Calculation of dimensions and weights of cables and wires structural elements

The diameter of a round stranded conductor is equal to the product of the wire diameter and the correction coefficient, that depending on the total amount and wire distribution in the CCC. Dс = Dпр × К.

Number of wires in the core	Coefficient	Number of wires in the core	Coefficient	Number of wires in the core	Coefficient
2	2,0	11-12	4,15	31-33	6,7
3	2,15	13-14	4,41	34-37	7,0
4	2,41	15-16	4,7	38-40	7,3
5	2,7	17-19	5,0	41-44	8,0
6-7	3,0	20-21	5,3	45-48	8,15
8	3,3	22-24	6,0	49-52	8,41
9	3,7	25-27	6,15	53-56	8,7
10	4,0	28-30	6,41	57-61	9,0

Example. 24×0,20 CCC diameter is equal to Dс = Dпр × К = 0,20×6,0=1,2 мм.

49×1,12 CCC diameter is equal to Dс = Dпр × К = 1,12×8,41=9,42 мм.

How to calculate the wire section of the CCC?

Solid conductor.

S = π × D² ÷ 4, where
π — the number Pi,
D – the wire size.

Stranded conductor

S = π×D²×п÷4, where
π — the number Pi,
D – the wire size,
п – number of wires in the core.

How to calculate the mass of the round CCC?

m = π×d²×n×n1×µ×K×K1÷4, where
π — the number Pi;
d – the wire size;
n – number of wires;
n1— number of cores;
µ — the density of the core material (copper 8,89 g/cm³, aluminum 2,7 g/cm³);

К – the coefficient which takes into account the wires twisting take-up in the core (for multi–wire cores);

К1 – the coefficient which takes into account the wires twisting take-up in the cable (for round cables).

Note:

For solid conductor К=1,0;
For flat cables К1 =1,0;
For flexible multi-wire bunchy stranding with the wire section up to 2,5 mm² К×К1= 1,01;
For flexible multi-wire bunchy stranding with the wire section up to 4,0 mm² and above К=1,034, К1 = 1,03.

How to calculate the insulation mass in a cable?

m = π×(⌀fc+t) × t × µ × n1 × K1 × Kф, where

π — the number Pi;
⌀fc – the core size;
t – the radial thickness of the insulation;
µ — the density of the insulation (check with the material supplier, for PVC И40-13 –1,32 g/cm³, Polyester – 0,92 g/cm³);
n1 – number of cores;
K1 – the coefficient which takes into account the wires twisting take-up in the cable. For cords of any section views, and also for wires and flexible cables К1 = 1,034;
Kф – the coefficient which takes into technology factors (Kф= 1,02).

How to calculate the weight of the cable sheath?

The round cables with a free laying sheath (tube).

m = π × (⌀fc – Т) × T × µ × Kф

The round cables with a laying sheath and filling the gaps between the cores (compression laying on).

Q – the area of space between the cores,
for three-conductor Q= 0,04 ⌀ins;
for four-conductor Q= 0,22 ⌀ins;
for five-conductor Q= 0,54 ⌀ins.

Double-conductor and three-conductor flat cables with a free laying sheath (tube).

m = Т(π×(⌀ins+Т)+2 ⌀ins × (n1 — 1))× µ × Kф, where

π — the number Pi;
⌀fc – the diameter of the flexible cable;
⌀ins – the insulation diameter;
T – the radial thickness of the shell;
µ — the density of the shell material (clarify with the material supplier);
n1 – number of cores;
K1 — the coefficient which takes into account the wires twisting take-up in the cable. For cords of any section views, and also for wires and flexible cables К1 = 1,034;
Kф — the coefficient which takes into technology factors (Kф= 1,02).

How to choose the radial thickness of the insulation and sheath?

The requirements for the material, the specific values of the radial thicknesses of the insulation and the sheath of the cable product are set out in the reference documentation for a specific product (GOST or TR for cable). In some cases, the reference documentation provides a reference to GOST 23286-78 "Cables, wires and cords. Standards for insulation thicknesses, sheaths and voltage tests".