 PROCESS
CRGO LAMINATIONS FOR TRANSFORMERS :-
• Sample Testing of the Raw Material :- The sample is drawn from the coil at random and Epstien Square test is conducted on the sample of 1 kg drawn from the coil at random and matched with the test certificate provided by the supplier.
• Slitting :- The CRGO steel is received in the form of Coil and can be slited in the minimum width of 5 mm and multiples of 5 mm. The cutters are frequently grinded to control the burr level.
• Shearing :- The slited coil are sheared in the treadle shearing machine at an angle of 45 Deg. & in case of mitered core and 90 Deg in case of Rectangular Core. Utmost care is taken in grinding of the blades at specific interval of time in order to minimize the burr level not exceeding than 10 micron.
• V-Notching :- The process of V-Notching in the yoke plates of the stacked laminations are carried out in semi automatic power presses using dies made of tungsten carbide for achieving almost zero burr level.
• Stress Relieving Annealing :- During the course of process the stresses developed in the stacked laminations tend to increase the losses and magnetizing current of the core. This is relieved by subjecting the laminations in Roller Hearth Stress Relieving Annealing Furnace.
• Testing :- Random tests are conducted on sample of the CRGO laminations for measurement of losses, insulation resistance, bend test, burr level etc.
• Packing :- The CRGO Laminations are packed on the wooden pallets and covered by the water proof hessian cloth duly strapped in order to avoid damage to the core edges.
CRGO CORE ASSEMBLY :-
The CROG laminations are stacked to form the Core Assembly as per the design given by the customer. The core laminations are stacked to form Core Assembly held rigidly by steel frame work clamped together to prevent any kind of vibration. The top and bottom yoke clamping channel are tight together with Tie Rods duly insulated. The core assembly is provided with lifting lugs suitable for lifting the complete core and coil assembly of the transformer without transmitting the stresses to the laminations.
TORROIDAL & RECTANGULAR CORE :-
The slit coils are wound on the winding machine as per the size ( OD, ID, HT) given by the customer.
• Spot Welding :- The starting and finishing end of the core are spot welded with the help of spot welded machine.
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Annealing :- The Torroidal & Rectangular Core are annealed in a pit type furnace with auto temperature controller in inert atmosphere. The cycle is so controlled to achieve the uniform results in the core.
• Painting / Varnish :- The core are painted/varnished to prevent the core from rust/corrosion.
• Testing :- The electric properties of each and every core is tested in a specially designed testing bench to ensure the core being within the required electrical parameters.
• Packing:- The core are packed in wooden boxes properly cushioned in order to avoid any kind of stress.
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