DIGITAL MUTIMETER

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PRESENTATION OF IN-PLANT TRAINING ON DISTRIBUTION TRANSFORMER.

● Products Manufactured ● DISTRIBUTION TRANSFORMER ● Range : 63 KVA to 2.5 MVA ● Class : 11, 22 & 33 KV The Distribution Transformers are manufactured as per the Design confirms to IS 1180 (Part I, 2014), IEC 60076 and other relevant standards..

● RANGE OF STEP DOWN DISTRIBUTION TRANSFORMERS MANUFACTURED :-.

. Use : LV Winding machine are used in building variety of Coil and wire winding applications. These machines are manually operated machine. LV winding machine is very flexible and offers dependable and enduring performance. In the industry, it was mainly used for making LV Coils of the Transformer..

Use : Basically the laminated sheet metal cutting machine is operated by foot in the industry. The laminated sheet metal cutting machine, helps to cut the sheet metal precisely and accurately. In the industry, the lamination sheet cutting machine was mainly used for cutting CRGO steel and making laminations out of it which were used in the Core of the Transformer..

5. Oil Filtration Machine :-. 6. Transformer Test Bench :-.

7 . Regulator Type Welding Machine :-. 8. Universal Radial & Pillar Type Drill Machine :-.

● RAW MATERIALS USED IN MANUFACTURING PROCESS OF DISTRIBUTION TRANSFORMER..

● MS Sheet ( Mild Steel ) :- Transformer Tanks are made of high quality MS Sheets and Plates. ● MS Channel ( Mild Steel ) :- MS Channels are fixed at the bottom of the Core of Transformer. It is used so that the Laminations of the Core do not move from one place to another. ● MS Pipe ( Mild Steel ) :- MS Pipes are extensively used in Fabrication work in the industry. They are mainly used in connecting the Conservator and Explosion Vent to the Transformer. ● Breather Pipe :- Breather Pipe is used to install Silica-Gel Breather to the Transformer at the time of Transformer Installation at the site. ● Oil Level Gauge :- An Oil level Gauge (MOG) is a device used to indicate the position of transformer insulating oil level in Conservator of a transformer. ● Bushing Clamp :- Bushing Clamps are used for Recognition of Phase Sequence of Transformer ( R-Y-B) of HV Bushing. They also fix the HV Bushing tightly to the Transformer . ● Air Release Plug :- Air Release Plug allows air to escape from the Tank of the Transformer..

● Locking Bush :- Locking Bush is installed inside the Tank of the Transformer to the Core Coil Assembly so that the Core Coil Assembly should not move from its original place. ● Filter Valve :- Filter Valve is used for filtering Transformer Oil in the Tank of the Transformer. ● Drain Valve :- Drain valve is used to flow (Drain) the Transformer Oil from the Tank of the Transformer. ● HV Bushing :- HV bushing is a hollow electrical insulator that allows an electrical conductor to pass safely through a conducting barrier such as the case of a transformer or circuit breaker without making electrical contact with it. ● LV Bushing :- LV Bushings are used in transformers as a means of electrical connection from the outside of the tank (cables or overhead lines) to the inside of the tank (transformer windings). ● Tap Changer :- The purpose of a Tap Changer is to regulate the output voltage of a transformer by altering the number of turns in one winding and thereby changing the turns ratio of the transformer. ● Copper Patti for Earthing :- Copper is the preferred metal for grounding conductors and electrodes. This is not only due to its high degree of connectivity, but also its corrosion resistance. In most soils, copper electrodes outlast alternates such as galvanized steel..

● Silica-Gel Breather :- Silica-Gel Breather helps to prevent Atmospheric Moisture and reduces Maintenance Costs. During the breathing cycle of a transformer, it is crucial to prevent atmospheric moisture from entering the transformer, which can contaminate the oil. ● Radiators :- Radiators are equipped in a transformer with the function of cooling of the transformer oil through Natural Air or Forced Air flowing in Radiator Fins. ● Transformer Oil :- Transformer oil's primary functions is to insulate and cool a transformer. It must therefore have high dielectric strength, thermal conductivity, and chemical stability, and must keep these properties when held at high temperatures for extended periods. ● Label Plates :- Label Plates are used for indication of particular part of Transformer and they also indicate the Rating of Transformer. ● Varnish :- Varnish is applied inside the Transformer to provide a layer of Electrical Isolation and to prevent it from shorting. ● Rubber Washer :- Rubber Washer is used to prevent Leakage of Oil in the Transformer..

● Rubberised Cork Sheet :- Rubberised Cork Sheet is mainly used for sealing, isolating and insulating purpose in Transformer. ● Brazing Rod :- Brazing Rod is used for connecting/joining the ends of Copper Wire, Copper Flat. These rods are used in Gas Welding. ● Thinner :- Thinner is used in making thick paint thin and also for Cleaning of Tanks from inside. ● Red Oxide :- Red Oxide Metal Primer acts as a protective cooling that prevents rust formation on ferrous metal surfaces exposed to humidity and air. ● Cotton Tape :- Cotton Tape is used for binding materials in transformer for its good mechanical strength and insulating quality. ● Final Paint :- Painting the transformer ensures long-term protection of the high voltage assets to the Transformer..

● FLOW CHART OF MANUFACTURING PROCESS OF STEP DOWN DISTRIBUTION TRANSFORMER.

1. Winding :- ( HV Winding & LV Winding ). . . All HV & LV Windings are designed to withstand short circuit and to minimize copper usage. Windings are made using either copper or aluminium , and can be offered for oil filled transformers, VPI dry type transformers or cast resin transformers. Dry type windings are made on fibre glass mandrels to ensure there is no inadvertent tearing of the insulations..

2. Core Assembly :-. abstract. Assembly of several cores or core parts to obtain a complete core package ready for casting is known as Core Assembly. Core adhesive or core screws are used to connect the core parts. The actual assembly is performed using the suitable core assembly jigs. Core used is grain oriented steel and manufactured and designed considering the Step Lap method, including mitered joints. Using optimal design and manufacturing, air gaps are reduced between yokes and legs for reducing noise & losses. Core is bound to reduce noise & losses. Core is sourced from quality vendors to achieve best quality as well as ensure long life. Each core is inspected and losses measured prior to next process..

3. Core Coil Assembly :-. . Low voltage windings are placed near the core and high voltage windings are assembled and are placed with respect to low voltage windings. Spacers are added for adding strength. Coils are assembled using high-end insulating materials and are adequately clamped. Windings are taken after consolidation and placed on individual limbs of cores. Proper insulation scheme, spacers and routing of cables are ensured. Reblading , Brazing of Busbars and final fitting is completed. Core coil assembly is dried for over 12 hours at upto 105 degrees, until completely dry..

4. Final Assembly :-. abstract. Fully dried and consolidated core coils are taken and inserted into tanks. After tightening, fixing and cover closure, fittings and accessories are mounted. Tanks are pressure tested for 4 hours in Hot Oil Condition. Transformers are painted and paint thickness is checked and maintained. Custom painting system according to customers requirements are offers in Epoxy, Hot Zinc Spray, Powder Coating and Polyurethane..

5. Testing :-. TESTING. All transformers are tested in the Lab to National and International Standards ( IS : 2026, IEC 76, etc. ) and IS 1180 (Part I 2014)..

● Tests performed on Distribution Transformer. 1. Oil Breakdown Voltage Test :- (Oil BDV Test).

2. High Voltage Test :-. abstract. High voltage testing is carried out to guarantee sufficient proper insulation in a Distribution Transformer. It decreases the likelihood of electrical shocks and accidents. High voltage testing ensures that the safety is as per design and standards, so it tells whether the system can withstand the voltage rating that is supplied. High Voltage Test is done by giving over voltage to the transformer than its rated voltage.

3. Winding Resistance Test :-. abstract. Transformer Winding Resistance measurement is carried out to calculate the Iron losses. It is carried out as a type test as well as routine test. It is also done at site to ensure healthiness of a transformer that is to check loose connections, broken strands of conductor, high contact resistance in tap changers, high voltage leads and bushings etc..

abstract. 4. Earth Resistance Test :- ( Megger Test ).

5. Automatic Turns Ratio Test :-. aaaa tjaaa :aaa.

6. Open Circuit Test :-. LV HV Open Circuit Test on Transformer.

7. Short Circuit Test :-. Circun Test Transformer.

8. Double Voltage Double Frequency Test :- (DVDF Test).

● Quality Assurance procedures done on finished products..

6. Bushing Colour Code :- Color Code of LV & HV Bushing i.e R-Y-B & R-Y-B-N Phase is checked before dispatching the transformer. 7. Cable Box Finishing & Cork Sheet :- Finishing of Cable Box and proper fitting of Cork Sheet is checked before dispatch of the transformer. 8. Earthing :- Earthing is checked on every transformer before dispatch to prevent it from accidents. 9. Indoor/Outdoor :- Transformer is checked whether it is Indoor or Outdoor Transformer before dispatch. 10. Paint :- Proper Painting to overall transformer is checked ..

11. Breather Fittings :- Proper selection of Silica-Gel Breather according to rating of transformer and fittings of Silica-Gel Breather to the Breather Pipe is checked before dispatching the transformer . 12 . Leakage :- Oil leakages from transformer tank and valves are properly checked before Dispatch. 13. Wheeling Rod :- For Safety purpose of the transformer the Wheeling Rod is welded to the transformer tank to avoid accidents . 14. Tank Cover Bolt :- The tank cover bolt is welded properly to the transformer tank for safety of transformer from stealing accidents. 15. Seal Numbers :- Seal Numbers of the transformers are checked and verified before dispatching the transformer..

● Maintenance Procedure done on Distribution Transformer :-.

● Safety Guidelines followed in Industry :-. 1. Making use of Face Shield while doing Welding Work. 2. Making use of Rubber Gloves for protection against Injury, Hazards, Electric Shocks etc. 3. Keep spare nuts, bolts and other objects away from Working area so that they don’t fall into the Transformer Tank. 4. Always keeping the transformer and all of its components dry and free from any moisture or water..

5. To protect unskilled onlookers, setting up Caution Signs that warn people to keep away from DANGER. 6. Keep the power OFF when working on the transformer. Make sure there is zero electrical leakage or continuity between the current source and the system. 7. Checking the Electrical Transformer prior to Installation for any burning smell, faulty parts or abnormalities in continuity . 8. Any maintenance work must only be undertaken after the equipment is De-energized and tagged out and the circuit is shut down. This is necessary to ensure that there is no leakage of current or continuity between the current and the system ..

THANK YOU.