Page 87 - IS-Rayfast Catalogue - Issue 9, 2017

Wire and Cable
Custom Cable Designs
Technical Information
Multi-conductor cables

Wire Bundle Multiplication Factors Number of Wires Multiplication Factor 1
Equal Size Wires
1 1.00
The table right provides multiplication factors
for wire bundles of 1 to 61. To determine the 2 2.00 2
approximate diameter of a wire bundle when
3 2.16
the wires are all the same size, find the factor
4 2.41 3
for the number of wires in the bundle and
multiply the wire diameter by that factor. 5 2.70
6, 7 3.00 4
Calculation of Wire Bundle
8 3.60
Different Size Wires
9, 10, 11, 12 4.00
To determine the wire bundle diameter when 5
using wires of different sizes, follow steps: 13, 14 4.41
1. Determine the number of wires in the wire 15, 16 4.70 6
bundle.
17, 18, 19 5.00
2. Find the diameter of the wires in the Wire
and Cable section of this catalogue. 20, 21 5.31 7
3. Calculate the cable bundle outside 22, 23, 24 5.61
diameter by using the example below.
25, 26, 27 6.00
8
28, 29, 30 6.41
Example: A bundle of wires containing:
• 3 wires of 44A0111-22 (@ 1.19mm dia.) 31, 32, 33 6.70
• 5 wires of 44A0111-20 (@ 1.40mm dia.) 34, 35, 36, 37 7.00 9
• 1 wire of 44A0111-18 (@ 1.65mm dia.)
38, 39 40 7.31
10
41, 42, 43, 44 7.61
D = 1.2 √ (3 x 1.19 + 5 x 1.40 + 1 x 1.65 )
2
2
2
D = 1.2 √ (3 x 1.42 + 5 x 1.96 + 1 x 2.72) 45, 46, 47, 48 8.00
D = 1.2 √ (4.26 + 9.80 + 2.72) 49, 50, 51, 52 8.41 11
D = 1.2 √ (16.78)
53, 54, 55, 56 8.70
D = 1.2 x 4.10
D = 4.92mm 57, 58, 59, 60, 61 9.00 12
13
Resistance and Current Carrying Capacity
Conductor Size (AWG) Tinned Cu 30 28 26 24 22 20 18 16 14 12 14
Max Resistance Ohms/km @ 20ºC 356 225 135 86.0 53.2 32.4 20.4 15.8 9.9 6.6
15
Current Carrying Capacity (amps) 2.2 2.9 4.1 5.5 7.4 10. 14.0 15.5 21.0 28.0
Current carrying capacity for 30ºC rise above 20ºC ambient
16
Current Carrying Capacity Multiplying Factor for multicore cables of the same size
17
Number of Cores 2 3 4 7 9 12 15 18 21 24 27 30 37
18
Derating Factor 0.825 0.73 0.66 0.54 0.49 0.43 0.39 0.36 0.33 0.31 0.29 0.28 0.26

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