Sunday, November 1, 2015

Cable size and current carrying capacity

Cable size and current carrying capacity for XLPE insulated cable, non-armored, Twin or multicore cable is as below:-


Conductor operating temperature is 90 degree Celsius
Ambient temperature: 30 degree Celsius.

XLPE non armored cable


Cable size and current carrying capacity for XLPE insulated, Armored, Twin or multicore cable is as below:-
Conductor operating temperature is 90 degree Celsius
Ambient temperature: 30 degree Celsius. For air and 20 degree Celsius for ground for installations require to comply with BS: 7671

Cable size and current carrying capacity for XLPE armored cable


Correction factors:-
For Ambient temperature:
Ambient temperature in degree Celsius
Correction Factor
25
1.02
30
1.00
35
0.96
40
0.91
45
0.87
50
0.82
55
0.76
60
0.65
65
0.58
70
0.50
75
0.41
80


Ground Temperature
Ambient temperature in degree Celsius
Correction Factor
10
1.07
15
1.04
20
1.00
25
0.96
30
0.93
35
0.89
40
0.85
45
0.80
50
0.76
55
0.71
60
0.65
65
0.60
70
0.53
75
0.46
80
0.38

Soil Resistivity
Thermal resistivity Km/W
Rating factor for cables buried in Ducts
Rating factor for direct buried cables
0.5
1.28
1.88
0.8
1.20
1.62
1.0
1.18
1.50
1.5
1.10
1.28
2.0
1.05
1.12
2.5
1.00
1.00
3.0
0.96
0.90