Maintenance of electrical switchgear ms28, tl4 11 chapter 1 introduction 110 purpose 111 scope this handbook contains information on safety practices and environmental considerations when working on switchgear, descriptions of typical classes of switchgear, and preventive and corrective maintenance guidelines for switchgear. Relay classification, principle of different types of electromagnetic relay. Numerical relays protection and control products for power. A big difference between conventional electromechanical and static relays is how the relays are wired. Onsite prodiag mv relay diagnostic of medium voltage protection relays condition and configuration settings improve protection of people and goods mitigate shutdown costs optimize total cost of device ownership onsite prodiag mv relay objective accurate tripping time operation in accordance with medium voltage relay. The connection of an electrical installation to a mv utility distribution network. For industrial applications, a transformer and switchgear lineup may be combined in one housing, called a unitized substation uss. Medium voltage products technical guide protection. Features and importance of switchgear device relays in. In this article, selection of relay for incoming and outgoing feeders for lv switchgears motor control centers and mv switchgear up to 33kv has been discussed.
Electromechanical and static relays have fixed wiring and the setting is. The switchgear on the lowvoltage side of the transformers may be located in a building, with mediumvoltage circuit breakers for distribution circuits, along with metering, control, and protection equipment. If a pickup of more than 160a or less than 40a is required, it would be necessary to select a ct with a different ratio or, in some cases, a different relay with higher or lower tap settings. No damage evident inspect panels and doors for proper fit and alignment equipment labels permanently affixed panel is clean and clear of dust or dirt. Pick up current current setting plug setting multiplier. I had a question regarding what is the best practice to set the instantaneous setting on a relay which feeds a downstream mv switchgear lineup.
From 3 kv to 36 kv switchgear system is categorized as medium voltage switchgear or mv switchgear. The sf6free medium voltage switchgear ecosc, rated to 24 kv rated. Medium voltage technical guide electrical engineering portal. Driescher medium voltage switchgear ecosc bbc cellpack.
Switchgear and protective devices 310 modulei 10 hours protective devices. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Manual installation commissioning environment and recycling. When any fault occurs on any part of the system, it must be detected and the unhealthy part of the system must be disconnected from the healthy. Understand and explain the differences between mv class e2 controllers mcc and mv mc switchgear 2. Digital protection relays and power metering see page f1. The term medium voltage is commonly used for distribution systems with voltages above 1 kv and generally applied up to and including 52 kv1. Tests prescribed will evaluate the performance of the switchgear, and shall comply with this specification. At the end of this presentation you will be able to. Abbs mv products tradition dates back to the 1920s with the introduction of the first mv switchgear manufactured by. Thoroughly test the switchgear at the factory with the circuit breakers in the connected position in their cubicles. The protection relay setting must be calculated to give the plant. Ca285001en pst padmounted switchgear with ist control. They may metal enclosed indoor type switchgear, metal enclosed outdoor type switchgear, outdoor type switchgear without metal enclosure, etc.
For technical and economic reasons, the service voltage of medium voltage distribution networks rarely exceeds 36 kv. So sooner or later some failure can occur on any part of the system. Protection equipment works in conjunction with switchgear. Siemens mediumvoltage switchgear and breakers, siemens is committed to supporting you with qualified parts and factory trained field service support throughout your products life cycle. Relay aux iliary devices such as ex ternal resis tors, metros ils, etc. Selection of relay for incoming and outgoing feeders for mv. Medium voltage products technical guide protection criteria. Name the two common protection relays used on medium voltage breakers 3. Commission testing methods for protection systems mipsycon. This relay detects current above normal settings and operates when the current. Philosophy of protection, nature, causes and consequences of faults, zone of protection, requirements of a protective scheme, basic terminology components of protection scheme. Jan 02, 2019 from 3 kv to 36 kv switchgear system is categorized as medium voltage switchgear or mv switchgear. Siemens has a comprehensive database of drawings and manufacturing capabilities to fabricate a direct match. The interruption medium of this switchgear may be insulating oil, sf.
The time dials on the relays are set at zero in the factory so the relay contacts will be closed during shipping. Instantaneous setting on a relay upstream of mv switchgear. Name the two common protection relays used on medium voltage breakers. Fast powerup of the vip 300 also provides immediate. The relay provides for a wide range of protection settings for most applications.
Pst padmounted switchgear with ist control general eaton provides both automatic load transfer and feeder fault and overcurrent protection in a single padmounted switchgear unit with its cooper power series pst padmounted source transfer switchgear package, a selfcontained load transfer device. Operation, maintenance, and field test procedures for. Therefore the antipump relay prevents the spring from doing the following. Pdf mv switchgear protection relays inspection and test procedure find, read and cite all the research you need on. Paralleling is the operation in which multiple power sources, usually two or more generators, are synchronized and then connected to a common bus. Tests prescribed will evaluate the performance of the. Ms28 handbook maintenance of electrical switchgear tl4.
Mv switchgear to iec 62271200 fully enclosed in metal enclosure and having some current carrying capacity partition class i or m classification based on electrical field presence in safe access compartment partition class pm personnel comfort during maintenance all partitions and shutters of safe access compartment shall be metallic. With over years expertise, brush switchgear has a reputation for innovation, first class product performance and delivering high service standards to our customers in the major utilities, industrial. That means the moving parts of the relay take total 3 seconds to travel 100 % traveling distance. Jan 30, 2014 mv switchgear to iec 62271200 fully enclosed in metal enclosure and having some current carrying capacity partition class i or m classification based on electrical field presence in safe access compartment partition class pm personnel comfort during maintenance all partitions and shutters of safe access compartment shall be metallic. Mediumvoltage switchgear type nxplus c wind fixedmounted circuitbreaker switchgear up to 36kv, extendable single busbar, metalenclosed, gasinsulated mediumvoltage switchgear installation and operating instructions order no 8029074. Authors paul price, nate myers, jim dehaan bureau of reclamation hydropower technical services group denver, colorado 5d. Selection of the protection system and relays depends on and is correlated with the plant characteristics, type of industrial process and its service continuity requirements, with the status of the neutral, characteristics of the machines, levels and duration of the fault currents, etc. A power system consisting of generators, transformers, transmission and distribution lines. Fieldselectable fuse or relay curves and trip settings are available.
Older types using a manual or dependent manual closing mechanism are. Relay is a sensing device which senses abnormal voltage and current conditions in power system and sends signal to circuit breaker to remove faulty part from rest of the power system. When using the residual relays an allowance is to be made for the possible inaccuracy among the ct circuits due to unequal highmagnitude transformer inrush currents. Dvcas switchgear can go through doors that are a minimum of 23. The idmt characteristics employed for both the overcurrent and earth fault elements can be easily adjusted to provide discrimination with upstream mv and downstream lv protective devices. Medium voltage switchgear construction checklist page 3 of 6 version 0206 inspect for physical, electrical and mechanical condition of equipment and cabinet. The contacts of this relay prevent uncontrolled discharging of the closing spring, if the closing signal remains complete up to the breaker.
No damage evident inspect panels and doors for proper fit and alignment equipment labels permanently affixed panel is. This paper covers general safe operations on medium voltage equipment and looks at the aspects of switching, isolating, testing and earthing, as well as various types of medium voltage testers and their usage. The pickup settings would range from a primary current of 40a the 4a tap to 160a the 16a tap. Technical guide protection criteria for medium voltage. An rmu is a specific type of switchgear comprising a pair of switches for a ring circuit to loop in and out, plus a switchfuse or breaker for the tapoff feeding the load, all integrated into a single unit. It is important when operating on medium voltage equipment that we follow the safety rules and operating regulations in order to be safe. Relay acceptance testing owner preferences verify 100% of all included analog and digital io even if not all the io are used load relay settings digital relays setting files loaded into relays vendor specific software tools verify by comparing relay to setting file should be no differences. Medium voltage switchgear shall be thoroughly tested at the factory to assure that there are no electrical or mechanical defects. The molded vacuum interrupters are provided with selfpowered electronic control packages, requiring no batteries or external power. Paralleling switchgear by maurice dmello 1 september 2008 paralleling switchgear by maurice dmello, p. The medium voltage switchgear ax1 is not just a medium voltage cubicle, but also a complete switchgear systeminstallation. Numerical relays are based on the use of microprocessors.
This can generally be accomplished by setting the 50n at four. First line of defense is provide by the back up relaying equipment. Sep 17, 20 relay is a sensing device which senses abnormal voltage and current conditions in power system and sends signal to circuit breaker to remove faulty part from rest of the power system. Mediumvoltage switchgear is usually installed inside the wind generators, so their design must allow enough access through the door in case replacement is needed. Residual relays 5051n are often used to detect ground currents on solidly grounded or lrg medium voltage systems.
Abbs mv products tradition dates back to the 1920s with the introduction of the first mv switchgear manufactured by brown boveri. Tests shall be conducted as per ul, ansi and csa standards. If the circuit remains complete, the closing spring would discharge under the wrong conditions, this is called pumping. The ground bus in the switchgear is assembled in sections. From a definition point of view ax1 is a primary encapsulated and air insulated switchgear. Relay and switchgear protection linkedin slideshare. Selection of proper relay is one of the most important stages to have a reliable network. An overview mv network basic definitions circuit breaker switchgear control gear fault basic functions disconnection control protection.
This means that all high voltage parts are housed in the encapsulated main circuit enclosure and are inaccessible from the outside. Rm6 documents and downloads schneider electric global. Switchgear is a fairly generic term for equipment which incorporates switches or circuit breakers. Describe the basic power components of a mv class e2 motor. Mediumvoltage mv products play a key role in the distribution part of the power value chain, facilitating the last mile connect that brings electricity to billions of users around the world. May, 2014 i had a question regarding what is the best practice to set the instantaneous setting on a relay which feeds a downstream mv switchgear lineup. Thoroughly test the switchgear at the factory with the circuit breakers in. Topics include mediumvoltage networks, power transformers, switchgear, mv lv substations, service conditions, shortcircuit, voltage drop, dielectric withstand, accessibility, service continuity, parallel operation, natural cooling and corrosion, general information on protection, control and monitoring, smart grid and eco design. Fist 38, operation, maintenance, and field test procedures for protective relays and associated circuits 5a.
Components of the virtual main arc flash mitigation system. Uninterruptible power supply ups industrial automation and control. Topics include mediumvoltage networks, power transformers, switchgear, mvlv substations, service conditions, shortcircuit, voltage drop, dielectric withstand, accessibility, service continuity, parallel operation, natural cooling and corrosion, general information on protection, control and monitoring, smart grid and eco design. Acbs and oil circuit breaker ocbs at medium voltage levels. By medium voltage, we mean a voltage range of volts to 38 kv. A digital relay and overcurrent sensing is added to the lowvoltage side of the service transformer and is designed to trip an existing upstream fault breaking device, often a mediumvoltage circuit breaker or other vacuum interrupter.