Useful Formulae for Copper Conductors

 

Weight kg/km	= d² x n x k x 6.982
Resistance, ohms/km	= 21.95 x k ÷ d² ÷ n
Cross section, mm²	= d² x n x 0.785
Conductor, diameter, mm	= vn x d x 1.15 (1.30 for ropes)

 

d = single wire diameter,mm
n = number of wires
k = laying up factor - bunch 1.01, strand 1.02, rope 1.04