Aluminium Strip for Transformer Winding
Flat Aluminium Strip / Aluminium Flat Strip in China
Transformer strip is used in transformers for electrical engineering and in power distribution, which means in power plants and substations, in local distribution networks, in wind power, industrial plant and the power adaptors belonging to electronic devices.
Transformer Aluminium Foil Specification
Transformer Aluminium Foil
Henan Signi Aluminium Co,Ltd
This Specification specifies aluminium foil used as conductors for transformers
( hereinafter abbreviated as “foil” ).
The applicable dimension of foil shall conform to table 1.
|Unit : mm|
|Thickness||0.3 to 2.4|
|Width||25 to 1250|
3.Outline of the quality
3.1 The chemical composition of shall conform to table 2.
|Unit : weight %|
3.2 Mechanical properties and electric conductivity shall conform to Table 3.
|Bending 180 buckling inside radius||
% at 20°C
|Over 0.3 to 0.5||Less than 75||25min.||Close contact||62.5min|
|Over 0.5 to 0.8||Less than 75||30min.||Close contact||62.5min.|
|Over 0.8 to 1.3||Less than 75||35min.||Close contact||62.5min.|
|Over 1.3 to 2.0||Less than 75||35min.||Close contact||62.5min.|
|Over 2.0 to 2.4||Less than 75||35min.||Close contact||62.5min.|
3.3 Dimensions shall conform to Table 4 which indicates dimensional tolerances.
Unit : mm
|Thickness||Tolerance in thickness||Tolerance in width|
|Guaranteed value||-||25 to 300||
|Over 0.3 to 0.5||±0.02||±0.3||±0.5||±1.0|
|Over 0.5 to 0.8||±0.03||±0.3||±0.5||±1.0|
|Over 0.8 to 1.3||±0.04||±0.3||±0.5||±1.0|
|Over 1.3 to 2.0||±0.04||±0.3||±0.5||±1.0|
|Over 2.0 to 2.4||±0.05||±0.3||±0.5||±1.0|
3.4 Inside diameter, outside diameter and unit weight shall conform to Table 5.
|Inside diameter||Outside diameter||Remarks|
|150mm, 305mm||1200mm||Paper core. Special demand could be talk.|
Note:The classification of Table 5 may be disregarded if particularly specified otherwise.Or Depeneding on customer’s requirements.
3.5 Coil’s deformation shall conform to Table 6.
|Deformation of inside diameter||(Max. - Min.) < 10|
3.6 Coil winding
Coil winding shall be as follows.
3.7 Interphase insulation foil
The interphase insulation foil for aluminum foil protection is unnecessary.
4. External Appearance, ETC.
(1) The surfaces of foil shall be clean and smooth and shall be free of noxious defects for use such
as wrinkles, distortion and flaws. The foil edge in particular shall be free of flaws.
(2) The foil shall be free of attachment of substances which are noxious for use such as oil, grease,
soapy water and metal powder.
(3) The edge of foil shall be in accordance with following conditions.
Precision slit :
all sizes (schematic)
max. burr size 3% of thickness or max. 0.05mm.
The edge quality shall comply to table below.
|Sectional shapes of sheet edge|
5. Tests and Inspections
1) Inspection of external appearance
Defects in the quality specified in item 4 shall not be found as a result of visual inspection and inspection by hand feeling.
2) Chemical test
The test result shall conform to GB/T3190.
3) Tensile strength and Elongation test
The test result shall conform to GB/T228.
4) Electric conductivity test
The test result shall conform to Appendix 1.
5) Dimensional inspection
Measurement of thickness and width shall be taken using micrometer, slide calipers, tape measure, straight-edge, etc.
Packaging shall be made that the center axis of roll shall be made on the horizontal direction
Both eye to wall and eye to Sky packing are available for us.
Moisture proof packaging shall be made for delivery for convenience of carriage and handling and
also in order not to allow occurrence of uncoiling, rusting, damage, etc. at the occasions of storage,
carriage, warehousing, etc.
7. Test Record
Inspection and tests described item 5 shall be carried out on each.
Aluminium foil size and shall be carried out on each delivery.
Test record shall include the result of the tests and inspection and shall be submitted with the invoice.
The following matters shall be marked by a suitable method at easy-to-see places of each foil
1) Type and grade
2) Dimensions and quality ( at the front and the opposite side )
3) Month of production and serial number
4) Manufacturer’s name
5) Gross Wt.
6) Net Wt.
|Machine name||Slitting thickness|
Method for measurement of electric conductivity
The test specimen shall be of a length of 300 mm or longer as a rule. The electric resistance shall be
measured in a constant temperature chamber of 15-20°C.
…in case of mean sectional area method
…in case of superposing method
Where; Rt: Electric resistance of specimen at t°C (Ω)
1 : Length of electric resistance measuring section (m)
m : Weight of specimen (g)
2 : Length of specimen (m)
a : Mean sectional area of specimen (mm2)
A : 0.017241
C : 0.04655 (assuming the specific gravity as 2.7)
α20 : Constant mass temperature coefficient at 20°C
Transformers have hearts – hearts made of coils of wound copper. The principle is always the same, whether in large-scale transformers, power transformers, oil distribution or cast resin transformers.
Typical areas of use
Here are some of the areas in which transformer strip is used:
Power and electrical engineering