DOCSLIB.ORG

Transfer Switches

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Transfer Switches POWER SYSTEMS TOPICS 112 Understanding the Withstand and Close-On Ratings for TRANSFER SWITCHES AUTHOR INTRODUCTION MIKE LITTLE Principal Engineer Numerous short circuit current ratings and references exist for transfer Kohler Co. switches that are often confusing and seemingly contradictory. This paper Power Systems Division provides some explanation and clarification to help engineers specify the proper equipment to meet local and national regulations. For an electrical system to operate safely, the design should consider a variety of scenarios where things do not go as planned. One of those scenarios is when a short circuit occurs in the system and causes extremely high currents. An electrical system needs to be designed to safely react to these extreme conditions and, ideally, to continue to function afterwards. This article looks at automatic transfer switches (ATS) which are integral pieces of the power distribution system that help ensure power for home, office, factory or process, when served by an emergency or standby generator in addition to the local utility. This paper also aims to help engineers understand what the withstand and close-on ratings (WCR) means and provide background information to allow the proper sizing and selection of the transfer switch. Two key abilities of the transfer switch are tested under the WCR: the quantified ability to withstand fault currents for a specified period of time while maintaining functionality; and the ability to close into a fault current and continue to operate. Both abilities are critical to allow the electrical system to sustain a fault current with minimal impact. SELECTING AN ATS I. UNDERSTAND DAMAGES CAUSED BY HIGH II. STUDY THE POWER SYSTEM FAULT CURRENTS Detailed knowledge is required about the Prior to selecting an ATS, it is important to section of the power system where the ATS understand how high fault currents can will be connected. Modern power system damage an electrical system’s functionality. studies are performed by engineers who build High fault currents flowing through power models of power systems using computer system components can create significant software. The study covers all system heat over the duration of the fault, which parameters including the sizes, conductors’ can cause damage to the insulation on quantities and lengths, transformer ratings conductors and transformers, as well as and impedances, overcurrent protective to the overcurrent protective devices and devices and related Time-Current Curves switch contacts. (TCC), and other relevant data. Fault currents can also create significant Through a power system study, engineers mechanical stress, as they produce high compute fault currents at each system bus for magnetic forces that can bend bus structures, normal, contingency and future system separate switch contacts, or cause power configurations and evaluate capability of cables to pull out and energize surrounding upstream and downstream protective devices. structures or circuits. All these factors should Additionally, engineers provide computations be taken into consideration during the on subjects such as available arc-fault electrical system’s design phase in energies at each bus along with analysis and conjunction with the power system study recommendations on device coordination. and proper selective coordination. Based on the study results, the specifier can then make an intelligent ATS selection. Figure 1 III. APPLY SELECTIVE COORDINATION AND FAULT ISOLATION As part of the power system study, it is important to understand the concept of selective coordination with overcurrent protective devices. Proper selective coordination ensures that an electrical fault will be cleared as close to the point of occurrence as is practical. The National Electrical Code (NEC), in the Fault Fault 2017 standard, defines selective coordination as the following in Article 100: “Localization of an overcurrent condition to restrict outages to the circuit or equipment Without Selective Coordination With Selective Coordination affected, accomplished by the selection and installation of overcurrent protective devices Tripped Tripped and their ratings or settings for the full range Affected Outage Affected Outage of available overcurrents, from overload to the maximum available fault current, and for the full range of overcurrent protective device opening times associated with those overcurrents.” 2 / Withstand and Close on Ratings POWER SYSTEMS TOPICS 112 Figure 1 on the left shows an electrical 10 kA available fault current, therefore system without selective coordination. requiring a much smaller WCR which allows Without selective coordination, when a fault more flexibility regarding selection of occurs at a particular load, several levels of overcurrent devices and ATS model. overcurrent protective devices (even the main disconnect) may see the fault and react, or V. CONCLUSION trip. When this happens, it may potentially impact the entire facility. Engineers should conduct a comprehensive power system study prior to installing an ATS. Figure 1 on the right illustrates proper The study would help determine available fault selective coordination, which is equipped with currents from sources present or considered properly timed overcurrent protective devices. for future installation and recommend When a fault current happens, the upstream appropriate WCRs for the ATS in Figure 1. breakers from the fault "withstand" the current Only with an accurate understanding of the long enough that only the nearest overcurrent electrical system and its design implications, protective device will open and clear the fault. can a proper ATS be selected to provide In this way, most of the distribution circuit safe, robust and cost-effective solutions. This remains unaffected and operational. prestudy will also help avoid problems that can occur during the commissioning phase, IV. IDENTIFY THE REQUIRED WCR such as impermissible disconnect and ATS FOR THE ATS combinations, incorrect switch purchase or failure to satisfy a specification. Engineers need to identify the required WCR for the point of installation. To ensure safety, the ideal WCR should be high enough that the UNDERSTANDING THE FOUR transfer switch can handle available fault WCR TYPES currents. At the same time, the WCR should not be overrated, which may result in a higher WCR are fundamentally the short-circuit cost and larger switch, contributing to a lack ratings of a transfer switch. Various standards, of space in the electrical room. such as UL 1008, define the methods and criteria for testing and reporting the WCR For example, two identical 200 A-rated ATS levels. The four main types of WCR installed at different parts of a facility may (Figure 2) are specific breaker ratings, time- require different WCR levels. If a specifier based ratings, short-time ratings and fuses. installs a 200 A-rated ATS close to the utility The categorization is based on how the service entrance, it may need to withstand a overcurrent protection of the transfer switch 35-kA available fault current as determined by is accomplished and tested. the power system study. To achieve the required WCR, the ATS may be upsized or The WCR for any KOHLER® ATS is found in may require specific upstream overcurrent the model’s specification sheet and near the protection. Meanwhile, the same 200 A ATS contactor inside the enclosure. installed in a branch circuit on the other side of the facility may only need to withstand a Withstand and Close on Ratings / 3 Typical contactor rating nameplate: SUITABLE FOR CONTROL OF MOTORS, ELECTRIC DISCHARGE AND TUNGSTEN LAMPS, ELECTRIC HEATING EQUIP. WHERE THE SUM OF MOTOR FULL LOAD AMPS FigureAND A 2MPS OF OTHER LOADS DOES NOT EXCEED THE SWITCH AMP RATING AND THE TUNGSTEN LOAD DOES NOT EXCEED 30 PERCENT OF THE SWITCH RATING. Typical contactor rating nameplate: TSyUpITicaABlL cEon FOtacR CtorON rTaRtingOSL HnOOaFmR MTeO-pCTlIaORCUtRe:S,I TE LWEICTHTRSTICANDDIS/CHCLOARSIGNEG AND TUNGSTEN SLAUMITPSAB,L EEL FEOCRTR CICONHTERAOTILAN ONDGF E MSQHOUOTIPOR. TRW-STH,I MERELE CURRC TTHREIC ESNDUTIMS RCHOAFTA MIRNOGTESO ARN FDU TLUNL LGOSATDEANM PS LAANDMPS AM, PSELE OCFT ORITCHHEERA LTOINAGD SE QDUOIESP. WNOHTEREEX CTEEHED S TUHME O SFW MITOCHTO ARM FPU LRLALTOINAGD AANDMPS TH E WATUNNDHEG NAS MPTPSREON TO LEFOC AOTDTE HDE OBYRE SL AO N ACODIRTS CE DUXOICTESEE BR DNEAKE O3T0 PEERXRC,C TEEHEIDNS TT RHOAEFN TSSHWFEEIT RSCH WSWI TAICMTHCHP RR AIASTT ISINNUGGI.T AABNDLE T HE FTOUNRG USSETE INN LAOCAIDRCU DOIETS C NAPABOT ELXEC OEEF DD E30L IVEPERRCINEGN TH OEF STHHOER STW-CITIRCUCH RITACURRTING. ENT FOR THypEi caMAl XcIonMUtMac TtorIM EraDURtingA nTaIOmNe pAlNDate V: OLTAGE MARKED BELOW. SUITABLE FOR CONTROSL HOOFR MTO-CTIORCURS,I TE LWEICTHTRSTICANDDIS/CHCLOARSIGNEG AND TUNGSTEN LAMPS, ELECTRIC HEATSIANHNDGO ER SQTH-UCOIPIRRCU. TW-THITME REW ECURRIT THHSET EASNNDUTM / RCOALFTO MISNOIGNTSGO R FULL LOAD AMPS THE CIRCUIT BREAKER MUST INCLUDE AN INSTANTANEOUS TRIP RESPONSE UNLESS AND AMPS OF OTHER LOAANDDS SDHOOESRT N-TOIMTEE XCURRCEEDE NTHT ER SAWTINITGCHS AMP RATING AND THE THE AVAILABLE SHORT-CIRCUIT CURRENT IS LESS THAN OR EQUAL TO THE SHORT- WTUNHEGNS PTREONT LEOCATDE D OBYES A N COIRT CEUXICTEE BRDEAKE 30 PERRC, THEINST ROAFNTSHFEE RS WSWITICTHCH R AIST ISNUGI.TABLE WFTOIMHRE N UR SEPART IONTG AE OCCTFIRCU ETDH EBYITT CRAAPABA CNIRSFCLEUERIT OS BFWR DIEAKETECHLIVE ARNDR, TINH TGIHS TEHR CEAI RCUNSSHFOEIRTR TB -SRCWEAKEIRCUITCHIRT ISCURRINC SULIUDTEABNESTL E FA O R SHORT-TIME TRIP RESPONSE. FTOHER MUASEX IIMNU
Load more

Recommended publications
  • Electrical Repairman
    VIRGINIA DEPARTMENT OF MINES, MINERALS & ENERGY DIVISION OF MINES ELECTRICAL REPAIRMAN MAINTENANCE FOREMAN & CHIEF ELECTRICIAN CERTIFICATION STUDY GUIDE 2011 Copyright 1997 Commonwealth of Virginia Commonwealth of Virginia Department of Mines, Minerals, and Energy Division of Mines P.O. Drawer 900 Big Stone Gap, VA 24219 (276) 523-8100 Repairman, Maintenance Foreman, and Chief Electrician Certification Study Guide INTRODUCTION The purpose of the Electrical Repairman, Maintenance Foreman and Chief Electrician Certification Study Guide is to assist a qualified applicant in obtaining the Underground Electrical Repairman, Maintenance Foreman and/or Chief Electrician certification(s). The Board of Coal Mining Examiners (BCME) may require certification of persons who work in coal mines and persons whose duties and responsibilities in relation to coal mining require competency, skill or knowledge in order to perform consistently with the health and safety of persons and property. The purpose of the electrical repairman’s section is to assist an applicant who possesses one-year electrical experience in underground coal mining in obtaining an Underground Electrical Repairman certification in accordance with the regulations for the BCME’s certification requirements. Applicants may be given six months credit for electrical educational training from a college, technical school, or vocational school. In addition, each applicant shall pass examinations in first aid and gas detection. The purpose of the maintenance foreman’s section is to assist the electrical repairman who possesses three years of electrical experience in underground coal mining in obtaining a Maintenance Foreman certification. Knowledge of the material in the repairman’s and maintenance foreman’s sections is needed to prepare for the examination.
    [Show full text]
  • Understanding the Grounding Continuity Test the “Understanding the Product Safety Tests” Series
    Weekly Whitepaper Week #533 -23-18 Understanding the Grounding Continuity Test The “Understanding the Product Safety Tests” Series The Grounding Continuity Test (aka Earthing Continuity Test) is one of the most common product safety tests. It is performed on products that have a ground (earth) connection by Certification labs as part of the product Certification and by electrical product manufacturers on 100% of production. Let’s review the elements of this test. Key Definitions: a) Grounding vs. Earthing: Grounding & Earthing are interchangeable terms with identical meaning. In the US & Canada, the term “grounding” is used, while most other countries use the term “earthing”. Accordingly, UL & CSA standards use the term “grounding” while IEC & EN standards use the term “earthing”. This whitepaper uses the term “grounding” which can be replaced throughout with the term “earthing”. b) Protective Current Rating: Some standards specify using a test current level that is based on the “protective current rating”. The protective current rating is the current rating for the device that provides “branch-circuit overcurrent protection”. It is the rating of a circuit breaker or cartridge fuse = this device can be part of the product, but it is usually part of the building electrical system (i.e. the circuit breaker in the breaker panel). • Branch circuit rated circuit breakers and fuses can handle high short-circuit current and are therefore much larger than “supplementary” protectors = the types of circuit breakers and fuses included in many products do not provide branch circuit protection and therefore are not considered when identifying the protective current rating. c) Protective Earth Terminal (P.E.): The P.E.
    [Show full text]
  • 7 CONTROL and PROTECTION of HYDRO ELECTRIC STATION 7.1 Introduction 7.1.1 Control System the Main Control And
    CHAPTER –7 CONTROL AND PROTECTION OF HYDRO ELECTRIC STATION 7.1 Introduction 7.1.1 Control System The main control and automation system in a hydroelectric power plant are associated with start and stop sequence for the unit and optimum running control of power (real and reactive), voltage and frequency. Data acquisition and retrieval is used to cover such operations as relaying plant operating status, instantaneous system efficiency, or monthly plant factor, to the operators and managers. Type of control equipment and levels of control to be applied to a hydro plant are affected by such factors as number, size and type of turbine and generator. The control equipment for a hydro power plant include control circuits/logic, control devices, indication, instrumentation, protection and annunciation at the main control board and at the unit control board for generation, conversion and transmission operation including grid interconnected operation of hydro stations including small hydro stations. These features are necessary to provide operators with the facilities required for the control and supervision of the station’s major and auxiliary equipment. In the design of these features consideration must be given to the size and importance of the station with respect to other stations in the power system, location of the main control room with respect to the equipments to be controlled and all other station features which influence the control system. The control system of a power station plays an important role in the station’s rendering reliable service; this function should be kept in mind in the design of all control features.
    [Show full text]
  • Electric Motor-Driven Mine Equipment and Accessories and High-Voltage Longwall Equipment Standards for Underground Coal Mines; Final Rule
    Monday, March 11, 2002 Part II Department of Labor Mine Safety and Health Administration 30 CFR Parts 18 and 75 Electric Motor-Driven Mine Equipment and Accessories and High-Voltage Longwall Equipment Standards for Underground Coal Mines; Final Rule VerDate 11<MAY>2000 12:47 Mar 08, 2002 Jkt 197001 PO 00000 Frm 00001 Fmt 4717 Sfmt 4717 E:\FR\FM\11MRR2.SGM pfrm01 PsN: 11MRR2 10972 Federal Register / Vol. 67, No. 47 / Monday, March 11, 2002 / Rules and Regulations DEPARTMENT OF LABOR underground coal mines and allowed the industry’s need for higher voltages the use of high-voltage longwall and the marked improvement in the Mine Safety and Health Administration equipment. However, it did not design and manufacturing technology of specifically focus on the safety issues high-voltage components, MSHA 30 CFR Parts 18 and 75 related to the use of high-voltage developed rules that establish RIN 1219–AA75 longwall equipment. The Agency requirements for safe high-voltage published a new proposed rule (57 FR electric equipment use. This rule Electric Motor-Driven Mine Equipment 39036) on August 27, 1992, related provides improved design requirements and Accessories and High-Voltage specifically to the safe use of high- for longwall equipment, consistent with Longwall Equipment Standards for voltage longwall equipment in existing requirements in 30 CFR part 18, Underground Coal Mines underground coal mines. These rules and contains provisions that also specifically addressed approval accommodate new design technology, AGENCY: Mine Safety and Health requirements for high-voltage electrical are practical, and lessen burdens on the Administration (MSHA), Labor.
    [Show full text]
  • “Electrical Safety in the Workplace”
    “Electrical Safety in the Workplace” This material was produced under Grant #SH-16609-07-60-F-26 from the Occupational Safety and Health Administration, U.S. Department of Labor. It does not necessarily reflect the views or policies of the U.S. Department of Labor, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. September 2008 “Electrical Safety in the Workplace” Course Goal – The aim of this program is to provide comprehensive on-site training to high-risk workers (i.e. skilled trades and maintenance workers) and management on the requirements of Sub Part S, and the prevention of serious injuries from electrical hazards at their worksites. Participants will develop understanding of the requirements of OSHA Sub Part “S” and NFPA, 70E and will be able to identify and reduce or eliminate electrical safety hazards in their workplace. Electrical Safe Work Practices including electrical safety principles, guidelines for qualification of personnel, job planning requirements and Management and Personal Responsibility will be covered. Section Content Objective 1 Introduction to Participants will be able to: Electrical Safety • Explain the issues (statistics) associated with poor electrical safety in the workplace. • Recall key electrical terms which are essential to understanding and meeting the requirements of key electrical safety standards; i.e. OSHA 29 CFR 1910.331-.335, NFPA 70E, NEC (NFPA 70) • Define and differentiate between qualified and unqualified persons under OSHA Sub Part S. and the training requirements for each. • Describe the intent of an Electrical Safety Program and list the essential elements of an effective program.
    [Show full text]
  • Journal Paper Format
    International Journal of Hybrid Information Technology Vol.7, No.3 (2014), pp.105-120 http://dx.doi.org/10.14257/ijhit.2014.7.3.12 A Paper of Determination of Controlling Characteristics of the Monopolar HVDC System Rajib Baran Roy1 and Md. Ruhul Amin2 Assistant Professor1, Lecturer2 Department of Electrical and Electronic Engineering University of Information Technology and Sciences (UITS) Dhaka-1212, Bangladesh [email protected]; [email protected] Abstract Due to cost effectiveness and less electrical fault hazards, the HVDC transmission is more suitable for long distance power transmission than that for the conventional AC transmission system. Moreover the utilization of power electronics has made HVDC technology competitive and reliable in comparison to HVAC system. The controlling mechanism of the DC link (either monopolar or bipolar) is the major concern for HVDC technology. Determination of control loop for system operationOnly. needs to ILLEGAL. commensurate with the conduction period of the semiconductor switching device. Generally IGBT and MOSFET are widely used as switching device whose delay angle, advance angleis and extinction angle need to be matched with the controlling mechanism of the converter and inverter section. In this paper, the controlling characteristics of a monopolar HVDC system are determined by using MATLAB/Simulink. The Simpower tool box is used forfile designing the controlling blocks of the HVDC system. The controlling characteristics of the monopolar HVDC system can be determined from the simulation Versionresults of the gate currents of IGBT, output voltages of converter and inverter and modulation index. this Keywords: HVDC, monopolar, IGBT, delay angle, advance angle and extinction angle.
    [Show full text]
  • Ground-Fault Circuit Interrupters December 2009 Protect You from Electrical Shock Hazards Purpose of the GFCI
    Office of Compliance fast facts advancing safety, health, and workplace rights in the legislative branch Ground-Fault Circuit Interrupters December 2009 Protect You From Electrical Shock Hazards Purpose of the GFCI A ground-fault circuit interrupter (GFCI) is used to protect people from electrical shock hazards caused by malfunctioning electrical appliances. If a person is using a defective electrical appliance and also touching a wet surface or very conductive surface, the person could become part of the grounding pathway for the fault current. This condition can send a dangerous electrical current through the body, causing serious electrical shock or death. An electrical current as small as 10 milliamperes (mA) across the chest of a person is reported to cause the heart to beat irregularly, possibly resulting in death. According to the National Fire Protection Association’s (NFPA) National Electrical Code (NEC), a GFCI is “a device intended for the protection of personnel that functions to de-energize a circuit or portion thereof within an established period of time when a current to ground exceeds the values established for a Class A device.” It is installed in electrical outlets or in extension cord circuits which will quickly stop current flow in the Figure 1 Outlet with GFCI circuit when the fault current exceeds a range of about 4 mA to 6 mA, as seen in Figure 1. In protection recent years, the Occupational Safety and Health Administration (OSHA) and the National Electrical Code have expanded the applications requiring GFCIs. Where are GFCIs Required to be Used? OSHA and the NEC now require all bathroom and rooftop outlets to have GFCI protection.
    [Show full text]
  • Removal Restoration of Power
    ELECTRICAL ENGINEERING SAFETY | INFORMATION SHEET NO.4 Removal & restoration of power December 2013 Information Sheets are developed by the inspectors of electrical engineering in response to issues identified during site electrical engineering audits at extractive mines and questions raised by the mine operators. They are provided as guidance material for mine operators in the development of electrical safety standards. Purpose This information sheet is intended to assist operators at small extractive mine operations to develop procedures for the safe removal and restoration of electric power. Incorrect or unauthorised operation of electrical switching apparatus, including the resetting of electrical protection devices following a protection trip, can expose persons to unacceptable levels of risk. The outcomes sought to be achieved by this information sheet are to protect people and property from the risks associated with the removal and restoration of power at extractive operations including: · uncontrolled removal and restoration of power. · electrocution. · electric shock. · electrical burn injuries. · arc blast injuries. · injuries sustained through operation of the switching apparatus. · unintended operation of plant. · fire Scope This information sheet extends to small extractive operations in NSW. The information is intended to assist mines to develop procedures for the removal and restoration of power at all locations at the operations including: · surface areas · site buildings and structures · process plants Removal and restoration of power procedures should apply to all sources of electric power. Arrangements for the removal and restoration of power at extractive operations must form part of the site’s Mine Safety Management Plan. This information sheet does not cover practices for isolation to allow work to be carried out on electrical power circuits.
    [Show full text]
  • Using D.C. Power Fault Protectors
    STO-P Technical Paper Using d.c. Power Fault Protectors Safe DC Power for Mobile, Marine and Industrial Applications STO-P DC Power Fault Protection June 2000 Using dc Power Fault Protectors Using the latest high tech electronic equipment in a mobile or marine environment is full of electrical hazards. This paper describes how nine classes of electrical system faults threaten equipment and how "dc Power Fault Protectors" are used to prevent damage and maintain the highest operating reliability. If you design, install, or use electronic equipment in the 12, 24, or 28 Volt mobile environment, you will need to understand the hazards and consider the impact on equipment performance. Arretec UK has been a pioneer in the design and development of dc Power Fault Protection devices for over ten years. Their line of STO-P protectors are used worldwide in military, industrial, mobile and marine applications. www.sto-p.com/pfp/ Page 2 STO-P DC Power Fault Protection Contents Section 1: Overview ............................................................................ 5 Introduction Symptoms Preventable Faults Unreliable Operation Damage to Electronics Standard Solutions Lead to Further Problems STO-P’s Time Domain Approach UPS - Reserve Power The Bottom Line Section 2: Common Electrical System Faults .................................... 9 Spikes Transients Overvoltage Undervoltage Surge Electro-Magnetic Interference (EMI) Induced Electro-Motive Force (IEMF) Reverse Polarity Ripple Section 3: Applications ....................................................................... 20 Land Transport Isolation Constant Dangers Undervoltage Other Problems Marine Sources of Electrical Faults Lightning Radio/RF Interference Battery Charger Problems What STO-P Does Industrial Engine Control Systems Remote Sensing & Solar Powered Installations Customized Power Fault Protectors www.sto-p.com/pfp/ Page 3 STO-P DC Power Fault Protection Contents Section 4: Power Fault Protectors .....................................................
    [Show full text]
  • Arc Fault Detection Device Eaton.Com
    Eaton – AFDD+ - Arc Fault Detection Device Eaton.com Electrically Ignited Fires in Low-voltage Electrical Installations Guidance to the world of standards IEC 60364 Low-voltage electrical installations IEC 60364-4-42 Protection for safety - Protection against thermal effects Hidden fi re hazards ... Help! Fire! Electrically ignited fi re Fire next to the tallest building in the world On New Year’s Eve 2016, a fi re broke out in a hotel (Address Downtown Dubai) and residential building in the vicinity of the famous Burj Khalifa, currently the world’s tallest building. According to police offi cials, the direct cause of the fi re in the 63-storey building was an electric short-circuit, which occurred in between the 14th and 15th fl oor at approximately 9:30 pm local time. Flames shot up towards the sky from one side of the building and pieces of blazing debris later rained down, yet fortunately only minor injuries were reported during the evacuation process, even though people had gathered in the area for the New Year’s fi reworks display at the Burj Khalifa only a few hundred metres away. The evacuation proceeded quickly and smoothly, so the authorities decided to go through with the fi reworks display, as planned. (Source: Reuters, 20 January 2016) Did you know: 95 per cent of fi re victims die as a result of smoke inhalation? ! (Source: GDV) Major fi re in apartment building Centuries-old apartment building destroyed by electrical fi re A massive fi re tore through a nearly 200-year-old residential building in Bourne, Massachusetts (USA) on 29 May 2019.
    [Show full text]
  • Chapter-1: Control and Protection General Considerations, Technology Development
    SECTION – I CONTROL AND PROTECTIONS CHAPTER –1 CONTROL AND PROTECTION GENERAL CONSIDERATIONS, TECHNOLOGY DEVELOPMENT (Reviewed by Dr. R. Thapar) 1.1 Control System The main control and automation system in a hydroelectric power plant are associated with start and stop sequence for the unit and optimum running control of power (real and reactive), voltage and frequency. Data acquisition and retrieval is used to cover such operations as relaying plant operating status, instantaneous system efficiency, or monthly plant factor, to the operators and managers. Type of control equipment and levels of control to be applied to a hydro plant are affected by such factors as number, size and type of turbine and generator. The control and monitoring equipment for a hydro power plant include control circuits/logic, control devices, indication, instrumentation, protection and annunciation at the main control board and at the unit control board for generation, conversion and transmission operation, grid interconnected operation of hydro stations including small hydro stations. These features are necessary to provide operators with the facilities required for the control and supervision of the station’s major and auxiliary equipment. In the design of these features consideration must be given to the size and importance of the station with respect to other stations in the power system, location of the main control room with respect to the equipments to be controlled and all other station features which influence the control system. The control system of a power station plays an important role in the station’s rendering reliable service; this function should be kept in mind in the design of all control features.
    [Show full text]
  • Personal Protective Grounding for Electric Power Facilities and Power Lines
    Facilities Instructions, Standards, and Techniques Volume 5-1 Personal Protective Grounding for Electric Power Facilities and Power Lines U.S. Department of the Interior Bureau of Reclamation Denver, Colorado July 2005 REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1.T REPORT DATE (DD-MM-YYYY)T 2.T REPORT TYPET 3.T DATES COVERED (From - To)T July 2005 Final 4.T TITLE AND SUBTITLE 5a. CONTRACT NUMBER FIST 5-1 Personal Protective Grounding for Electric Power Facilities and Power Lines 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Phil Atwater, Electrical Engineer, P.E. Bureau of Reclamation 5e. TASK NUMBER Infrastructure Services Division Hydroelectric Research and Technical Services Group 5f. WORK UNIT NUMBER Denver, Colorado 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8.
    [Show full text]