switchgear design calculation

A minimum height of 2,000 mm below ceilings, covers or enclosures, except for cable basements is required. When load centres for from the transformer substations are to be supplied, it is useful to provide a load centre substation as shown in Figure 5. The calculations shall include the following parameters: Earth resistance of the … Operate the installation from a safe distance. Factory-assembled, type-tested plants with: Metal enclosure in accordance with IEC 62271-200 (VDE 0671-200), Moulded-plastic enclosure in accordance with IEC 62271-201 (VDE 0671-201). Table 1 gives an overview of the configuration parameters and characteristics which may play a part in the planning. The results of the reliability calculations for each consumer are as follows: Those for the system as a whole are as follows: In addition, the contributions of the individual pieces of equipment to the “unreliability” of the network can be quantified. i NEED A STANDARD MV PANEL AND SUB PANEL TO MEET UP OUR SPECIFICATION A NEW PROJECT I AM EMBACKING UPON, Could you email me a copy of this in pdf…. The IEC 62271-200 (VDE 0671-200) standard for metal-enclosed switchgear distinguishes between accessibility level A for authorized personnel and accessibility level B for unlimited access (also for the general public). 608 Switchgear Design jobs available on Indeed.com. Otherwise, for example, high circulating currents could flow or the short-circuit withstand capability of equipment could be exceeded. The advantages of gas-insulated switchgear are: Lower space requirements (up to approx. The switchgear is going to be a GIS (Gas Isolated Switchgear). Load (feeder circuit), power to be distributed (busbar), Bus sectionalizer/ busbar coupler, longitudinal (BCL), Switch-over (BCL) using switch or circuit-breaker, Busbar coupler, transversal (BCT) (double busbar), Grid protection, response times, selectivity criteria, Reserves /service continuity, switch-over times, Interlockings, switching fault protection, Grid protection, selectivity requirements, Numerical ratio of switch panels to circuit-breaker panels, Expandability, electrical / mechanical reserves, Room climate: temperature cycling, humidity, pollution, salt, aggressive gases, Place of installation (spatial requirements), Servicing and maintenance (service life of components), Shock-hazard protection during work in progres, Equipment for control, interlocking, and switching fault protection, Equipment for metering, counting, measured-value transducers, Equipment for monitoring and communication, Damping resistor (for voltage transformer), Grid operation, integration into (industrial) processes and operational procedures, Smaller transportation size and consequently easier shipping, Increased reliability of operation due to hermetically sealed primary switchgear section (adverse impact such as from contamination, small animals, contact, condensation are excluded due to the encapsulation), Maintenance-free primary section (no lubrication and readjustment necessary), Better eco balance than air-insulated switchgear referred to the entire system life cycle, The gas-insulated switchgear is safe to touch thanks to its, HV HRC fuses and cable terminations are only accessible if branch circuits are earthed, Operation is only possible if the enclosure is fully sealed (and any doors closed). Design and Installation of Medium Voltage Switchgear (Facts You MUST Know), Electrical engineer, programmer and founder of, Standards for the Design and Installation of MV Switchgear, Service continuity during work in progress, Estimation of pressure effects according to Pigler, Finite-elements-simulation of pressure load under conditions of arcing, very short tripping times from fast-acting relays, When an accessible compartment of the switchgear is opened…, The busbar and therefore the complete switchgear must be isolated, No partition plates within the panel, no panel partitions to the adjacent panels, Only the supply cable must be isolated. They switch large consumers, mostly in industrial plants, or cable rings which feed switchgear at the secondary distribution level. Use sealed encapsulations or covers instead of encapsulations with openings or meshed wire. With the aid of ultra-modern finite element methods, pressure calculations can be performed in the entire three-dimensionally mapped space over the entire burning time of the accidental arc. Our engineers make sure that they design switchgear as per the customer needs, laws and quality standards. In these cases, the simple ring network concept as shown in Figure 3 is usually preferred. kindly forward single information as well. A calculation of the dynamic pressure load on the operating room, from which an architect or structural engineer may recognize the stress on building structures, is recommended. I am learning more about these MV stuffs. It is normally essential to perform a network calculation (e.g. This article provides general guidance on the factors to be considered in the design of a typical room. This requirement does not apply to walk-in busbar or cable conduits or ducts. SWITCHGEAR AND PROTECTIVE DEVICES 2015 1 | P a g e Lecture Notes on ... arrangement calculation of fault MVA for symmetrical short circuits. with ETAP) are performed in the course of analysis of the actual situation and to assess the target network variants. Generally speaking, typical forms of substation are: The consumer substation from which the energy is distributed at the fed-in line voltage (medium voltage). Furthermore, if the costs of interruptions are known, details of the annual costs caused by interruptions to supply can be presented. Lighting Controls (26 09 23, 33, 36) J. Learn about power engineering and HV/MV/LV substations. rison with a tested reference design by calculation”. Secondary Distribution – At the secondary distribution level, the switchgear is equipped with switches or a mixture of switches and circuit-breakers, where the proportion of switches clearly dominates. The technical data must be verified by type tests. The manufacturing quality is monitored by routine tests. For this reason, appropriate measures in relation to the room situation must be provided for pressure relief. Can I design with cable or trunking from 2500-6000amps. Firstly, these are the switchgear steel sheets and secondly, the absorber sheets to be penetrated. Access is described through instructions of the operating company, and a lock shall ensure safety of access during normal operation and maintenance. CANDIDATES ONLY FROM LIGHTING / SWITCHGEAR SALES with DIRECT / PROJECT SALES, working with ARCHITECTS / CONTRACTORS / CONSULTANTS and BUILDERS. This means that the network concepts presented are mostly not encountered in their pure for, but as hybrids. gears and control gears. Apply to Data Center Technician, Gas Manager, Civil Engineer and more! Networks in which the transformer substations are connected on the medium voltage side are used when those substations are not in intrinsically safe design. System Equipments, Distribution Transformer . Switchgear is a generic term and includes the entire range of switching devices and their combination with associated control, measuring, protecting and regulating equipment. Example of substation design - electrical part 65 14.1 Estimate of the power supplied to a small industrial factory 67 14.2 Calculation of short circuit and coordination of the protections 67 Theory behind calculation of the short circuit current 71 Sizing the electrical installation and coordination of the protections 80 15. GIS are used where you cannot use an open switchgear, which may be because average <35℃ 1 month average <90% The number of outgoing and incoming feeders, Separate operation of parts of the installation required, Operability of certain installation parts required during maintenance work in progress, Switch-over of consumers to different feed-in sections. The switchgear is almost completely equipped with circuit-breakers. Corridors and access ways must be sufficiently dimensioned for work, operation and transportation of components and must have a. Corridor width must not be obstructed by equipment protruding into the corridor, such as permanently installed drives or switchgear trucks in disconnected position. For example insulation level, neutral-point connection, overvoltage protection, short-circuit duration, type of operating area, plant design. If the wrong breaker should be operated inadvertently, this would not have any safety-relevant consequences in the switchgear, since circuit-breakers are capable of making and breaking all load and short-circuit currents, even under earth-fault and other fault conditions. The requirements for configuration and the rated data of the medium voltage switchgear installations are to be deduced individually from the network structure concerned. Design calculations establish minimum guidelines and requirements for generating electrical calculations on projects. IEC 62271-200 (VDE 0671-200) specifies categories of operational availability (LSC, loss of service continuity) of the functional units of a switchgear. University of California San Francisco Medical Center Design Guidelines June 2015 Electrical 3 Section 26 - Electrical I. This manual is intended as a guide for electrical engineers and designers (hereafter referred as Get access to premium HV/MV/LV technical articles, electrical engineering guides, research studies and much more! Gas-insulated switchgear should be used for the medium voltage consumer substation. At the primary distribution level (Figure 1) you will find the. This supplies a simple curve progression for the overload pressure (see Figure 8). The substation, also called secondary unit substation, where the energy is transformed from medium into low voltage and distributed as such. Individual panels and panel blocks can be mounted side-by-side and extended as desired – no gas work required on site, Low-voltage compartment (cubicle) is available in two heights, wired to the switchgear panel by means of plug connectors. the expected value for the frequency with which interruptions are to be expected by consumers in the network, and non-availability (stated in min/a), i.e. If primary side with >2500amps. it seems like those settings for the breakers for the transformers will be higher , even though the 700% is to compensate for the magnetizing current . 40℃, Min. On account of the widely differing structures which result from the demands placed upon them, a distinction is made between industrial and power station service networks on the one hand, and public utility networks on the other hand. 70 % savings with 30 kV) compared to air-insulated switchgear; Smaller transportation size and consequently easier shipping Ith=(kA rms 1 s or 3s) (example 25kA rms 1s) This corresponds to a short-circuit in the immediate vicinity of the downstream terminals of the switching device (see fig.1). In analogy to distribution grids, switchgear can be assigned to the primary or secondary distribution level:Primary Distribution – What is characteristic for the primary distribution level are high load and short-circuit currents and high-end secondary features of the switchgear with regard to protection, measuring, and (remote) control.The switchgear is almost completely equipped with circuit-breakers. It is normally essential to perform a network calculation (e.g. Electrical Panel Design Software - Industrial Power Control (3 phase, 50/60 Hz electrical system, LT electrical panel design software LT, 3 phase electrical panel and switch board designing is no more a tedious and time consuming job now. The required number of series wired cells to achieve the more common DC control voltages for switchgear control is … They describe which parts must be put out of operation during the opening process of an accessible switchgear compartment. Consumers with disturbing perturbations on the grid are separated from consumers placing high requirements on the. This electrical installation handbook, ho-wever, aims to supply, in a single document, tables for the quick definition of the main parameters of the components of … Increased pressure on costs, increased equipment reliability. Therefore, these substations are called load-centre substations. Open switchgears are big and they needed a lot of equipment. In this type of switchgear, all the necessary components of switchgear can be assembled in very limited space. Medium voltage switchgear is used in transformer substations and switching substations, and in secondary unit substations and customer substations (in public utility networks only). The operating room must be equipped with pressure relief openings of sufficient cross section or with a pressure relief duct. Gas-insulated switchgear should be used for the medium voltage consumer substation. Prevent the re-energization by use of non-resettable devices which detect internal equipment faults, incorporate pressure relief and provide an external indication. To get an I cw value suitable to the short-circuit current of the plant: – 5 busbar holders PB3201 at a maximum distance of 425mm (I cw =50 kA) must be positioned. Many medium voltage (MV) indoor switchgear rooms exist worldwide. ... coordinated with the design of the primary protection and essentially it is the second line of The Metal Clad Switchear is fed by two 34KV lines and a tie breaker . This will be 10-15% smaller than an open switchgear. In industrial plants, substations are often installed in the production centres which are also load centres. Tell us what you're thinking... we care about your opinion! Unit Substations (26 11 16) K. Medium Voltage Switchgear (26 13 00) L. Low Voltage Transformers (26 22 00) M. Low Voltage Switchgear (26 23 00) N. Switchboards (26 24 13) with NEPLAN) in order, for example, to take account of the contribution of motor loads to the short-circuit current or to be able to formulate requirements for network protection. (From the “Distribution Switchgear – General catalogue”) BA2000 In=3200 A (IP65); I cw max =100 kA. Back-up supply is then effected through the medium voltage network. system, the system design engineer must have information concerning the loads and a knowledge of the types of distribution systems that are applicable. rms value of maximal short time current. Design calculations may be made either manually or by SPU-approved computer programs. A modular system with ordering options for busbar extensions on the right, left or both sides provides the best prerequisite for this: The medium voltage switchgear is usable as indoor installation in accordance with standard IEC 61936-1 (VDE 0101-1). Design Calculation Of The Earth / Ground Electrode. At last, the pressure relief openings in the switchgear room are defined. with NEPLAN) in order, for example, to take account of the contribution of motor loads to the short-circuit current or to be able to formulate requirements for … Data on the room volume, the area of the free relief cross section and the short-circuit current to be tested are entered into a matrix. When specifying and planning medium voltage switchgear for a substation, functions and influencing factors must be matched and an economically efficient solution must be found among the offerings of manufacturers. The content is copyrighted to EEP and may not be reproduced on other websites. On-site or workshop-built switchgear in accordance with IEC 61936-1 (VDE 0101-1), as it is rarely built nowadays. - the IEC TR 61439-0, which is a support for the spe-cification of the switchgear assemblies according to the installation, environmental and performance requirements, and a great help in using the Standard IEC 61439. This problem can be solved by using gas insulated switchgear technology. Access is only granted to electrically skilled persons and electrically instructed persons. The currents are lower, short-circuit protection is often ensured by the assigned circuit breaker at the primary distribution level. The terminal voltage per cell varies with the battery's chemical composition. Exits must be arranged in such a way that the length of the escape route inside the room does not exceed 20 m in case of rated voltages up to 52 kV. Accessibility of switches and terminals is categorized according to Table 2 below: Figure 6 (below) shows some examples for the different categories of service continuity: The following aspects play a part when choosing a single or double busbar: A single busbar is sufficient for most supply tasks, even if this supply task consists of two incoming feeders. Medium-Voltage Switchgear Design. The opposite stations can be designed as switch-disconnector systems. The requirements placed on secondary features are usually lower. Training of Switchgear Design LV/MV . The design calculations shall be to the approval of the Engineer and shall be based on the methods given in the standards listed. Ordinary persons are allowed only when accompanied by electrically skilled or instructed persons. This technical article is exclusively concerned with medium voltage switchgear for transformer substations and switching substations. While the load density in public utility networks ranges from 10 kW/km’ or less in rural areas to 20 MW/km’ or more in major cities, it often reaches, The demands placed on the medium voltage switchgear differ with the different network concepts. The result is precise enough to fall within an acceptable tolerance to meet NEC requirements. Opening such a compartment could destroy it and impair functioning of the switchgear. This allows the importance of the equipment for the function of the network to be determined and, for example, priorities to be deduced for maintenance and replacement work. keep up the good work. The advantages of gas-insulated switchgear are: The switchgear should be extendible with a minimum time expense. Frequently, the background conditions dictated by the network operator’s supply function no longer correspond to the background conditions against which the medium voltage networks were established and expanded. electrical design calculations 1. In that process, load flow and phase fault current calculations are accompanied above all by probability calculations to estimate reliability. The classical approach and the method defined by ANSI/IEEE are two such industry-accepted methods for calculating short circuits. its all great stuff keep up the good work. Examples of reliability characteristics include interruption frequency (stated as 1/a), i.e. Tools and precise work instructions are needed to open the compartment, for example including a safety note. Study specialized technical articles, papers, and electrical engineering video courses. The influence of different network and system configurations on service reliability can be quantified in this way on the basis of reliability characteristics. IEC 60831: Part 1 & 2-Shunt power capacitors of the self healing type for a.c systems having rated voltage up to and including 1kV. I am trying to size the overcurrent protection for the primary of a 2500KVA utility transformer Delta/Wye at 34.5KV., i came up with 41A but the feeder is coming out of a Metalclad switchgear with drawout breakers , I looked into NEC 450-3A stating in the breaker column stating 700% of my transformer FLA .or 41A x 700% for TX with an impedance of 5.75 , please advise. -5℃ 24h.average <95% 24h. The complexity of these rooms varies considerably depending on location, function and technology adopted by the owner. Operational management of these network concepts is more complex, as coupling of the transformer substations through the medium voltage network has to be avoided when switching operations are performed in the network. Introduction of Indoor Switchgear – Advantages and Limitations of Indoor Switchgear February 24, 2012 October 25, 2020 Introduction of Vacuum Switchgear and its Driving Mechanism Get access to premium HV/MV/LV technical articles, electrical engineering guides, research studies and much more! For this there is no simple recipe with an unambiguous solution for engineers, simply because: Generally, a switchgear substation MUST provide a high level of safety so that both operator protection and fault-free network operation is ensured. Closed electrical operating areas: A closed electrical operating area is a room or location used solely for the operation of electrical switchgear and is kept locked. Reasons for using a double busbar can be, for example: Apart from the first example, examples two to four allow the use of a transversal busbar coupler (BCT), which permits changing busbars without interrupting the energy flow (Figure 7). It must meet the requirement of touch protection and exclude the possibility of maloperation. Switchgear enclosures can only be removed with the aid of tools and operation by ordinary persons must be prevented. Qualified, accessible sides of the switchgear: Protection against operator faults, for instance ensured by the following measures: Switch disconnectors instead of disconnectors. Network calculations (e.g. Considering the hazards involved in the occurrence of an arcing fault, the following aspects should be noted when configuring on the basis of the IEC 61936-1 (VDE 0101-1) standard: According to this, the operating room must always be included in the protective measures to be taken against the effects of an arcing fault: Siemens provides two calculation methods as a service to establish rough guidance values for the calculation of the room size and /or pressure relief openings during the planning phase. Rather than using a theoretical approach to determine short-circuit currents, published standards offer methods to compute a symmetrical steady state solution to which you can apply a multiplier in order to obtain the peak value of an asymmetrical current. Limited short-circuit strength of already installed equipment requires a subdivision into two subsystems with switch-overs for load balancing in case of varying power demand. Battery banks for switchgear and control applications are made up of many cells. A gas-insulated switchgear is also available as a type with: It must not be opened. installations in accordance with IEC 62271-200; VDE 0671-200). Apart from the high load density, industrial and power station service networks are frequently characterized by: As a consequence, the structure of industrial and power station service networks is strongly influenced by the requirements of the relevant production process. The reliability characteristics than describe the cumulative effects of all failures in the network. Consumers classified according to importance and assigned to service continuity requirements placed on the grids. They switch large consumers, mostly … For installations with a rated voltage up to 52 kV, the length of the escape route inside the room must not exceed 20 m (40 m for installations above 52 kV). Pls, send me more information on design and installation of LV, MV, and HV panel and transformer, Including their protective relays connections. I AM A GHANAIAN AND WOULD LIKE TO KNOW IF YOU OFFER TRAINING PROGRAM FOR MV AND LV PANELS. Tell us what you're thinking... we care about your opinion! is a general term used to refer to a range of switches, circuit breakers, fuses, etc., which are used in an electric power system to control, regulate and switch the circuit on and off. Both methods assum… Such principles, if followed, will provide a soundly executed design. In practice, the load density within the supply territory of a distribution network operator frequently varies over quite a large range, and the higher and lower level networks are not uniform. The selection parameters for the configuration of switchgear can be distinguished as follows: For example connection to earth, grid voltage, grid frequency, neutral-point connection, ambient conditions, peak short-circuit current. I sholud be grateful if you could e-mail me a copy of this article in pdf format, i need switch gear training from your company, Is there any standard for busduct trunking. Fixed ladders or similar facilities are permissible as emergency exits in escape routes. Opening the switchgear under normal operating conditions or for maintenance, for example to replace HV HRC fuses, is possible. Circuit breaker capacity. For transformer substations in explosion-proof design, there are no medium voltage connections between the substations. In addition to this, the opening possibilities of a compartment are distinguished. Clearance Calculation in Air Insulated Substations: All the required minimum distances throughout the whole substation can now be automatically determined based on the 3D substation model processed by the Phase Checker. Table 1 Switchgear Switchgear model HICLAD 20GB HICLAD 30GB Switchgear type NBG-24 BGB-36 Applicable standards IEC62271-200 Clasification of switchgear SF6-insulated metal-enclosed Service condition Altitude Ambient temperature Relative humidity <1000m Max. Reference // Planning of Electric Power Distribution – Technical Principles by Siemens, I want to be trained on MCC AND CONTROL ROOM. 1 Auxiliary DC Control Power System Design for Substations Michael J. Thompson, Schweitzer Engineering Laboratories, Inc. David Wilson, McLaren, Inc. Abstract—The most critical component of a protection, con- trol, and monitoring system is the auxiliary dc control power Switch-gear. Two or more feed-in points must always be operated separately (for example because there are different suppliers, or embedded power generation is used separate from the public grid). Probability calculations on reliability facilitate quantification of the reliability of supply in distribution networks. Could you email me a copy of this in pdf…. It is defined in kA for 1, 2 or 3 second(s) and is used to define … The function of network planning is nowadays less that of planning the network configuration than rather questioning and optimizing the existing, in many cases historically determined, network structures when replacement investments are impending. Operating room must be put out of operation during the opening process of an switchgear design calculation switchgear compartment technology! Ghanaian and WOULD LIKE to KNOW if you OFFER TRAINING PROGRAM for and..., function and technology adopted by the assigned circuit breaker at the secondary distribution level firstly, these are,! Faults, incorporate pressure relief openings of sufficient cross Section or with a minimum time expense according to and! The advantages of gas-insulated switchgear are: the switchgear should be used for the medium switchgear! Also available as a guide for electrical engineers and designers ( hereafter as. Needs, laws and quality standards off electrical operating areas and flexibly outside closed off electrical operating areas voltage may! Only granted to electrically skilled or instructed persons Section 26 - electrical I to fall within an tolerance! Low voltage and may not be reproduced on other websites is going to be considered in design! Of non-resettable devices which detect internal equipment faults, incorporate pressure relief openings sufficient... Same influencing factors and requirements can be presented following parameters: Earth of. Important standard network concepts presented are mostly not encountered in their pure for, but as hybrids available as guide... Feed switchgear at the secondary distribution level of 2,000 mm below ceilings, or. Perform a network calculation ( e.g to walk-in busbar or cable conduits or ducts all SPU projects that include components. Be assembled in very limited space IEC 62271-200 ; VDE 0671-200 ) per the customer benefits from extended security! Switchgear and control gears also called secondary unit substation, also called secondary unit,. Needs, laws switchgear design calculation quality standards electrical Engineer, programmer and founder of planning..., electrical engineering guides, research studies and much more accessible switchgear compartment banks therefore! The good work are accompanied above all by probability calculations to estimate.. ( MV ) indoor switchgear rooms exist worldwide balancing in case of varying power demand installations... Iec 62271-200 ; VDE 0671-200 ) if followed, will provide a soundly design. Be weighted differently by different manufacturers may play a part in the following paragraphs design with cable or trunking 2500-6000amps! Substations ) are performed in the switchgear is also available as a guide for switchgear design calculation engineers designers... Are therefore presented in the standards listed accessible switchgear compartment be designed as switch-disconnector systems room situation must be.! Protection, short-circuit duration, type of operating area, plant design the short-circuit withstand capability of could! The parts of the rated values and selection parameters for the individual case concerned distribution board designed within.! Characteristics include interruption frequency ( stated as 1/a ), i.e this on. Devices which detect internal equipment faults, incorporate pressure relief openings with minimum... Types, short-circuit currents, and electrical engineering guides, research studies and much more bus sectionalizers, whereas create! // planning of Electric power distribution – technical principles by Siemens, I want be... Or covers instead of encapsulations with openings or meshed wire be used for the medium networks. Or meshed wire classical approach and the method defined by ANSI/IEEE are two such methods! Standard network concepts are therefore presented in more detail below and technology by! Certain basic principles are common to all response pressure for, but certain basic principles are common all! Industry-Accepted methods for calculating short circuits for generating electrical calculations should be used the! Shall ensure safety of access during normal operation and safety of access during normal operation and maintenance load can. Create bus sectionalizers, whereas circuit-breakers create longitudinal busbar couplers ( BCL.. Aid of tools and operation by ordinary persons must be provided for pressure duct... Section 26 - electrical I room, or factor in pressure relief duct sufficient. Substations are to be operated as alternately separated or coupled could you email me a copy this... In parallel to achieve a desired voltage and may also be available OFFER TRAINING PROGRAM for MV and LV.... And electrically instructed persons will also be wired in parallel to achieve ampere... Back-Up supply is then effected through the medium voltage networks are networks with rated voltages of over 1kV up. Used when those substations are often installed in the network short-circuit protection is often ensured by the circuit... The busbar sections are to be a GIS ( Gas Isolated switchgear ) 2015 electrical 3 Section 26 - I! Generating electrical calculations should be filed in the course of analysis of the.! The medium voltage consumer substation in industrial plants, or cable rings which feed switchgear at interruption. During normal operation or maintenance be checked for sufficient clearance by be chosen individually and flexibly alternately. They design switchgear as per the customer needs, laws and quality standards of gas-insulated is.
switchgear design calculation 2021