| Andrew Yule & Company Limited | ||||||||||||||||||||||||
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COMPANY PROFILE Andrew Yule is a Government of India enterprise - a multiproduct, multidivision conglomerate having a group turnover exceeding Rs. 400 crores. The spectrum of products of the 'Yule' group range from Tea to Transformers and Lube Oils to Industrial Belts. The group has eleven collaborations with world leaders in seven countries. In effect, it has many technologies under one name - 'Yule'. The T&S (Chennai)Unit functions under the Electrical Division of the Andrew Yule Group. This unit was established in 1957 with technical collaboration from Dominit Werke of West Germany. Initially the Unit was engaged in the manufacture of Power and Distribution Transformers upto 66 kV class. It became a member of the Yule family in 1984; and then on, engaged in the manufacture of 132 kV class Transformers & medium High Voltage Switchgears. THE RANGE OF PRODUCTS Power & Distribution Transformers upto 50 MVA 132 kV Convertor Transformers upto 20 MVA 33 kV Furnace Transformers upto 15 MVA 33 kV Dry type Transformers upto 15 MVA 33 kV Dry type Transformers upto 33 MVA 11 kV, class 'C' Flame Proof Transformers, Earthing Transformers Series and Shunt Reactors, Auto Transformers and twin core voltage regulating Transformers. SHORT CIRCUIT CAPABILITY Transformers have to withstand short circuit forces in service, which give rise to severe mechanical and thermal stress. Meticulous design, right selection of materials, controlled manufacturing process, ensure short circuit withstand capability. Andrew Yule has successfully conducted this most onerous test, viz., the short circuit test on wide range of transformers as listed below, at CPRI, Bhopal. The successful short circuit test on 25 MVA, 132 kV class transformer is the pioneering achievement in India. � 100 kVA 33/0.433 kV � 1000 kVA 11/0.433 kV � 1600 kVA 33/11 kV � 1600 kVA 33/0.433 kV � 3000 kVA 33/3.3 kV � 3150 kVA 33/11-6.6 kV � 5000 kVA 33/11-6.6 kV � 6300 kVA 33/11 kV � 10000 kVA 33/11 kV � 12500 kVA 66/11 kV � 16000 kVA 66/11 kV � 25000 kVA 132/33 kV | |||||||||||||||||||||||
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MAIN FEATURES OF TRANSFORMER CORE Core laminations are of cold rolled grain oriented silicon sheet steel. Each lamination is coated on both sides with Carlite' insulation. Core assembly is of interleaved construction with mitred joints to reduce Iron loss and magnetizing current. The limb laminations are securely bonded with special adhesive and the yoke laminations are clamped together with mild steel channels. This reduces vibration and noise. For large cores, the limb laminations are held together by means of fibre glass bands coated with epoxy resin. The bottom and top core clamping channels are clamped together by means of Tie rods/plates. These keep the windings in its place and serve to transfer the deadweight of core and windings from bottom to top clamp. Large cores are provided with cooling ducts. WINDING Continuous disc, helical, spiral or cross over type of windings are employed depending the current and the voltage. Conductors are of paper insulated, high conductivity copper. Inter disc/layer cooling ducts are selected to ensure minimum temperature gradient and to keep the host spot temperature with limits. High voltage coils are of inter leaved disc type to improve initial surge voltage distribution. Static condenser rings are also provided to have uniform surge distribution. Transpositions are made when multiple conductors are in parallel and when the number of conductors are further large, rotary transposition technique is adopted. This ensures less losses due to circulating current. COIL PROCESSING All the wound coils prior to assembly are pre-shrunk in hot air ovens at a temperature of about 90�C with spring pressure. This ensures a constant and continuous pressure throughout the drying cycle on the windings. This treatment eliminates any further shrinkage of the windings and thereby providing strength to withstand the Electro-magnetic forces under severe short circuit conditions. CONNECTION Main and tapping leads are paper covered conductors and are brazed to the winding conductors. The leads are well supported. TANKING The active part is carefully lowered into the tank through the guides provided for the purpose and locked properly to withstand transport jerks and jolts. PROCESSING Drying and impregnation process is carried out under vacuum. The vacuum is achieved in autoclave or in its own tank. Temperature is maintained at 100�C for a period depending on the size of the transformer. The vacuum process is continued till all traces of water is removed. Hot degassed oil is then allowed into the tank and the insulation gets impregnated with oil. TESTS All the transformers are subjected to routine tests as per IS 2026 or to any other International Standards. Any other type and special tests as per contract can also be carried out. PAINTING The tanks and other external surfaces are blast cleaned to remove rust and scale and applied with red oxide primer. Two coats of standard enamel paint is applied. If application demands, alternate paint system like epoxy are adopted to take care of saline and heavily polluted atmosphere. QUALITY ASSURANCE The Quality Plan consists of all the Quality Control measures and ensures that the products supplied meet the requirements as per specifications and application requirements. These checks are carried out at all stages of operation such as materials, processes, assembly, packing and despatch. The company's quality plan has been approved by Tata Consultants, Mecon, NTPC, NHPC, BHEL and others. Quality records are maintained for each transformer manufactured. SALES AND SERVICE The company has a well knit sales and service team in all the four regions of the country to offer prompt service to the customers. ENGINEERING - RESEARCH & DEVELOPMENT The design and manufacturing techniques are under constant review by our R & D wing and the latest development in materials and processes are studied in detail and implemented. All our design and drawings are through computer systems and are constantly updated. | |||||||||||||||||||||||
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CUSTOMER PROFILE | � All State Electrical Boards � NHPC, NTPC; � DESU, DVC, DAE � Steel Plants - BHEL, BSP, RSP, Bokaro, SSP � Coal Mines � Railways � IOCL, HPCL & other Industries ANDREW YULE & COMPANY LIMITED (A Government of India Enterprise) Electrical Division Transformers & Switchgear Unit 5/346 Old Mahabalipuram Road Perungudi, Chennai - 600 096. Tel: 4961650, 4960595/010/121/793/528 Fax: 044- 4960903, Telegram: "TRANSWITCH" email: [email protected] HEAD OFFICE: 'YULE HOUSE', 8, Dr. Rajendra Prasad Sarani, Calcutta - 700 001. Phone: 033 - 2428210, 2428550 Fax: 033 - 2425477, 2422943 REGIONAL OFFICES DELHI 401-402-504 Lakshmi Bhavan 72, Nehru Place New Delhi - 110 019. Ph: 011 - 641 3279, 641 8168 Fax: 011 - 6422172 MUMBAI 32, Ramjibhai Kamani Marg Ballard Estate Mumbai - 400 038. Ph: 022 - 2619081-83 Fax: 022 - 2625143 CALCUTTA 14, Mayurbanj Road Calcutta - 700 023 Ph: 033 - 4791761-63 Fax: 033 - 4796347 Powered by: [email protected]
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