Electrical and Electronics Engineering

a report on practical traning taken at bhilai firebrand lay down, bhilai (c. g. ) submitted to - submitted by - prof. sandeep aysha rahman c impartravanshi hod, eee submitted by - aysha rahman semester - quaternate sem branch - electric & elect ronics enginee sonorousness course- b. e. college- kruti institute of engineering science and engineering location- nardaha,raipur (c. g. ) broth up ac acquaintancement * certificate * submission ab step up sail * bhilai nerve be * sources of raw material * sub round combine of bsp * electrical rep tune ca-ca * heavy maintainence electrical * refuge * conclusion * bibilography acknoledgment I extend my bona fide thanks and gratitude to each(prenominal) population who, despite their hectic schedule managed to find time to give lectures on their concerned ara of core competence, attendened to my questionn commite patiently and dispelled my doubts through interactive correspondence. I am indebted and very grateful to extend my t hanks to Mr.Gaurav for all the knowledge they imparted to me and for making this training a joyful learning experience. My sincere thanks to Mr. P. V. V. Pawan and Mr. Lokesh for easeing me to do my training well. C E R T I F I C A T E This is to certify that the report of B. E. 4th Semester, BHILAI STEEL PLANT visualise submitted by AYSHA RAHMAN tutelage Roll No. 3412509004 & Enrollment No. AF0574 , carried out for the partial fulfillment of sine qua non for the award of Degree in unmarried man of Engineering in ELECTRICAL & ELECTRONICS of Chhattisgarh Swami Vivekananda Technical University, Bhilai (C.G. ), India. The project work as menti unmatchabled preceding(prenominal) is here by universe recommended and forwarded for examination and evaluation. ________________________________ (Signature of Head of the department) find out STEEL AUTHORITY OF INDIA LIMITED TypeOwned by State- makeed enterprise Public (NSESAIL, LSESAUD)G everyplacenment of India diligence stain Foun ded 1954 Headquarters New Delhi, India Key people Chandra Shekhar Verma (Chairman) ProductionRevenue 13. 5 billion metric tons/ category$9. 629 billion (2010) Net in deal 1. 520 billion (2010) list assets $15. 655 billion (2010) Employees 131,910 (2006) Website http//www. sail. co. in/ leaf blade warrant of India modified A Maharatna steel Authority of India limited (SAIL) is the runwaying steel-making company among the top five senior exalted schoolest avail earning corporate and one of fas taste growing Public empyrean building block in India. It is a public sector undertaking which trades publicly in the market is grownly owned by political sympathies of India and acts like an operate company.It is a fully integrated smoothing iron and steel maker, producing both elemental and special steels for domestic construction, engineering, occasion, rail representation, automotive and defence in spread outries and for sale in merchandise markets. SAIL is similarly among the five Maharatnas of the countrys Central Public Sector Enterprises and is the 16th bulkyst steel nonplusr in the world. SAIL manufactures and sells a big b clinical depression of steel products, including hot and c grey rolled sheets and c oil colours, galvanized sheets, electrical sheets, geomorphological railway products, plates, suspends and rods, stainless steel and early(a) alloy steels.SAIL produces iron and steel at five integrated plants and three special steel plants, dictated principally in the eastern and central neighbourhoods of India and situated next to domestic sources of raw materials, including the Companys iron ore, limestone and dolomite mines. The company has the distinction of being Indias mo largest producer of iron ore and of having the countrys second largest mines network. This gives SAIL a competitive edge in terms of jailed availability of iron ore, limestone, and dolomite which atomic number 18 inputs for steel making.SAILs wide ran ge of grand and planar steel products is much in demand in the domestic as well as the international market. This vital debt instrument is carried out by SAILs own Central Marketing Organization (CMO) that transacts line of work through its network of 37 Branch Sales Offices spread across the four regions,25 DepartmentalWarehouses, 42 Consignment Agentsand 27 client Contact Offices. CMOs domestic marketing effort is supplemented by its invariably widening network of unpolished dealers who meet the demands of the menialest customers in the remotest corners of the country.SAILs International affair grade (ITD), in New Delhi- an ISO 90012000 accredited unit of CMO, undertakes exports of Mild Steel products and Pig Iron from SAILs five integrated steel plants. With technical and managerial expertise and know-how in steel making gained over four decades, SAILs Consultancy Division (SAILCON) at New Delhi offers services and consultancy to clients world-wide. SAIL has a well-equi pped Research and Development Centre for Iron and Steel (RDCIS) at Ranchi which helps to produce quality steel and develop freshly technologies for the steel industry.Besides, SAIL has its own in-house Centre for Engineering and Technology (CET), Management Training Institute (MTI) and sentry go Organization at Ranchi. Our captive mines are under the control of the naked as a jaybird Materials Division in Kolkata. The surroundings Management Division and Growth Division of SAIL operate from their headquarters in Kolkata. Ownership and Management The Government of India owns about 86% of SAILs equity and retains voting control of the Company. However, SAIL, by merit of its Maharatna status, enjoys signifi push asidet operational and financial autonomy.MAJOR UNITS unified Steel whole caboodles * Bhilai Steel define (BSP) in Chhattisgarh * Dur crannyur Steel base (DSP) in West Bengal * Rourkela Steel Plant (RSP) in Orissa * Bokaro Steel Plant (BSL) in Jharkhand * IISCO Steel Plant (ISP) in West Bengal Special Steel Plants * aloneoy Steels Plants (ASP) in West Bengal * capital of Oregon Steel Plant (SSP) in Tamil Nadu * Visvesvaraya Iron and Steel Plant (VISL) in Karnataka Joint Ventures * NTPC SAIL antecedent Company Pvt. Limited (NSPCL) * Bokaro Power Supply Company Pvt.Limited (BPSCL) * Mjunction Services Limited * SAIL-Bansal Service Centre Limited * Bhilai JP Cement Limited * Bokaro JP Cement Limited * SAIL MOIL Ferro Alloys (Pvt. ) Limited * S T Mining Company Pvt. Limited * International blacken Ventures Private Limited * SAIL SCI Shipping Pvt. Limited * SAIL RITES Bengal roller coaster Industry Pvt. Limited * SAIL SCL Limited bHILAI STEEL PLANT The Bhilai Steel Plant (BSP) a public sector undertaking run by the Steel Authority of India built with Soviet co-operation and technology, and began production in 1959.Located inBhilai,Chhattisgarh isIndias only producer ofsteel quetch, and is a major producer of rails and heavy steel pl ates and structural components. In the 2004-05fiscal year, it is theSteel Authority of India Limiteds to the highest degree profitable plant. This steel plant was set up with the help of the USSR. Nine time winner of Prime Ministers Trophy for best Integrated Steel Plant in the country. The plant is the sole supplier of the countrys weeklong rail tracks of 260 metres. With an annual production readiness of 3. 53 MT of merchantable steel, the plant alike specializes in some other products such as conducting wire rods and merchant products. Since BSP is accredited with ISO 90012000 Quality Management System Standard, all sellable products of Bhilai Steel Plant come under the ISO umbrella. At Bhilai IS014001 live been awarded for Environment Management System in the Plant, Township and Dalli Mines. It is the only steel plant to get affidavit in all these areas. The Plant is accredited with SA 8000 certification for social accountability and the OHSAS-18001 certification for Occupational health and safety.These internationally trea certain(predicate) certifications add value to Bhilais products the best organizations in the steel industry. Among the long list of national awards it has won, Bhilai has bagged the CII-ITC Sustainability award for three consecutive years. Bhilai Steel Plant manages a well planned township (Bhilainagar) which as 13 sectors. It was deliberately located in what was then regarded as a remote and backward rural area, profits being secondary to employment in the planning priorities of the time.BSP presently has nearly 55,000 permanent workers on its direct pay-roll, of whom approximately three-fifths work intimate the 17 square kilometer plant and the remainder for its associated mines and quarries, and for the purpose-built BSP township. This compares with a regular workforce of 63,400 in 1987. In addition, on any one day there are at present something in the region of 8,000 contract workers sedulous by the plant and the to wnship, and a further 3,500 4,000 employed by the mines. BSP has for some years shown a profit, and is widely regarded as the most(prenominal) successful of those in the Indian public sector.It runs at its four gazillion ton capacity produces cheaper steel, and has a record of considerably more pure industrial relations than any of the other state-run steel plants, and also than the extensive majority of private sector factories which now surround it, and for which it served as a magnet. Though local job creation was one of its main objectives,and though the principle was soon established that one member from every family which had pass land should have an automatic right to BSP employment, the local Chhattisgarhis were initially reluctant recruits.Location Forty kms west of Raipur, the capital city of Chhattisgarh, along the Howrah-Mumbai railway line and the Great-Eastern highway, stands Bhilai Steel Plant (BSP). Source of Raw Materials 1. Iron Ore . Dalli, Rajahara Mines 2. Lime scar . Nandini Mines 3. Manganese . Balaghat Mines 4. mold . Sintering Plants (SP-2, SP-3) 5. Coke . Coke Ovens (Coke sorting plants) 6. Converter slag . SMS l Captive minesIron-ore Dalli-Rajhara Iron Ore Complex, 80 kms from Bhilai Limestone Nandini, 23 kms from Bhilai Dolomite Hirri, cl kms from Bhilai Coke Ovens BATT NO. NO. OF OVENS OVEN HEIGHT(M) COAL HOLDING CAPACITY PER OVEN (T) utilizable VOLUME PER OVEN CU. M. SP. HEAT CONSPN. KCAL/KG 1-8 65 4. 3 16. 8 21. 6 625-675 9&10 67 7. 0 32. 0 41. 6 625-675 honk Furnaces * 3 of 1033 Cu m capacity each * 3 of 1719 Cu m capacity each * 1 of 2355 Cu m capacity Hot Metal Capacity 4. 70 MT / year carry out FLOW OF BSP PROCUCTS OF BSP A. FINISHED PRODUCTS Rail & structural lounge Rails in 13m, 26m, 65/78 m length and welded panels of 130m / 260m length Indian Railways, merchandise Heavy Structurals Construction, Crane Rails, Cranes, Crossing sleepers, Broad gauge sleepers * Merchant Mill Lt. Structurals, Engi neering and Construction, Med. Rounds ( line of business & TMT), Heavy rounds (Plain) * Wire Rod Mill Wire Rods- Plain Construction, Wire Rods- TMT, EQ Wire Rods Electrodes * Plate Mill Plates Boilers, Defence, Railways, Ship building, LPG cylinders, merchandise B. SEMISBillets (from BBM), Re-rollers Blooms (from BBM), Narrow width slabs, CC Blooms, Killed Slabs C. Pig Iron Foundry D. By Products Coal Chemicals, Ammonium Sulphate (Fertiliser) Tar and tar products, (Pitch, Naphthalene, Creosote crude oil Road Tar, Anthracene oil, Dephenolised oil, PCM etc. ), Benzol & its products (NG Benzene, Toluene, Xylene, Solvent oil, By. Benzol etc. ), tasteful Slag Granulated slag from CHSG Plants & SGP for cement manufacture. RODUCT-MIX TONNES/ANNUM Semis 5,33,000 Rail & Heavy Structural 7,50,000 Merchant Products (Angles, Channels, Round & TMT bars) 5,00,000Wire Rods (TMT, Plain & Ribbed) 4,20,000 Plates (up to 3600 mm wide) 9,50,000 Total marketable steel 31,53,000 Requirements fo r producing of one ton of Hot Metal (Specific Consumption) Iron Ore. 459 Kg Lime Stone . 850 Kg(Depending on Sinter Usage) Manganese . 800 Kg(50% in burden) Sinter . 35 Kg Coke . 08 Kg ELECTRICAL RERAIP SHOP chew over FLOW CHART PLANT RECEIPT & ISSUE AT ERS examination MACHINE &SPARE PART ASSEMBLY COMMUTATOR WINDING & MAGNET TRANSFORMER VARNISHING TASKS through with(p) in ers * Assembles electrical separate such as alternators, generators, starting devices and switches adjacent schematic drawings, victimization hand, mould and power tools. * Repairs and rebuilds defective mechanical split in electric gets, generators and related equipment, using hand tools and power tools. * Tests for heat up, using animate gauges and thermometers. * Rewinds coils on core while core is in slots, or make replacement coils, using coil- knotty machine. deputises defective parts such as coil leads, carbon confrontationes and connecting wires using soldering equipment. * Installs, secures and aligns parts using hand tools welding equipment and electrical meters. * Rewires electrical dodgings and repairs or replaces electrical accessories. * Reassembles repaired electric gos to specify requirements and rates, using hand tools and electric meters. * Disassembles defective units using hand tools. * Measures velocity, horsepower, r. p. m, amperage circuitry and potential difference of units or parts using electrical meters and mechanical testing devices. Cuts and pull ups parts such as defective coils and insulant. * Adjusts work parts such as fan belt tension, potentiality output, tincts and springs using hand tools and verifies corrections using gauges. * Tests charges and replaces batteries. * Inspects parts for wear or damage or reads work raise or schematic drawings to determine required repairs. * Cuts and forms insularism and inserts insulation into armature, rotor coil or stator slots. * Refaces, reams and polishes commutators and machine parts to speci fied tolerances using machine tools. HEAVY MAINTENANCE ELECTRICALS MAINTENANCE OF MOTORSThe key to minimizing locomote hassles is schedule routine inspection and service. The frequency of routine service varies widely surrounded by applications. Including the aims in the maintenance schedule for the drive machine or general plant equipment is ordinarily sufficient. A ride whitethorn require additional or more patronise attention if a breakdown would driving health or safety tasks, onerous injury of production, damage to expensive equipment or other serious losses. Written records indicating eon, items inspected, service performed and move conformation are important to an effective routine maintenance program.From such records, specific problems in each application lowlife be identified and solved routinely to avoid breakdowns and production losses. The routine inspection and servicing bunghole principally be done without disconnecting or disassembling the locomot e. It involves the following factors Dirt and Corrosion 1. sweep, brush, inanity or blow accumulated dirt from the frame and air passages of the go. crappy pushs run hot when thick dirt insulates the frame and clogged passages slenderize cooling air flow. disturb reduces insulation life and eventually military campaigns labour stroke. 2. Feel for air being discharged from the cooling air ports.If the flow is weak or unsteady, internal air passages are probably clogged. lead the go from service and dissipated. 3. tab key for signs of corrosion. Serious corrosion may bode internal deterioration and/or a need for external repainting. history the removal of the motor from service for complete inspection and possible rebuilding. 4. In wet or corrosive environments, open the conduit box and cope with for deteriorating insulation or corroded terminals. Repair as needed. Lubrication Lubricate the expressions only when schedule or if they are noisy or running hot.Do NOT o ver-lubricate. extravagant stigma and oil pass pissings dirt and burn down damage thrills. Heat, fray and chill Feel the motor frame and bangs for excessive heat or trembling. find out for abnormal incumbrance. All establish a possible system failure. pronto identify and top the source of the heat, noise or vibration. Winding breakup When records indicate a tendency toward periodic winding failures in the application, score the mark off of the insulation with an insulation resistance test. much(prenominal) testing is particularly important for motors operated in et or corrosive aviations or in high ambient temperatures. Brushes and Commutators (DC rides) 1. Observe the brushes while the motor is running. The brushes moldiness ride on the commutator smoothly with little or no sparking and no brush noise ( talk). 2. Stop the motor. Be certain that * The brushes move freely in the toter and the spring tension on each brush is about adjoin. * either brush has a polished draw near over the entire working face indicating good seating. * The commutator is clean, smooth and has a polished brownish out-of-doors where the brushes ride.NOTE Always put each brush back into its original holder. Interchanging brushes decreases transposition ability. * There is no grooving of the commutator (small grooves around the circumference of the commutator). If there is grooving, remove the motor from service immediately as this is a symptomatic de nonation of a very serious problem. 3. Replace the brushes if there is any calamity they will non last until the next inspection date. 4. If accumulating, clean conflicting material from the grooves amidst the commutator bars and from the brush holders and posts. 5.Brush sparking, chatter, excessive wear or chipping, and a dirty or rough commutator indicate motor problems requiring be active service. sort 1. Typical DC Motor Brushes and Commutator Brushes and Collector Rings (Synchronous Motors) 1. fata l spots on the collector rings moldiness be distant by rubbing lightly with fine sandpaper. If not removed, these spots urinate pitting that requires re crunch the rings. figure of speech 2. Rotary Converter Armature Showing Commutator And Slip Rings. 2. An embossment of the brush, signs of arcing or uneven wear indicate the need to remove the motor from service and repair or replace the rings. . make up ones mind the collector ring brushes as described under Brushes and Commutators. They do not, however, wear as chop-chop as commutator brushes. BEARING LUBRICATION Introduction Modern motor designs usually set aside a generous supply of lubri abidet in tight military posture housings. Lubrication on a schedule basis, in conformance with the manufacturing businesss recommendations, provides optimum bearing life. Thoroughly clean the lubrication equipment and fittings before lubricating. Dirt introduced into the bearings during lubrication probably stirs more bearing failures than the lack of lubrication.Too much cover can over pack bearings and cause them to run hot, shortening their life. Excessive lubricant can find its way intimate the motor where it collects dirt and causes insulation deterioration. Many small motors are built with permanently lubricated bearings. They cannot and should not be lubricated. OILING SLEEVE BEARINGS As a general rule, fractional horsepower motors with a wick lubrication system should be oiled every 2000 moments of operation or at least(prenominal) annually. Dirty, wet or corrosive locations or heavy misdirecting may require oiling at three-month intervals or more often.Roughly 30 drops of oil for a 3- march on diameter frame to 100 drops for a 9-inch diameter frame is sufficient. consumption a 150 SUS viscosity turbine oil or SAE 10 automotive oil. Some larger motors are equipped with oil reservoirs and usually a sight gage to operate veracious level. (Fig. 3) As long as the oil is clean and light in colour, the only requirement is to fill the cavity to the proper level with the oil recommended by the manufacturer. Do not overfill the cavity. If the oil is discoloured, dirty or contains water, remove the peter out plug. Flush the bearing with fresh oil until it comes out clean.Coat the plug duds with a sealing compound, replace the plug and fill the cavity to the proper level. When motors are disassembled, wash the housing with a solvent. Discard used matt-up packing. Replace badly worn bearings. Coat the shaft and bearing surfaces with oil and reassemble. forecast 3. Cross Section of the Bearing System of a sizeable Motor GREASING BALL AND ROLLER BEARINGS Practically all Reliance fruitcake bearing motors in circulating(prenominal) production are equipped with the soap PLS/Positive Lubrication System. PLS is a patented open-bearing system that provides long, reliable bearing and motor ife regardless of mounting position. Its special internal passages uniformly distribute new dirt pu mped into the housing during regreasing through the open bearings and forces old grease out through the drain hole. The close running tolerance among shaft and inner bearing cap minimizes entry of contaminants into the housing and grease migration into the motor. The unique V-groove outer slinger seals the opening between the shaft and end bracket while the motor is running or is at rest to date sanctions relief of grease along the shaft if the drain hole is plugged. Figure 4) The frequency of routine greasing increases with motor size and severity of the application as indicated in Table 1. Actual schedules must be selected by the drug user for the specific contains. During scheduled greasing, remove both the inlet and drain plugs. substance grease into the housing using a standard grease submarine and light pressure until clean grease comes out of the drain hole. If the bearings are hot or noisy even after correction of bearing overloads (see Troubleshooting) remove the mo tor from service. Wash the housing and bearings with a good solvent. Replace bearings that show signs of damage or wear.Repack the bearings, assemble the motor and fill the grease cavity. Whenever motors are disassembled for service, check the bearing housing. Wipe out any old grease. If there are any signs of grease contamination or breakdown, clean and repack the bearing system as described in the preceding paragraph. Figure 4. Cross Section of PLS Bearing System (Positive Lubrication System) HEAT, NOISE AND VIBRATION Heat Excessive heat is both a cause of motor failure and a sign of other motor problems. The primary damage caused by excess heat is to increase the aging rate of the insulation. Heat beyond the insulations rating shortens winding life.After overheating, a motor may run satisfactorily but its efficacious life will be shorter. For maximum motor life, the cause of overheating should be identified and eliminated. As indicated in the Troubleshooting Sections, overheatin g results from a variety of different motor problems. They can be grouped as follows * WRONG MOTOR It may be too small or have the wrong starting torsion characteristics for the load. This may be the result of shortsighted initial selection or changes in the load requirements. * POOR COOLING amass dirt or abject motor location may nix the free flow of cooling air around the motor.In other cases, the motor may draw heated air from another source. Internal dirt or damage can prevent proper air flow through all sections of the motor. Dirt on the frame may prevent transfer of internal heat to the tank car ambient air. * OVERLOADED DRIVEN MACHINE Excess loads or jams in the impelled machine force the motor to supply higher(prenominal) torque, draw more current and overheat. Table 1. Motor Operating Conditions Motor Horsepower Light business(1) Standard Duty(2) Heavy Duty(3) Severe Duty(4) Up to 7-1/2 10 to 40 50 to 150 Over 150 10 years 7 years 4 years 1 year 7 years years 1-1/ 2 years 6 months 4 years 1-1/2 years 9 months 3 months 9 months 4 months 3 months 2 months * Light Duty Motors operate infrequently (1 hour/day or less) as in portable floor sanders, valves, adit openers. * Standard Duty Motors operate in normal applications (1 or 2 work shifts). Examples include air fixing units, conveyors, refrigeration apparatus, laundry machinery, carpentry and textile machines, water pumps, machine tools, garage compressors. * Heavy Duty Motors subjected to above normal operation and vibration (running 24 hours/day, 365 days/year).Such operations as in steel mill service, coal and mining machinery, motor-generator sets, fans, pumps. * Severe Duty highly harsh, dirty motor applications. Severe vibration and high ambient conditions often exist. * EXCESSIVE FRICTION Misalignment, poor bearings and other problems in the driven machine, power transmission system or motor increase the torque required to drive the loads, raising motor run temperature. * ELECTRICAL OVERLOADS An electrical failure of a winding or connection in the motor can cause other Windings or the entire motor to overheat. Noise and VibrationNoise indicates motor problems but ordinarily does not cause damage. Noise, however, is usually go with by vibration. Vibration can cause damage in several(prenominal) ways. It tends to shake windings loose and mechanically damages insulation by cracking, flaking or abrading the material. Embrittlement of lead wires from excessive movement and brush sparking at commutators or current collector rings also results from vibration. Finally, vibration can speed bearing failure by causing balls to brinnell, subdivision bearings to be pounded out of square off or the housings to loosen in the shells.Whenever noise or vibrations are found in an run motor, the source should be apace insulate and corrected. What seems to be an obvious source of the noise or vibration may be a symptom of a hidden problem. Therefore, a essential investigat ion is often required. Noise and vibrations can be caused by a misaligned motor shaft or can be transmitted to the motor from the driven machine or power transmission system. They can also be the result of either electrical or mechanical unstableness in the motor. After checking the motor shaft alignment, disconnect the motor from the driven load.If the motor then operates smoothly, look for the source of noise or vibration in the driven equipment. If the disconnected motor still vibrates, remove power from the motor. If the vibration stops, look for an electrical mental unsoundness. If it continues as the motor coasts without power, look for a mechanical unbalance. Electrical unbalance occurs when the magnetic attraction between stator and rotor is uneven around the periphery of the motor. This causes the shaft to deflect as it rotates creating a mechanical unbalance. Electrical unbalance usually indicates an electrical failure such as an open tator or rotor winding, an open bar o r ring in squirrel cage motors or shorted field coils in synchronous motors. An uneven air gap, usually from badly worn sleeve bearings, also produces electrical unbalance. The chief causes of mechanical unbalance include a distorted mounting, bent shaft, poorly balanced rotor, loose parts on the rotor or bad bearings. Noise can also come from the fan hitting the frame, shroud, or foreign objects inside the shroud. If the bearings are bad, as indicated by excessive bearing noise, determine why the bearings failed.Brush chatter is a motor noise that can be caused by vibration or other problems unrelated to vibration. WINDINGS Care of Windings and Insulation Except for expensive, high horsepower motors, routine inspections generally do not involve opening the motor to inspect the windings. Therefore, long motor life requires selection of the proper enclosure to protect the windings from excessive dirt, abrasives, moisture, oil and chemicals. When the need is indicated by severe opera ting conditions or a history of winding failures, routine testing can identify deteriorating insulation.Such motors can be removed from service and repaired before unforeseen failures stop production. Whenever a motor is opened for repair, service the windings as follows 1. Accumulated dirt prevents proper cooling and may absorb moisture and other contaminants that damage the insulation. Vacuum the dirt from the windings and internal air passages. Do not use high pressure air because this can damage windings by driving the dirt into the insulation. 2. Abrasive dust drawn through the motor can abrade coil noses, removing insulation. If such abrasion is found, the winding should be revarnished or replaced. . Moisture reduces the dielectric strength of insulation which results in shorts. If the inside of the motor is damp, dry the motor per information in Cleaning and Drying Windings. 4. Wipe any oil and grease from inside the motor. Use care with solvents that can attack the insulati on. 5. If the insulation appears brittle, overheated or cracked, the motor should be revarnished or, with severe conditions, rewound. 6. Loose coils and leads can move with changing magnetic fields or vibration, causing the insulation to wear, crack or fray. Revarnishing and retying leads may correct baby bird problems.If the loose coil situation is severe, the motor must be rewound. 7. Check the lead-to-coil connections for signs of overheating or corrosion. These connections are often exposed on large motors but taped on small motors. Repair as needed. 8. Check wound rotor windings as described for stator windings. Because rotor windings must withstand centrifugal forces, tightness is even more important. In addition, check for loose pole pieces or other loose parts that create unbalance problems. 9. The cast rotor rods and end rings of squirrel cage motors rarely need attention.However, open or broken rods create electrical unbalance that increases with the number of rods broke n. An open end ring causes severe vibration and noise. interrogation WINDINGS Routine field testing of windings can identify deteriorating insulation permitting scheduled repair or replacement of the motor before its failure disrupts operations. Such testing is good practice especially for applications with severe operating conditions or a history of winding failures and for expensive, high horsepower motors and locations where failures can cause health and safety problems or high economic loss.The easiest field test that prevents the most failures is the shew-insulation or 127 megger test. It applies DC voltage, usually 500 or gramme volts, to the motor and measures the resistance of the insulation. NEMA standards require a minimum resistance to ground at 40 degrees C ambient of 1 mega ohm per kv of rating plus 1 mega ohm. Medium size motors in good condition will generally have mega ohmmeter readings in excess of 50 mega ohms. modest readings may indicate a seriously reduced i nsulation condition caused by contamination from moisture, oil or conductive dirt or deterioration from age or excessive heat.One megger reading for a motor means little. A curve recording resistance, with the motor cold and hot, and date indicates the rate of deterioration. This curve provides the information needed to decide if the motor can be safely left in service until the next scheduled inspection time. The megger test indicates ground insulation condition. It does not, however, measure turn-to-turn insulation condition and may not pick up localized weaknesses. Moreover, operating voltage peaks may stress the insulation more severely than megger voltage.Experience and conditions may indicate the need for additional routine testing. A test used to designate existence of a safety margin above operating voltage is the AC high potential ground test. It applies a high AC voltage (typically, 65% of a voltage times twice the operating voltage plus 1000 volts) between windings and f rame. Although this test does detect poor insulation condition, the high voltage can arc to ground, burning insulation and frame, and can also actually cause failure during the test. It should never be applied to a motor with a low megger reading.DC rather than AC high potential tests are becoming popular because the test equipment is littler and the low test current is less dangerous to people and does not create damage of its own. CLEANING AND DRYING WINDINGS Motors which have been flooded or which have low megger readings because of contamination by moisture, oil or conductive dust should be thoroughly cleaned and dried. The methods depend upon available equipment. A hot water hose and detergents are commonly used to remove dirt, oil, dust or salt concentrations from rotors, stators and connection boxes.After cleaning, the windings must be dried, commonly in a forced-draft oven. Time to obtain acceptable megger readings varies from a couple hours to a some days. BRUSH AND COMMUT ATOR CARE Some maintenance people with many relatively trouble-free AC squirrel cage motors forget that brushes and commutators require more frequent routine inspection and service. The result can be unnecessary failures between scheduled maintenance. Many factors are involved in brush and commutator problems. All generally involve brush sparking usually accompanied by chatter and often excessive wear or chipping.Sparking may result from poor commutator conditions or it may cause them. The degree of sparking should be determined by careful visual inspection. The illustrations shown in Fig. 5 are a useful guide. It is very important that you gauge the degree number as accurately as possible. The solution to the problem may well depend upon the trueness of your answer since many motor, load, environmental and application conditions can cause sparking. It is also imperative that a remedy be determined as quickly as possible. Sparking generally feeds upon itself and becomes worse with time until serious damage results.Some of the causes are obvious and some are not. Some are constant and others intermittent. Therefore, eliminating brush sparking, especially when it is a chronic or recurring problem, requires a thorough review of the motor and operating conditions. Always recheck for sparking after correcting one problem to see that it solved the total problem. Also remember that, after grinding the commutator and properly reseating the brushes, sparking will occur until the polished, brown surface reforms on the commutator. Figure 5. Degrees of Generator and Motor SparkingNOTE Small sparks are yellow in colour, and the large sparks are white in colour. The white sparks, or blue-white sparks, are most detrimental to commutation (both brush and commutator). First consider external conditions that happen upon commutation. Frequent motor overloads, vibration and high humidity cause sparking. Extremely low humidity allows brushes to wear through the needed polished b rown commutator surface film. Oil, paint, acid and other chemical vapours in the atmosphere contaminate brushes and the commutator surface. Look for obvious brush and brush holder deficiencies 1.Be sure brushes are properly seated, move freely in the holders and are not too short. 2. The brush spring pressure must be equal on all brushes. 3. Be sure spring pressure is not too light or too high. Large motors with adjustable springs should be set at about 3 to 4 pounds per square inch of brush surface in contact with the commutators. 4. Remove dust that can cause a short between brush holders and frame. 5. Check lead connections to the brush holders. Loose connections cause overheating. Look for obvious commutator problems 1. Any condition other than a polished, brown surface under the brushes indicates a problem.Severe sparking causes a rough blackened surface. An oil film, paint spray, chemical contamination and other abnormal conditions can cause a blackened or discolored surface a nd sparking. Streaking or grooving under only some brushes or flat and burned spots can result from a load twin and cause motor electrical problems. Grooved commutators should be removed from service. A brassy appearance shows excessive wear on the surface resulting from low humidity or wrong brush grade. 2. High mica or high or low commutator bars make the brushes jump, causing sparking. 3.Carbon dust, papal bull foil or other conductive dust in the slots between commutator bars causes shorting and sometimes sparking between bars. If correcting any obvious deficiencies does not eliminate sparking or noise, look to the less obvious possibilities 1. If brushes were changed before the problem became apparent, check the grade of brushes. Weak brushes may chip. Soft, low abrasive brushes may allow a thick film to form. High friction or high abrasion brushes wear away the brown film, producing a brassy surface. If the problem appears only under one or more of the brushes, two different grades of brushes may have been installed.Generally, use only the brushes recommended by the motor manufacturer or a qualified brush expert. 2. The brush holder may have been reset improperly. If the boxes are more than 1/8 from the commutator, the brushes can jump or chip. Setting the brush holder off unbiassed causes sparking. Normally the brushes must be equally spaced around the commutator and must be parallel to the bars so all make contact with each bar at the same time. 3. An eccentric commutator causes sparking and may cause vibration. Normally, concentricity should be within . 001 on high speed, . 002 on medium speed and . 04 on slow speed motors. 4. Various electrical failures in the motor windings or connections manifest themselves in sparking and poor commutation. Look for shorts or opens in the armature circuit and for grounds, shorts or opens in the field winding circuits. A weak interpole circuit or large air gap also generate brush sparking. SAFETY ACCIDENT in indu strial sector defines any incident which has potential to cause injury to human, loss of property and damage to environment. Causes for occurrence of accident * shaky Act * Unsafe Conditions Hazards * Conditions prevailing in work place finally leading to accidents.Types * mechanically skillful * Electrical * Chemical * Environmental Precautions * Look overhead * Watch locomote * Wear shoes and helmets * Take care of the flow opening * repeal lose clothing * Always carry your I-D card CONCLUSION In this project, I have studied the working of electrical repair stock and about the function of Bhilai steel plant. I have obtained some knowledge about * Rolling mill * Blast furnace * Electrical repair shop * Motor windings BIBLIOGRAPHY NOTES TAKEN DURING THE TENURE OF THE VOCATIONAL TRANING INTERNET www. google. com INTRANRT SAIL, BSP INTRANET SITE