any problem. Organizations must keep trained engineers on work, so that once problems are diagnosed, their workersare able to address them. Switchgear maintenance is apparently very important; nonetheless there are a number of additional measures to ponder while designing a plan for your device.
From 3KV to 36KV switchgear system; it is classified like MV switchgear or medium voltage switchgear. These switchgears are of a lot of kinds. They may perhaps be of metal enclosed outdoor type, metal enclosed indoor type, outdoor type with no metal enclosure, and so on. The interruption medium of this switchgear might be oil, vacuum and SF6. The main necessity and requirement of MV power network is to disrupt the current in faulty condition irrespective of what kind of CB is utilized in the MV switchgear system. It may perhaps be competent of functioning in other conditions as well. Medium Voltage Switchgear should be highly capable of:
1) Usual ON/OFF switching operation.
2) Short circuit current disruption.
3) Switching of capacitive and inductive currents.
4) Several special applications.
All the above stated function should be carried with high degree of security and consistency.
Short Circuit Current Disruption
The main attention of circuit breaker design is that every circuit breaker must be competent of interrupting short circuit current with high degree of protection and consistency. The number of faulty tripping occurred in total life span of circuit breaker generally depends upon the location of the system, quality of environment condition and system. If the tripping number is high, the excellent option is vacuum circuit breaker since it might not need any maintenance till 100 faulty trippings with short circuit current till 25KA. While other circuit needs maintenance after 15 to 20 faulty trippings with same short circuit CB current.
The reunited substations in rural areas are usually of outdoor type, and the majority of them are unattended sort. Therefore for this kind of applications maintenance free outdoor form, medium voltage switchgear is most appropriate. Porcelain clad vacuum circuit breaker meets this requirement against the usual indoor kiosks.
Switchgear, it is electrical or switching equipment which is used in the transmission of electricity. It is a component which has the most vital function in the electrical system. Switchgear are supposed to be the most essential and necessary component, without which the whole flow of the electric system could stop or come to a hault. Electrical switch gear is extremely necessary in the eletrical power system at every switching point.
Since, it is the most vital and necessary component of the electrical power system, therefore, it should be fabricated and procured from the renowned and industry’s reputed switch gear fabricator. The industry availing these switch gear should make sure that the switch gear which they are procuring from the manufacturer fabricates these switch gear from the industry’s most renowned and reputed manufacturer.
The quality of the product decides its operational life. So, for even any minute or tiny electrical equipment to function well, it is necessary that it should be fabricated from the best quality raw materials. It is only if the manufactured product is fabricated from the richest raw material, that it would produce a product which is way beyond the average life product. This is the very reason why Switchgear Manufacturers should be selected after stern research and feedback from various other clients’ where they have sourced their product. For a product to function well, it is vital that the switchgear should be fabricated by the most experienced and skilled professionals, so that their manufactured product is as per the international standard. Besides, it should also be noted that the professionals who are given the charge of fabricating these high end machines, machinery, circuits, panels; possess huge years of experience. With experience comes proficiency. And if proficiency is not attained, then there is little possibility that the fabricated product is as per the international norms.
In an electric power system, switchgear is the amalgamation of electrical disconnects circuit breakers, fuses or switches used for controlling, protecting and isolating electrical equipment. Switchgears are used both to de-energize tools for allowing work to be done and to clear faults downstream. This kind of equipment is straight linked to the dependability of the electricity supply.
The very initial central power station used was an easy open knife switch; which was mounted on insulating panels of asbestos or marble. Power levels and voltages swiftly escalated, making opening physically operated switches too risky for anything other than isolation of a de-energized circuit. Oil-filled tool permitted arc energy to be contained and carefully controlled. By the early in 20th century, a Medium Voltage Switchgear line up would be a metal enclosed structure with electrically functional switching elements, utilizing oil circuit breakers. Nowadays, oil-filled equipment has mostly been replaced by air-blast, SF6 equipment or vacuum, or letting large currents and power levels to be securely controlled by an automatic equipment integrating protection, digital controls, communications and metering.
In an electric power system, switchgear is the mixture of electrical disconnects fuses, switches or circuit breakers used for controlling, protecting and isolating electrical tools. Switchgears are used both for de-energizing equipment to let the work to be done and to clear off the faults downstream. This kind of equipment is directly connected to the dependability of the electricity supply.
Usually, switchgears in substations are situated on both the low-voltage and high-voltage side of large power transformers. The switchgear present on the low voltage side of the transformers may perhaps be situated in a building, with intermediate voltage circuit breakers for the distribution circuits, alongside with metering, protection and control equipment. For industrial applications, a switchgear and transformer line-up may possibly be united in one housing known as USS or unitized substation.
Switchgears are as aged as electricity generation. The initial models were very ancient: all constituents were merely fixed to a wall.
Electrical switchgear functions with high voltages of electricity passing throughout them continually, the electricity could be thrown out of the switchgear and be injurious to people. Special matting is obtainable to be placed at the foot and ender of the equipment. Rubber is prevention to electricity; it does not conduct it and is thus a defensive measure against electricity. Rubber Matting is obtainable for Electrical Switchgear ; it is security matting for both low voltage & high voltage.
These mats are quite a much an indispensable if one wants their company to fulfill all of the safety regulations and current health; they also defend the team members, producing a safer working surroundings, giving the less grounds for concern. If one is in need of some of this then it is recommended to have a look through the search engines, one would come across a lot of vendors therefore find the most reasonable one and the one which best suits the demands and requirements of your company.
An electric power system used in involvement with the term switchgear refers to an amalgamation of electrical disconnects, circuit breakers, and fuses.
Using the combination of the two kinds of switchgear maintenance is the most utilized. In this maintenance graph, specific parts of the equipment like, warning lights are left to be repair only whilst they stop working. Other more imperative parts are on a maintenance schedule and tested habitually. This plan works well when the shutdown cost of this tool balances the cost of the maintenance agenda and plan.
Determining a kind of plan for you switchgear maintenance, comes down to two contemplations. How significant is this part of the grid and matching the cost of maintenance with the price of shut down. What you select is up to you, as long as you keep in mind that no one wants to be with no power.