FORMULA TO CALCULATE DIAMETER OF BUNCHED ELECTRICAL CORES

For cables of the same diameter
There is a factor
1 cable Factor is 1
7 cables the factor is 3
19 cables the factor is 5
37 cables the factor is 7
61 cables the factor is 9
Cables all of the same diameter, formed around a central single core follow the "rule of 6"
the first layer is 6 plus the inner core is 7 (the 7 wire assembly is 3 cable diameters in diameter)

the second layer contains 6+6 plus the 7 below it, so it has 19 total cables and is 5 cable diameters in diameter.

The third layer is 6+6+6 or 18 cables plus 19.... and so on

hopes this helps

Wilber

I don't know if this is what you are need or not but take a look:


David Baird
mrbaird@hotmail.com

Sr Controls Engineer

EET degree.

Journeyman Electrician.

If all the strands are the same diameter it is very simple.

D = d*(2*LAYERS-1)
with d the strand diameter & LAYERS the number of strand layers. Typically the number of strands N equals
N = 1+3*LAYERS^2-3*LAYERS.

For example a N=37 strand cable with d=.1466" has
LAYERS = 4 because 37=1+3*4^2-3*4, and
D = .1466*(2*4-1) = 1.0262" the outter dia of the cable.

John Alexiou
Alcoa - SAG10/Vibrec Development.
john.alexiou@alcoa.com