Geometric mean radius factor

The geometric mean radius factor depends on the construction of the conductor, the number of stranded wires and the compaction of the strand.

The IEC 60287-1-3 Ed.1.0 Table 1 lists values factor K

Values in the standard are for 1 (solid), 3, 7, 19, 37, 61, 91, and 127 number of wires, the other values are interpolated.
The given values are applicable to non-compacted circular conductors.
The equation for a single solid wire is $\exp(\frac{-1}{4})$ being equal to 0.77880078...
For compacted conductors the value for solid conductor is used (0.7788).
Values for hollow conductors are dependant on the inner and outer diameter of the conductor as by example in annex B of the the IEC standard.
No information was given for shaped conductors, the same values are taken as for non-compacted circular conductors.

Symbol

$K_{GMR}$

Formulae

$e^{-\left(\frac{1}{4}\right)}$

Related

$n_{cw}$

Used in

$GMR_c$

Choices