Relay and switchgear protection linkedin slideshare. Aug 24, 2017 switchgear is the combination of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment from the abnormal condition is called switchgear. As such switchgear can be a power fuse or a power breaker or a combinatio. Feb 26, 2017 in india, voltage less than or equal to v is termed as lv lt. Switchgear, electrical switchgear, medium voltage switch. It applies to enclosure of electrical equipments with a rated voltage of less then or equal to 72. A grid providing ventilation and a protective cover for a manhole opening. Mar 25, 2017 this video provides all the important concept of switchgear and protection of power system in detail and also provides some important points to remember for exams and interviews. Cts and pts and their applications in protection schemes. The top countries of suppliers are india, china, and india, from which the percentage of ht switchgear supply is 6%, 91%, and 6% respectively.
First line of defense is provide by the back up relaying equipment. Electrical control panel, ht panels, lt panels, capacitor. This subject provides the knowledge on switchgear and protection of various power system elements. This video provides all the important concept of switchgear and protection of power system in detail and also provides some important points to remember for exams and interviews. The apparatus used for switching, controlling and protecting the electrical circuits and equipment is known as switchgear. Ht switchgears manufacturer, lt switchgears supplier. Chander, power system protection and switchgear, wiley eastern ltd. Ht switchgear february 4, 2017 by tnsadmin ht switchgear lbs substation leave a comment key featurestechnical datadownload application one of the basic functions of switchgear is protection, which is interruption of shortcircuit and overload fault currents while maintaining service to. A tough and resilient sheath with excellent fire resisting qualities. Abb delivers state of the art technologies to italys most innovative data center. The function of a switchgear switchgear has to perform the functions of carrying, making and breaking the normal load current like a switch. 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. Philosophy of protection, nature, causes and consequences of faults, zone of.
Ht lt switchgear service written by administrator sunday, february 2011 14. Ms28 handbook maintenance of electrical switchgear tl4. Annual overhauling of htlt switchgears and htlt motors. Medium voltage products technical guide protection. Vcb panels are precisely designed following strict industry parameters and are appreciated for features like superior quality and cost effectiveness. This video provides all the important concept of switchgear and protection of power system in detail and also provides some important points to. A switchgear is a generic term which includes all the switching devices associated with power system protection. Annual overhauling of htlt switchgears and htlt motors of. If these conditions changes, then overall protection needs to be changed. So to protect the lines, generators, transformers and other electrical equipment from damage automatic protective devices or switchgear devices are required. Switchgear and protection electrical engineering mcq questions and answers home category electrical engineering mcq questions and answers switchgear and protection 1 in the following figure, which component ensures the safety of the line from damage. Switchgear, electrical switchgear, medium voltage switch gear. Switchgear and protection electrical engineering mcq. We have brought together the combined experience of.
A wide variety of ht switchgear options are available to you, there are 60 suppliers who sells ht switchgear on, mainly located in asia. Vacuum interrupters design applications and limitations. Complete protection against most forms of electrolytic and chemicalcorrosion. Ht switchgear february 4, 2017 by tnsadmin ht switchgear lbs substation leave a comment key featurestechnical datadownload application one of the basic functions of switchgear is protection, which is interruption of shortcircuit and overload fault currents while maintaining service to unaffected circuits.
Improved operational safety, continuity of service, greater convenience and operating cost have assumed a tremendous significance. External lighting protection l fire protection systems l comunication systems. System for ht lt connection hvpn supply go switch ht metering vcb. Voltage more than 650v but less than or equal to 33kv is mv mt. Abbs ecoefficient airplus technology delivered to norwegian smart grid. Jan 27, 2018 switchgear can be a device or equipment that is used to safely connect, operate, protect and disconnect an electrical circuit within set rated limits of voltage and current. The insulationresistance shall be taken with all the winding earthed, expect, the one being tested. Restricted earth fault and interturn fault protection, numerical problems % winding. Switchgear and protection electrical engineering mcq questions and answers. Voltage more than 33kv but less than or equal to 230kv is termed as hv ht. Sunil s rao, switchgear protection and power systems, khanna publishers, new delhi, 11 th edition reprint 3 rd edition, 2008 references. In other words systems used for switching, controlling and protecting the electrical power.
Ht switchboards hvx is the latest range of vacuum circuit breakers. When a fault occurs within the boundary of a particular zone, then the protection system responsible for the protection of the zone acts to isolate by tripping the circuit breakers every equipment within that zone from the rest of the system. To study different relays characteristics to understand the method of circuit breaking, arcing phenomena. Back up protection operates only when primary protection has failed. For industrial applications, a transformer and switchgear lineup may be combined in one housing, called a unitized substation uss.
Home category electrical engineering mcq questions and answers switchgear and protection. In india, voltage less than or equal to v is termed as lv lt. This transformer is normally used for earth fault protection for low and medium. The skid mounted substation shall be of modular construction housed in a single enclosure consisting of ht control panel with one number load break switch, one number vcb and all other metering and protection, one no 11kv415v dry type. Introduction of indoor switchgear advantages and limitations of indoor switchgear. 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.
Circuit breakers provide a manual means of energizing and deenergizing a. Copy of nit 02 pages instruction to bidders 03 pages general conditions of contract 01 book special conditions of contract 07 pages safety, health and environment guide lines for contractors 30 pages. Htlt switchgears, electrical products kabsa peth, pune. Technical guide protection criteria for medium voltage. Medium voltage products technical guide protection criteria. Ht vcb control panels medium voltage panels exporter. The ip code is a coding system to indicate protection index. Abb unveils abb ability digital switchgear for secondary distribution networks. Contents relay buchholz relay circuit breakers instrument transformer 3. Inspection, test and measurement procedures for lv and mv up. Download switchgear and protection auroras engineering college. Problem with over current relaying is that fault current depends upon ckt condition and generating capacity. It applies to enclosure of electrical equipments with a.
It refers to electrical equipment that regulates the flow of electricity within an electrical system. The enclosure exterior shall be painted with polyurethene paint powder coated and tropicalized to indian weather conditions. Fundamentals of electrical substations and switchgear. Electrical machines and power transmission engineering course educational objectives. These products are used to provide protection in the form of interruption of shortcircuit and overload fault currents, while maintaining service to unaffected circuits. Types of circuit breakers air blast, air break, oil, sf6 and vacuum circuit breakers. Low voltage switchgear or lv switchgear generally electrical switchgear rated upto 1 kv is termed as low voltage switchgear. A guide for ht and lt switchgear used in thermal power plant. Sep 17, 20 distance protection whenever overcurrent relay is not selective or circuit requirements change, then distance protection is preferred. A combination of disconnect switches and breakers used to isolate equipment in substations. Switchgear and protective devices 2015 3 p a g e syllabus switchgear and protective devices 310 modulei 10 hours protective devices. Each breaker shall be provided with an emergency manual trip, mechanical. Chander, power system protection and switchgear, wiley. It also includes all devices associated with control, metering and regulating of electrical power systems.
Inspection, test and measurement procedures for lv and mv. Switchgear can be a device or equipment that is used to safely connect, operate, protect and disconnect an electrical circuit within set rated limits of voltage and current. For a short time it can withstand maximum c and iso. Industrial switchgear, circuit breakers, switches havells india. It offers proven stateoftheart design to meet to specification for power switching devices in airinsulated switchgear upto 36 kv. Types of lighting arrestors are horn gap, expulsion type, gapless metal oxide type etc. Installed in clean, well ventilated or airconditioned locations, switchgear will require little routine maintenance. The switches, fuses, circuit breaker, isolator, relays, current and potential transformer, indicating instrument, lightning arresters and control panels are examples of the switchgear devices. Switchgear and protection we are all familiar with low voltage switches and rewirable fuses in our home. In other words systems used for switching, controlling and. The entire range of havells industrial switchgear include switches, circuit breakers and conventional devices that are designed and manufactured according to world class standards.
T s madhav rao, power system protection, tmh pulication 4. Rao, switch gear and protection, khanna publication. In an electric power system, switchgear is composed of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical. The protection index is the level of protection provided to by an enclosure against access to hazardous parts, the penetration of solid foreign bodies and of water. Abb ability digital switchgear solution ensures reliable power in helsinkis smart city district.
Mahesh engineering services, since 1974, is a professionally managed trading company involved in industrial electrical materials. In an electric power system, switchgear is the combination of electrical disconnect switches, fuses or circuit breakers used to control, protect. While checking the value, external line, cable and lighting arresters shall be isolated from the h. Thus switchgear can be taken as a general term covering a wide range of equipment concerned with the switching, protection, and control of various electrical equipment. Commissioning of ht electrical system photo credit. 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. Assembly of such devices in a logical manner forms switchgear. The apparatus used for controlling, regulating and switching on or off the electrical circuit in the electrical power system is known as switchgear. We are all familiar with low voltage switches and rewirable fuses in our. The switch is used to manually open and close the electrical circuit in our home and electrical fuse is used to protect our household electrical circuit from over current and short circuit faults. Handbook of switchgears mcgrawhill education access.
Major inspection should be scheduled for power plant shutdowns and concentrate for low voltage. Electrical distribution needs are continuously evolving in residential, commercial and industrial sectors. The handbook of switchgears offers electrical power engineers and technicians a onestop guide to the basic design, operation, and protection of switchgears. 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. Ms28 handbook maintenance of electrical switchgear tl4, may. The term switchgear is a generic term that includes a wide range of switching devices like circuit breakers, switches, switch fuse units, offload isolators, hrc fuses, contactors, miniature circuit breakers, elcbs, gfcis etc. To discuss the need for the protection and various protection schemes. Its products and solutions cater to industries, utilities, infrastructure, building and agriculture segments.