Formulas
Technical data for constructions not listed, you can calculate using the following formulas (IEC 317-11)
Calculation of the nominal overall Diameter
| ||||
| where | D | Nominal bunched wire Diameter | ||
| p | packing factor | |||
| n | Number of single wires | |||
| d | Nominal overall diameter of the single wire | |||
| Tables | ||||
Cross-section of the conductor
| ||||
| where | q | Nominal cross-section (conductive material) | ||
| dnom. | Nominal bare diameter of conductor | |||
| n | Number of single wires | |||
| d | Nominal outer diameter of a single wire | |||
Calculation of the litz resistance
For the calculation of the resistance, the values of the resistance have been taken from IEC 60317-0-1.
| nominal resistance | nominal resistance of single wire x k1 | |||||||||||
| = |
| |||||||||||
number of single wires | ||||||||||||
| minimun resistance | minimum resistance of single wire x k1 | |||||||||||
| = |
| |||||||||||
number of wires | ||||||||||||
| Maximum resistance | ||||||||||||
| a) Number of wires up to and including 25 | ||||||||||||
| maximum resistance | maximum resistance of single wire x k1 | |||||||||||
| = | ||||||||||||
number of single wires | ||||||||||||
| b) Number of wires over 25 | ||||||||||||
| maximum resistance | maximum resistance of single wire x k1 x k2 | |||||||||||
| = |
| |||||||||||
number of single wires | ||||||||||||
| The factor k1 is 1,02 and is taken because of the decrease in length due to bunching | ||||||||||||
| ||||||||||||
| The factor k2 is 1,03 and is taken because of the broken ends which may occur. | ||||||||||||