BS EN 60740-1:2005

1 Scope
2 Normative references
3 Terms, definitions and symbols
4 Materials and lamination thicknesses
   4.1 Materials
   4.2 Nominal lamination thickness
   4.3 Minimum stacking factor
5 Designation of laminations and lamination strips
   5.1 Specified complete shapes
        5.1.1 Lamination outline shapes
        5.1.2 Specified shape with lamination strips
   5.2 Lamination strips for specified shapes
        5.2.1 Lamination strips for yokes
        5.2.2 Lamination strips for limbs
   5.3 Lamination strips for non-specified laminations
6 Packing and marking
7 Electrical tests
   7.1 General
   7.2 Core constants
   7.3 Magnetic path length
   7.4 Core cross-section
8 General conditions for electrical measurements
   8.1 Atmospheric conditions
   8.2 Test coils
   8.3 Test cores
   8.4 Harmonic content of the voltage
9 Measurements at high field strength
   9.1 General
   9.2 Measurement of power loss
        9.2.1 Power loss for single-phase cores
        9.2.2 Power loss for three-phase cores
   9.3 Measurement of total apparent power
        9.3.1 Total apparent power for single-phase cores
        9.3.2 Total apparent power for three-phase cores
10 Measurements at low and medium field strength
   10.1 General
   10.2 Measurement of amplitude permeability
11 Preferred ranges of laminations
12 Dimensions and tolerances
   12.1 Dimensions
   12.2 Tolerances
   12.3 Symmetry tolerances
13 Dimensions and effective parameters
   13.1 General
   13.2 Lamination strips Type YS
   13.3 Laminations Type YEI 1
   13.4 Laminations Type YUI 1
         13.4.1 Lamination outline shapes Type YUI 1
         13.4.2 Lamination strip shape Type YSUI 1
   13.5 Lamination Types YUI 2
         13.5.1 Lamination outline shape Type YUI 2
         13.5.2 Lamination strip shape Type YSUI 2
   13.6 Lamination Types YEx 2, YEE 2 and YEI 2
   13.7 Lamination Types YEE 2-..L
   13.8 Lamination Types YEx 3, YEE 3, YEF 3,
         YEI 3 and YEL 3
   13.9 Lamination Types YEx 4, YEE 4 and YEF 4
   13.10 Laminations Type YM 1
14 Electrical characteristics for materials
15 Specific total apparent power for laminations
16 Specific power loss for laminations
17 Mechanical characteristics for laminations
   17.1 General appearance and conditions
   17.2 Cut and punch edge
   17.3 Camber
   17.4 Distortion
   17.5 Bending
   17.6 Insulation
   17.7 Welding
Annex A (informative) Conversion of polarisation and field
                      strength into specific total apparent
                      power
A.1 Specific total apparent power from polarisation and
    field strength
A.2 Equations for the curves of the magnetic materials
    A.2.1 Specific reactive power
    A.2.2 Specific reactive power of the material
    A.2.3 Specific reactive power of the air gap
    A.2.4 Specific power loss
    A.2.5 Specific total apparent power
A.3 Constants for non-oriented silicon steel C 21
A.4 Specific reactive power and specific power loss for
    non-oriented silicon steel C 21
    A.4.1 Specific reactive power
    A.4.2 Specific power loss
A.5 Constants for grain-oriented silicon steel C 22
A.6 Specific reactive power and specific power loss for
    grain-oriented silicon steel C 22
    A.6.1 Specific reactive power
    A.6.2 Specific power loss
A.7 Influence of the shape on the electrical characteristics
    for grain-oriented silicon steel C 22
Bibliography

Defines the characteristics of laminations normally used as cores for transformers and inductors

IEC 60740-1:2005 specifies the characteristics of laminations. Their preferred use is cores for transformers and inductors. The laminations are made of sheets and strips of magnetic materials, specified in IEC 60404-8-4 and IEC 60404-8-7. The main changes are listed below:
a) ranges with lamination strips YS, YSUI 1, YSUI 2 and laminations YEE 2-..L added;
b) range YEI 1 extended at the above end;
c) ranges YED 2, YEF 2, YEL 2, YES 2, Type YM 1-5a and YM 1-7a cancelled;
d) national designations cancelled;
e) electrical characteristics for the laminations specified;
f) mechanical characteristics for laminations added;
g) holes added for lamination types YEI 1, YUI 1, YUI 2, YM 1;
h) in Annex A, a conversion of the polarisation J and the field strength H in a specific total apparent power is defined. For the characteristics of the reactive power and the power loss, equations and constants are specified.