Facebook Twitter Instagram
    Trending
    • LIST OF B.TECH/M.TECH PROJECT IDEAS (MATLAB SIMULATION)
    • Job Opportunities for Electrical Engineers 
    • Energy Meter Apex 100
    • Testing of Circuit Breaker
    • Faults in Distribution Lines
    • Distribution System Overview
    • Transmission Towers
    • TRANSFORMER MAINTENANCE
    Learn With Electric Know How
    • Home
    • Generation
      • Hydropower Station
      • Thermal Power Station
      • DISTRIBUTED ENERGY SOURCES
      • Diesel Generator
      • Industrial Tools
      • DC System-Generating Stations
    • Transmission
      • High Voltage DC Transmission
      • High Voltage AC Transmission
      • Three Phase Control Wiring
    • Distribution
      • Distribution System Overview
      • Faults in Distribution Lines
    • Protection
      • Power System Protection
        • Types of Fault in Power System
        • Circuit Breaker
      • OVERVIEW OF TRANSFORMER PROTECTION
        • Differential Protection of Transformer
      • OVERVIEW OF GENERATOR PROTECTION
      • Distance Protection
      • Electrical Safety
    • Switchgear
      • Electrical Sub-Station
        • BATTERY SYSTEM IN GRID SUBSTATION
        • Operation of Float Cum Boost Charger
        • Protection Circuitry of Battery Charger
        • Transformer
          • INSULATION RESISTANCE OF TRANSFORMER
          • WTI AND OTI in Power Transformer
          • Transformer Oil Dielectric strength
        • Sub-Station Operation
        • Multiplying Factor for Energy Meter
      • Current Transformer
      • Potential Transformer
      • Isolator in Substation
      • Electrical Busbar
      • Insulators
      • Clamps and Connectors
      • Fire Fighting System
      • Lightening Arrester
      • Gas Insulated Substation
        • Local Control Cubicle
        • SF6 circuit breaker gas compartment
    • Q&A
      • FAQS ON CT
      • POWER SYSTEM
      • FAQ ON BUSBAR
    Learn With Electric Know How
    Home»Q&A»Lightening Arrester
    Q&A

    Lightening Arrester

    madhusmitaBy madhusmitaNovember 25, 2022Updated:March 16, 2023No Comments3 Mins Read
    Facebook Twitter Pinterest LinkedIn Tumblr Email
    Share
    Facebook Twitter LinkedIn Pinterest Email
    Lightening Arrester

    INTRODUCTION

     This electrical Lightening Arrester(LA) training course introduces basic safe operational and field diagnostics of LAs with a focus on safe operation, testing, and maintenance of the LAs’ normally installed in substations.

    What is a surge arrester in the substation?

    A surge arrester is a device to protect electrical equipment from over-voltage transients caused by external (lightning) or internal (switching) events.

    Where is the surge arrester placed in the substation?

    To protect a unit of equipment from transients occurring on an attached conductor, a surge arrester is connected to the conductor just before it enters the equipment.

    What is arrester used for?

    The purpose of using a surge arrester is to always limit the voltage across the terminals of the equipment to be protected below its insulation to withstand voltage. This is achieved by connecting elements with an extremely nonlinear voltage-current characteristic (varistor) in parallel to the terminals of the equipment.

    How Does a Lightning Arrester Work?

    • Metal oxide (MO) surge arresters containing ceramic MO elements mainly made from zinc oxide and bismuth oxide are used.
    • The resistor elements offer non-linear resistance such that for normal frequency the power system voltage the resistance is high and the lightning arrester does not conduct.
    • When a surge voltage travels along the line and comes to the arrester the gap breaks down and the resistance being low the surge is diverted to the earth.
    • After a few microseconds, the surge vanishes and the power frequency voltage is set up across the arrester and the arc current reduces.
    • All electrical equipment in an electrical system needs to be protected from voltage surges.
    • The rating of the arrester, the class of the arrester, and the location of the arrester all play a part in surge protection.
    • Surge arresters protect the equipment of transmission and distribution systems, worth several magnitudes more than the arresters themselves, from the effects of lightning and switching overvoltages.

    What are the tests conducted on surge arrester?

    1. Insulation Withstand Test- is an electrical test carried out  on a component or product to determine its insulation strength.
    2. Residual Voltage test This test confirms that no dangerous voltages are present after the supply has been removed as a result of circuits retaining a charge.
    3. Power Frequency Voltage versus Time curve
    4. Internal Partial Discharge Test
    5. Moisture ingress Test (For Station type Surge Arrester)

    Causes for Failure of Metal Oxide Surge Arresters

    • Incorrect arrester specification corresponding to actual system voltage and overvoltage stress
    • Overloading due to:

    o Temporary overvoltages (cracking, puncturing)

    o Switching overvoltages (cracking, puncturing, and flashover)

    o Lightning overvoltage (change of characteristic/aging, flashover, puncturing).

    • External pollution or moisture penetration
    • The consequence of aging: Increase in the continuous resistive leakage current. This is a good indicator of the arrester’s condition.

    Methods for Monitoring of degradation of MOSA

    • Visual inspection

                   Locating external abnormalities on the arrester gives practically no information about the internal of the arrester.

    • Surge counters

                   Frequently installed on MOSA, but has no practical use for diagnosis of the condition of the arresters.

    • Temperature measurements–Thermo Vision

                   Detects the increased block temperature on the housing surface of the arrester.

    • Leakage current measurements

                   For in-service testing, the method with the indirect determination of the resistive leakage current with compensation for harmonics in the voltage provides the best available information quality with respect to diagnostic efficiency.

    Share. Facebook Twitter Pinterest LinkedIn Tumblr Email
    Previous ArticleIsolator in Substation
    Next Article Clamps and Connectors
    madhusmita
    • Website
    • Facebook
    • Instagram
    • LinkedIn

    Related Posts

    LIST OF B.TECH/M.TECH PROJECT IDEAS (MATLAB SIMULATION)

    May 16, 2023

    Job Opportunities for Electrical Engineers 

    April 8, 2023

    FAQ ON BUSBAR

    November 25, 2022

    Comments are closed.

    Recent Posts
    • LIST OF B.TECH/M.TECH PROJECT IDEAS (MATLAB SIMULATION)
    • Job Opportunities for Electrical Engineers 
    • Energy Meter Apex 100
    • Testing of Circuit Breaker
    • Faults in Distribution Lines
    Recent Comments
    • Faults in Distribution Lines - Learn With Electric Know How on Distribution System Overview
    • POWER SYSTEM - Learn With Electric Know How on Distribution System Overview
    • POWER SYSTEM - Learn With Electric Know How on Thermal Power Station
    • Basics of Power System Protection - Learn With Electric Know How on OVERVIEW OF GENERATOR PROTECTION
    • Functions and Performance Requirements of Excitation Systems - Learn With Electric Know How on TYPES OF EXCITATION SYSTEM
    Archives
    • May 2023
    • April 2023
    • March 2023
    • December 2022
    • November 2022
    Categories
    • Distribution
    • Generation
    • Protection
    • Q&A
    • Switchgear
    • Transmission
    • Uncategorized
    Meta
    • Register
    • Log in
    • Entries feed
    • Comments feed
    • WordPress.org

    Quick Links

    • Home
    • About Us
    • Contact Us

    Post Categories

    • Generation
    • Transmission
    • Distribution
    • Protection
    • Switchgear
    • Q&A

    Vip Link

    • Privacy Policy
    • Disclaimer
    • Terms and Conditions

    Contact Us

    • [email protected]
    Youtube Linkedin