CRGO Transformer Cores

The Slitting Machine gives 18 adjustable strip widths. Tool geometry is of critical importance for eliminating burrs of CRGO.

CUTTING ACCORDING TO LENGTH (CRGO)

AUTOMATIC METHOD OF PROCESSING CRGO POWER TRANSFORMER LAMINATION 
Evergreen uses the newest, computerized version of Cut to Length Machines in order to produce Step Lap Transformer Laminations Cores.

MANUAL METHOD USED FOR DISTRUBUTION CRGO TRANSFORMER LAMINATION. 
The SECOND stage of the CRGO Lamination manufacturing process is "Shearing" at 45 or 90 as required by the customer. Strict tolerances are maintained (as per the tolerance chart) and a unique three point location method ensures accuracy in dimensions in terms of angle and length. Burs are controlled by ensuring the blades are always sharp. Continuous line inspection ensures all parameters are strictly maintained within acceptable limits.

The THIRD step of CRGO Lamination manufacturing process is to fabricate "V-Notch" or holes at per customer's design. Accuracy is utmost importance and specially designed jigs and fixtures ensure that all dimensional tolerances specified by the customer are maintained.

STRESS RELIEF ANNEALING

The FOURTH step of the manufacturing process of CRGO Transformer Lamination is to deburr and stress relief anneal the material by other health annealing furnace. This is done as per the mill's specification at 820 º C for a few minutes depending upon the thickness and grade of CRGO material.

TESTING

Final Inspection of CRGO Lamination for Manufacturing Tolerences as per International Standard OR as Per Customer Requirement. Checking of Core Losses on the Finished CRGO Lamination and No Load losses on CRGO Built Up Cores. Issue a Test Certificate for Every Despatch.

PACKING

We are able to deliver CRGO lamination as leg or sheet packet, according to your packing requirements, inside of wooden box or on the pallets.

Production Processes For Crgo (Grain Oriented Steel) Toroidal Transformer Cores
SLITTING

CRGO Electrical steel comes in the form of wide coils having widths of 750 mm to 1000 mm. These coils are to be slit in various widths in steps ranging from 10 mm to 100 mm.

WINDING

These slit coils of CRGO are wound on semi automatic winding machine as per the dimensions given by our customers.

SPOT WELDING

On winding the CRGO Toroidal cores to the exact size the start and finished ends of the core are spot welded on spot welding machine.

STRESS RELIEF ANNEALING

During the winding process of CRGO, severe stresses are induced in the gains of the raw material. Theses stresses are relieved in our specially designed annealing furnace equipped with automatic temperature controller, circulating fan and inert atmosphere. The annealing cycle (at 800°C) improperly controlled to get uniform and best annealing results.

TESTING

Since the CRGO electrical properties of cores are very critical, every core is tested on a specially designed test bench. The ampere turns/cm (magnetization current) are measured on every core to ensure that they are within the specified limits.

PAINTING

After testing the 'PASSED' cores are painted with N.C. paint to prevent the CRGO Toroidal cores from corrosion.

PACKING

The Electrical Properties of CRGO Toroidal cores are very sensitive to bad handling during transit. We take great care while packing the cores in wooden boxes with cushioning material to prevent stresses on the cores during dispatch.