1 / 30

SVIT - VASAD

SVIT - VASAD. ACTIVE LEARNING ASSIGNMENT ELEMENTS OF ELECTRICAL ENGINEERING. Safety and protaction. Prepared by; Patel Yash (13BEEEG121) Jungi Romit (13BEEEG132) Chauhan devraj (13BEEEG126) Pandya jay (13BEEEV134) GUIDED BY; Prof. Nirali A Rathod. INTRODUCTION.

cala
Télécharger la présentation

SVIT - VASAD

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SVIT - VASAD • ACTIVE LEARNING ASSIGNMENT • ELEMENTS OF ELECTRICAL ENGINEERING

  2. Safety and protaction • Prepared by; • Patel Yash (13BEEEG121) • Jungi Romit (13BEEEG132) • Chauhan devraj (13BEEEG126) • Pandya jay (13BEEEV134) • GUIDED BY; Prof. Nirali A Rathod

  3. INTRODUCTION • From 19th century use of electricity was started. • Electricity is use in domestic & industrial purpose. • Proper precautions should be taken for the safety and protection of electricity otherwise it may even lead to death.

  4. Electric shock • An electric shock can occur upon contact of a human’s body with any source of voltage high enough to cause sufficient current through the muscles or hair . • The minimum current a human being can feel is thought to be 1 milli ampere(mA). • The death caused due to electric shock is referred to as electrocution.

  5. Effects of electric shocks • Psychological • Burns • Ventricular fibrillation • Neurological effects • Lethality of shock

  6. SAFETY RULES

  7. DOMESTIC CONSUMER • Use standard pins to tap supply of power from the plug points . • Always use standard ISI marked materials even though they may cost a little more . • Replace a fused bulb only after switch in it off. • Keep a bulb in place in all lamp holders in the house.

  8. Commercial consumer • Get all your wiring done only through a licensed contractor. • Do not allow tying up of advertisement boards, • Do not allow loading of a vehicle to a height that its run disk of coming in contact with overhead supply lines.

  9. Industrial consumer • Always treat a circuit as “alive” unless until it is proved otherwise beyond doubt. • Do warn others when they happen to be dangerously close to high tension electrical apparatus. • Do turn away your face whenever a flash or an arc is expected. • Keep rubber mats before the electrical switches. • Do not allows usage of frail wires with worn out insulation.

  10. Continued… • Do not go running belts of machine components. • Do not close or open a switch hesitatingly. always do it firmly and quickly. • Place “men at work” sign on all switches before commencing work . • Do not throw water on live equipments in case of electrical fire.

  11. What is earthing: • The term earthing or grounding means connecting the electric equipment to the general mass of the earth such that there is always an immediate discharge of energy taking place without any danger of electric shock • If the metallic part of the electric appliance comes in direct contact of earth live wire, the metal will begin to get charged

  12. Methods of reducing earth resistance: • 1) material and size of the earth electrode • 2) moisture content present in soil and the soil temperature • 3) depth to which the earth electrode is embedded in the soil • Two methods generally used for earthing: • 1) pipe earthing 2) plate earthing

  13. Pipe earthing • Here a galvanized iron pipe of approved length and diameter is used as the earth electrode. • The pipe size will be determined by ; • (A) the current to be carried • (B) the soil condition • Pipe earthing method is shown in figure. The bottom level of pipe should be surrounded by coke or charcoal for a distance of 15 cm around the pipe • This will increase the effective area of earth up to the periphery of the clock bed. • There by the earth resistance decreases

  14. Many times the coke is impregnated with salt and alternate layers of coke and salt are used • A funnel is seen connected to the main galvanized iron pipe through a 19mm diameter pipe. • This funnel facilitates pouring of about 3-4 buckets of water into the pipe in summer season.

  15. plate earthing • here the connection is made using a galvanized iron plate or a copper plate • According to standard, the dimensions of G.I. plate should not be less than 60*60 *6.35mm and that of the copper plate should not be less than 60*60*3.18mm • The plat is kept with its face vertical at a depth of about 3 m and is embedded in alternate layers of coke and salt to a distance of 15cm surrounding the plat • The funnel is provided for wetting the soil • The earth wire here is securely bolted to the earth plate with the help of nuts bolts and washers • This nuts and bolts should be of copper if copper plat is used and of galvanized iron

  16. Fuses: • Fuse Is simplest device,which brakes the circuit under abnormal condition • It is used for overload/short circuit protection in medium voltage (up to 33kV) and low voltage (up to 400V) installations.

  17. Types of fuses • Fuses are classified as : • Semi closed or rewirable type • Totally enclosed or catridge type • Dropout fuse • Explusion fuse • H.R.C fuse • Striker fuse • Switch fuse

  18. ADVANTAGES OF FUSES: • Speed of operation is very high • Maintenance cost is practically zero • They are capable of clearing high as well as low faults current • they provide reliable operation • DISADVANTAGES: • Head produced by the arc may affect the associated switches • They have to be replaced after each operation

  19. Mcb : • Miniature circuit breaker and moulded case circuit have a feature of a good h.r.c. fuse and a good switch. • These can be used for switching purpose under normal operating condition and circuit breaker under overloading. • All other metal parts are made up of nonferrous ,non-rusting type materials. • These are used in low voltage domestic, commercials and industrial application.

  20. Photos of mcb

  21. specification • miniature circuit breaker are available following… • Current ratting : 5,10,15,20,30,40 amp • Voltage rating :a.c. voltage rating – 240v/415 • d.c. voltage ratting – 50v/110 • Rupturing capacity : 3ka at 50v

  22. mccb(moulded case circuit breaker) • mccb is a operating switch which is use mannualy under normal operating condition for on & off • under fault condition it automatically trips the circuit. • When the contacts of mccb are opened under normal condition. • following are certain ratings of mccb • voltage ratting - 240v/415v (ac) • current ratting - 5,10… upto 60 amps • breaking capacity – 3 Ka

  23. Photo of mccb

  24. Earth leakage circuit breaker (elcb) • the metal housing of the induction of the induction motor is always connected to earth. • if the user standing on earth touches the “live” point, • the protection against such current is essential and it is provide by device called (elcb) • operation under the fault condition : • when the fault occurs , the leakage current start flowing through conductor as explained earlier. • So there will be non zero flux set up in current transformer core.

  25. Elcb for three phase circuit : • the same principle can be extend if the ac supply is 3 phase type. • under normal operating condition the current are balanced and output of ct negligible small. • for three phase passed through the ct core to search for any imbalance leakage fault.

  26. Photo of elcb

More Related