CRGO Core/Cut Laminations

CRGO steel is imported in the form of mother coils from reputed steel producers in USA, Japan, Korea, Germany, China, Russia etc. Each coil conforms to the specifications of Bureau of Indian Standards of quality (IS 3024). Each lot of raw material is accompanied with Mill Test Certificate (MTC) and other relevant chain of documents that can be produced at customer’s request.

The core of the transformer is used to carry magnetic flux from primary winding to secondary winding. In this process some unwanted current (Eddy currents) are developed in the core, which is responsible for heat losses in the core. To increase the efficiency of the transformer it is necessary that there should be maximum flux linkage from primary to the secondary and losses minimized. This is done by using CRGO Lamination for construction of the core

Processing of Transformer lamination requires high degree of precision for which highly customized CNC machine are required. Equipped with 3 automatic CNC cut to length machines and 2 slitting lines, we can process 3000MT CRGO per annum at ease. Our CNC Cut to Length machines are able to process lamination in various shapes and sizes with 90°/75°/45° angle cutting. The lamination can be cut to different dimension ranging from 25 mm to 1050 mm width and 100 mm to 5000 mm

We can process transformer lamination in the below form :
Conventional Designs
Horizontal Step Lap
Vertical Step Lap 789yu
Reactor Cor

CRGO Core/Cut Laminations

We manufacture complete CRGO Core Assembly for the Distribution and Power transformers of upto 20 MVA. The Core Assembly is extensively tested for no load losses while they are packed with utmost care and are ready for insertion of LV and HV coils. By choosing our built cores, it facilates in labour cost and no wastage of material. With the latest testing facility and modern infrastructure, we can achieve desirable No-Load Losses with limited excitation current and over-saturation

General Physical and Mechanical Properties of CRGO Steel
Density	7.65 g/cm3
Thickness of sheet	0.23 – 0.35 mm
Silicon content	3-4 %
Yield Point (relative to rolling direction)	0 degrees • 330 N/mm2 90 degrees • 355 N/mm2
Tensile strength	0 degrees • 348 N/mm2 90 degrees • 412 N/mm2
Elongation	0 degrees • 11% 90 degrees • 31%
Number of bends	0 degrees • 21 90 degrees • 15
Hardness (HV)	204
Stacking factor	> 96%

CLASSIFICATION OF CRGO BY GRADE
Grade (Conventional Nomenclature)		Thickness (mm)	Max. Core loss (W/kg) 50Hz
			@1.5T	@1.7T
23HP85	23ZDKH	0.23	0.6	0.85
23HP90	23M0-H	0.23	0.64	0.9
23HP95	23M0-H	0.23	0.66	0.95
23HP100	23M0-H	0.23	0.68	1
23CG110	M3	0.23	0.7	1.1
27HP95	27ZDKH	0.27	0.66	0.95
27HP100	27M0-H	0.27	0.7	1
27HP110	27M0-H	0.27	0.78	1.1
27CG120	M4	0.27	0.85	1.2
27CG130	M4	0.27	0.9	1.3
30HP105	30M0-H	0.3	0.75	1.05
30CG130	M5	0.3	0.9	1.3
30CG140	M5	0.3	0.95	1.4

TOLERANCE CHART
Attribute	Attribute Range	Tolerance
Width	0 – 100 mm	+0.00 / -0.15 mm
	100 mm – 230 mm	+0.00 / -0.20 mm
	230 mm – 400 mm	+0.00 / -0.30 mm
	400 mm – 750 mm	+0.00 / -0.50 mm
Length	0 – 350 mm	+0.00 / -0.30 mm
	350 mm – 1,000 mm	+0.00 / -0.60 mm
	1,000 mm – 2,000 mm	+0.00 / -1.00 mm
	2,000 mm – 3,000 mm	+0.00 / -1.50 mm
	3,000 mm – 4,000 mm	+0.00 / -2.00 mm
Thickness	0.23 – 0.27 mm	+/- 0.025 mm
Thickness	0.30 – 0.35 mm	+/- 0.030 mm
Mitering Angle	45 degrees	+/- 5 minutes
Burr Height	0.18 – 0.23 mm	10 microns
	0.23 – 0.30 mm	15 microns
	0.30 – 0.35 mm	20 microns
Wave Factor	Material width > 150mm	Max. 1.5% of width
Wave Factor	Flatness deviation	Max. 1.5% of width
Edge Camber	Material width > 150mm	Max. 0.8 mm for 1.5m
Edge Camber	Material width > 150mm	Max. 0.8 mm for 1.5m
Hole Dimension	Up to 34 mm	+/- 0.15 mm