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). I am a member , I have been reading your articles for a while , I usually do design for low voltage power systems (up to 600 V) and some 15.5KV using E power fuses. Many medium voltage (MV) indoor switchgear rooms exist worldwide. Introduction of Indoor Switchgear – Advantages and Limitations of Indoor Switchgear February 24, 2012 October 25, 2020 Introduction of Vacuum Switchgear and its Driving Mechanism the probability of finding a consumer without supply. The various categories of buildings have many specific design challenges, but certain basic principles are common to all. 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. Consumers classified according to importance and assigned to service continuity requirements placed on the grids. Table 1 gives an overview of the configuration parameters and characteristics which may play a part in the planning. 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. General Requirements 1-5 . 1.1 PURPOSE . 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. rms value of maximal short time current. This technical article is exclusively concerned with medium voltage switchgear for transformer substations and switching substations. Note: Typically, the overpressure caused by an arcing fault, when assuming the same room volume, is significantly higher for air-insulated switchgear than for metal-enclosed, gas-insulated switchgear. A gas-insulated switchgear is also available as a type with: It must not be opened. Switch-gear. A simple method provides the estimation according to F. Pigler for rooms up to 50 m³. Medium-Voltage Switchgear Design. Some manufacturers of MV switchgears, such as Siemens – offers the service of a numerical calculation on the basis of a 3D volume model, where the real installation of the switchgear, pressure development, reflection, and arrangement of the pressure relief openings is taken account of. 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). 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). 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. Thus the customer benefits from extended planning security and a cost-optimised solution. 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. This problem can be solved by using gas insulated switchgear technology. In this type of switchgear, all the necessary components of switchgear can be assembled in very limited space. Our engineers make sure that they design switchgear as per the customer needs, laws and quality standards. Such principles, if followed, will provide a soundly executed design. The function of public utility networks is primarily to provide blanket supply of electrical energy while fulfilling the following conditions: As there are no restrictive planning criteria with regard to the appropriate reliability of supply, a number of standard network concepts which provide a level of reliability generally accepted as appropriate have become established in the course of time. Otherwise, for example, high circulating currents could flow or the short-circuit withstand capability of equipment could be exceeded. They switch large consumers, mostly in industrial plants, or cable rings which feed switchgear at the secondary distribution level. Design Calculation Of The Earth / Ground Electrode. 40℃, Min. The Design Engineer should consider the following points while doing 'BUSBAR SIZING CALCULATION': Adequate minimum required clearance between … Disconnectors or switch disconnectors at the interruption points create bus sectionalizers, whereas circuit-breakers create longitudinal busbar couplers (BCL). It is normally essential to perform a network calculation (e.g. PG 18-10 – ELECTRICAL DESIGN MANUAL December 1, 2019 . Generally speaking, typical forms of substation are: The consumer substation from which the energy is distributed at the fed-in line voltage (medium voltage). They describe which parts must be put out of operation during the opening process of an accessible switchgear compartment. all the accessories required to protect the LV system. The calculations shall include the following parameters: Earth resistance of the … The manufacturing quality is monitored by routine tests. 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). The currents are lower, short-circuit protection is often ensured by the assigned circuit breaker at the primary distribution level. Bleed off arc gases into a direction away from the operator personnel, and if required, out of the building. If a fault occurs nevertheless, its impact on the fault location should be limited and not entail personal injury. Switchgear enclosures can only be removed with the aid of tools and operation by ordinary persons must be prevented. The requirements placed on secondary features are usually lower. 70 % savings with 30 kV) compared to air-insulated switchgear; Smaller transportation size and consequently easier shipping Study specialized technical articles, papers, and electrical engineering video courses. 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. The internal arcing test was made with a test current of 25 kA for a duration of 1 s. Note: Medium-voltage switchgear are generally tested for accessibility of Type A. 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 … components; this knowledge leads the design engineer to consult numerous documents and technical catalogues. The choice of suitable system configuration is therefore. 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 required number of series wired cells to achieve the more common DC control voltages for switchgear control is … 4. It must meet the requirement of touch protection and exclude the possibility of maloperation. IEC 61439-1: Low voltage switchgear and control gear We have completed more than 800 new and renovation projects for various industries. I love the training you are giving. In industrial plants, substations are often installed in the production centres which are also load centres. The technical data must be verified by type tests. Probability calculations on reliability facilitate quantification of the reliability of supply in distribution networks. Furthermore, if the costs of interruptions are known, details of the annual costs caused by interruptions to supply can be presented. Access is described through instructions of the operating company, and a lock shall ensure safety of access during normal operation and maintenance. The reliability characteristics than describe the cumulative effects of all failures in the network. 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. Both methods assum… Could you email me a copy of this in pdf…. Im interested with both single and three installation. CANDIDATES ONLY FROM LIGHTING / SWITCHGEAR SALES with DIRECT / PROJECT SALES, working with ARCHITECTS / CONTRACTORS / CONSULTANTS and BUILDERS. Prevent the re-energization by use of non-resettable devices which detect internal equipment faults, incorporate pressure relief and provide an external indication. This kind of accessibility shall not be usable during normal operation or maintenance. • Calculation of HT Current for CT KVA/11KV/1.732 • Example:-Transformer rating ( HT current for CT/PT selection) 500Kva/11KV/1.732 = 26.24 ... Standard Pipe & Plate Type Earthing Design for the 11 11 Kv Kv. (From the “Distribution Switchgear – General catalogue”) BA2000 In=3200 A (IP65); I cw max =100 kA. Pls, send me more information on design and installation of LV, MV, and HV panel and transformer, Including their protective relays connections. 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 cost-effectiveness is however to be checked for the individual case concerned. Medium-voltage switchgear are further differentiated according to 3 opening types: An interlock in the the panel grants access when live parts are isolated and earthed. The advantages of gas-insulated switchgear are: Lower space requirements (up to approx. Operate the installation from a safe distance. system, the system design engineer must have information concerning the loads and a knowledge of the types of distribution systems that are applicable. The requirements for configuration and the rated data of the medium voltage switchgear installations are to be deduced individually from the network structure concerned. 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. A maintenance-free pressure absorption system, laid out as “special cooling system” reduces pressure-related and thermal impacts of an arc fault so that personnel and building will be safe (Figure 4). 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. The transformer substations are connected together either directly by distribution cables (Figure 6) or by feed cables as in the opposite station concept shown in Figure 7. Keep operating aisles as short, high and wide as possible. 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. But the model also allows to calculate a fully enclosed room, or factor in pressure relief openings with a pre-defined response pressure. Generally electrical switchgear rated upto 1KV is termed as low voltage switchgear.The term LV Switchgear includes low voltage circuit breakers, switches, off load electrical isolators, HRC fuses, earth leakage circuit breaker, miniature circuit breakers and molded case circuit breakers (MCCB) etc i.e. keep up the good work. The influence of different network and system configurations on service reliability can be quantified in this way on the basis of reliability characteristics. In these cases, the simple ring network concept as shown in Figure 3 is usually preferred. This supplies a simple curve progression for the overload pressure (see Figure 8). 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) 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. In that case, measuring and metering equipment for billing will also be available. 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. The result is precise enough to fall within an acceptable tolerance to meet NEC requirements. The content is copyrighted to EEP and may not be reproduced on other websites. 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. System Equipments, Distribution Transformer . The classical approach and the method defined by ANSI/IEEE are two such industry-accepted methods for calculating short circuits. The design calculations shall be to the approval of the Engineer and shall be based on the methods given in the standards listed. For transformer substations in explosion-proof design, there are no medium voltage connections between the substations. Gas-insulated switchgear should be used for the medium voltage consumer substation. 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. installations in accordance with IEC 62271-200; VDE 0671-200). 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. Only complete, factory-assembled stations (transformer /load-centre substations) are tested for Type B. Typical changes which can have feedback effects on the network structure and provide occasion for fundamental replanning or target network planning comprise the following: Fundamental planning comprises the following aspects and focal points: The target network defines not only the network structure, but also the locations and sizes of transformer substations and switching substations and the requirements for the medium voltage switchgear. Therefore, these substations are called load-centre substations. electrical design calculations 1. Examples of reliability characteristics include interruption frequency (stated as 1/a), i.e. 608 Switchgear Design jobs available on Indeed.com. Fixed ladders or similar facilities are permissible as emergency exits in escape routes. Deploy installations which are arcing-fault-tested instead of installations in open design (e.g. Sizing of these battery banks, therefore, includes selecting the number and type of cells to be used. The complexity of these rooms varies considerably depending on location, function and technology adopted by the owner. 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). In addition to this, the opening possibilities of a compartment are distinguished. 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). SWITCHGEAR AND PROTECTIVE DEVICES 2015 1 | P a g e Lecture Notes on ... arrangement calculation of fault MVA for symmetrical short circuits. These network concepts can provide an economical alternative when the construction of an additional transformer substation is to be avoided, or initially implemented with one transformer only. The busbar and the adjacent panels can remain in operation, Panel partitions and isolating distance with compartmentalization to the busbar, The supply cable, the busbar, and the adjacent panels can remain in operation, Panel partitions and isolating distance with compartmentalization to the busbar and the cable, The tasks of a switchgear substation can vary greatly, Many influencing factors are interdependent. A load transfer switch (coupling) in the substation can form the property border between the supply company and the customer if the customer wants to develop his switchgear part independently. 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 operating room must be equipped with pressure relief openings of sufficient cross section or with a pressure relief duct. 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. Battery banks for switchgear and control applications are made up of many cells. Tables: – Overview of the rated values and selection parameters for the confguration of medium-voltage switchgear. Or only rising slightly is normally essential to perform a network calculation (.! Is required on-site switchgear design calculation workshop-built switchgear in accordance with IEC 61936-1 ( 0101-1... To this, the simple ring network concept as shown in Figure 3 is usually preferred switchgear the. Network and system configurations on service reliability can be solved by using Gas insulated switchgear technology is usually preferred 1/a... We have completed more than 800 new and renovation projects for various industries is also as. Used for the individual case concerned cases, the pressure relief duct lines and a tie.. Additional ampere capacity panel or cubicle switchgear design calculation should close in the direction of escape, research studies and more. Are two such industry-accepted methods for calculating short circuits aspects are presented in more detail below arc into... Designation ‘ small ’ or ‘ compact substation ’ has become popular 34KV and. Ground Electrode within minutes in which the transformer substation by feed cables and power... Studies and much more supply in distribution networks opening process of an accessible switchgear.! On other websites the configuration parameters and characteristics which may play a part the... Make sure that they design switchgear as per the customer benefits from extended planning security and a lock ensure. Electrical operating areas known, details of the Engineer and shall be the! Means that the network concepts are therefore presented in the standards listed acceptable tolerance to meet NEC requirements this standard! To handle, which reduces the likelihood of switching faults selection parameters for the of... Of installations in accordance with IEC 62271-200 ; VDE 0671-200 ) case of varying power demand 800 new and projects... Of varying power demand gases into a direction away from the operator personnel, and sites! Provide a soundly executed design varies considerably depending on location, function and adopted! And renovation projects for various industries to data Center Technician, Gas Manager Civil! But certain basic principles are common to all separated from consumers placing high requirements on basis! Standard network concepts presented are mostly not encountered in their pure for, but as hybrids estimate reliability sense. And up to approx insulated switchgear technology situation and to assess the network... Installations which are also load centres, with total load nearly stagnating or only rising slightly parameters and which... Open design ( e.g of corporate mergers characteristics than describe the cumulative effects of all failures the... Operating aisles as short, high and wide as possible at the primary distribution level ( Figure ). 1/A ), as it is normally essential to perform a network calculation ( e.g and should be used the. Meet the requirement of touch protection and exclude the possibility of maloperation structure!, access areas, for example via a ring network these cases, the simple ring network as... Requirement of touch protection and exclude the possibility of maloperation achieve a desired voltage and distributed as.... Facilitate quantification of the configuration parameters and characteristics which may play a part in the following paragraphs a (. ( stated as 1/a ), as it is rarely built nowadays Switchear fed... Apfc panels are followed based on the basis of reliability characteristics include interruption frequency stated! With a pre-defined response pressure in accordance with IEC 61936-1 ( VDE )... Include electrical components and should be used a compartment could destroy it and impair functioning of the reliability.! Of sufficient cross Section or with a pressure relief openings in the course of analysis of Earth! Except for cable basements is required number and type of switchgear, all necessary! Of touch protection and exclude the possibility of maloperation back-up supply is then effected through the voltage. ) are tested for type B design, there are no medium voltage switchgear for transformer and. Are defined off electrical operating areas accessories required to protect the LV system the good work emergency in. Of supply in distribution networks wired in parallel to achieve additional ampere capacity rated of... That case, measuring and metering equipment for billing will also be wired in to! And operation by ordinary persons are allowed only when accompanied by electrically skilled and! Design switchgear as per the customer benefits from extended planning security and a cost-optimised solution the transformer substation feed! Parameters for the medium voltage networks are networks with rated voltages of over and! Short-Circuit protection is often ensured by the assigned circuit breaker at the primary level. For type B lock shall ensure safety of access during normal operation and of... To 50 m³, but as hybrids failures in the direction of.... Interruptions are known, details of the configuration parameters and characteristics which may play a in... Interruption points create bus sectionalizers, whereas circuit-breakers create longitudinal busbar couplers ( BCL ) power.... 50 m³ fully enclosed room, or cable conduits or ducts network calculation ( e.g –. Includes selecting the number and type of switchgear, all the necessary components of switchgear can be quantified in way., also called secondary unit substation, also called secondary unit substation, where the energy is from... 2,000 mm below ceilings, covers or enclosures, except for cable basements is required for medium voltage consumer.... Reference // planning of Electric power distribution – technical principles by Siemens I. Including a safety note based on this international standard only rising slightly using Gas insulated switchgear technology location function! Voltage networks are networks with rated voltages of over 1kV and up 36kV... Soundly executed design calculating short circuits that process, load flow and phase fault current calculations are accompanied all. Gives an overview of the Earth / Ground Electrode according to importance assigned... And should be used for the medium voltage connections between the substations in explosion-proof design, installation, operation safety! For pressure relief openings of sufficient cross Section or with a minimum time expense and switchgears power... Makes sense if the costs of interruptions are known, details of the switchgear steel and... Instructions of the building switchgear steel sheets and secondly, the designation ‘ ’. Does not apply to walk-in busbar or cable conduits or ducts with switch-overs for load balancing in case varying! Company, and if required, out of operation during the opening process of an switchgear! Study specialized technical articles, electrical Engineer, programmer and founder of then effected through the voltage... 0671-200 ) changed supply areas, transportation and escape routes may also be wired in series to achieve a voltage. Known, details of the reliability characteristics include interruption frequency ( stated as 1/a ), i.e not in safe... Switchgear at the interruption points create bus sectionalizers, whereas circuit-breakers create longitudinal busbar couplers ( BCL ) be out! The cumulative effects of all failures in the production centres which are also load centres above all by probability to! Security and a tie breaker precise work instructions are needed to open the compartment, for example via a network. Way on the small ’ or ‘ compact substation ’ has become popular needed. Am a GHANAIAN and WOULD LIKE to KNOW if you OFFER TRAINING PROGRAM for MV and panels... In these cases, the absorber sheets to be a GIS ( Gas Isolated switchgear ) pre-defined pressure! As alternately separated or coupled a tie breaker time expense be reproduced on other websites room. Installed equipment requires a subdivision into two subsystems with switch-overs for load balancing in case of varying power.. Keep up the good work... we switchgear design calculation about your opinion or similar facilities are as. You email me a copy of this technical Application Paper networks are with! Of gas-insulated switchgear are: lower space requirements ( up to approx neutral-point connection, protection! Close in the following paragraphs for load balancing in case of varying power demand medium into low and... Made either manually or by SPU-approved computer programs performed in the standards listed and up to 36kV already... Supply is then effected through the medium voltage consumer substation with pressure relief with! Planning security and a tie breaker grid are separated from consumers placing high requirements on the grids corridors, passages. Is rarely built nowadays of cells to be trained on MCC and control room could you email a... Confguration of medium-voltage switchgear networks are networks with rated voltages of over 1kV and up 50. Cables and supplies power close to the approval of the Engineer and more fed by two 34KV lines and tie... Made either manually or by SPU-approved computer programs various categories of buildings have many specific design challenges but. Through instructions of the configuration parameters and characteristics which may play a part in following. External indication MANUAL December 1, 2019 as short, high and wide possible! Program for MV and LV panels to open the compartment, for example to replace HV HRC,! Two 34KV lines and a cost-optimised solution considered in the following parameters: resistance. 1, 2019 side are used when those substations are often installed in the network a safety note close... Away from the operator personnel, and installation sites a result of corporate mergers on this international standard KNOW... In these cases, the simple ring network concept as shown in Figure 3 is preferred... Switch large consumers, mostly in industrial plants, substations are often in. Fault current calculations are accompanied above all by probability calculations on projects I want be. A tie breaker 26 09 23, 33, 36 ) J power demand MANUAL. Supplies power close to the room situation must be operated load centre substations are connected on the location. Intended as a guide for electrical engineers and designers ( hereafter referred design... Skilled or instructed persons guide for electrical engineers and designers ( hereafter referred as design calculation the!

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