Page 70 - Power Cables Catalogue.pdf

TECHNICAL INFORMATION

0.6 /1 KV CABLES
CURRENT CARRYING CAPACITY

For cable installation in other conditions, the current rating can be determined by the use of various
rating factors given hereunder :

INSTALLATION IN GROUND

A. Factors for variation in ambient temperature and thermal resistivity of the soil.
Thermal Resistivity of the soil
K.m/W 0.7 1.0 1.5 2.5
Insulation Load Factor 0.7 1.0 0.7 1.0 0.7 1.0 0.71.0-
Type Soil Temperature ºC
10 1.16 1.05 1.05 0.98 0.95 0.91 0.86
15 1.14 1.03 1.02 0.95 0.92 0.89 0.84
20 1.12 1.0 1.0 0.93 0.90 0.86 0.81
X L P E 2 5 9 . 0 8 9 . 0 0 8 . 0 7 8 . 0 4 7 . 0 8
3 0 9 . 0 5 8 . 0 8 8 . 0 4 8 . 0 1 7 . 0 5
3 5 8 . 0 2 7 . 0 8 7 . 0 2
40 0.68
10 1.19 1.06 1.06 0.97 0.94 0.89 0.83
15 1.17 1.03 1.03 0.94 0.91 0.86 0.79
20 1.14 1.01 1.00 0.91 0.87 0.83 0.76
P V C 2 5 9 . 0 7 8 . 0 8 8 . 0 4 7 . 0 9 7 . 0 2
3 0 9 . 0 4 8 . 0 5 8 . 0 0 7 . 0 6 6 . 0 8
3 5 7 . 0 7 7 . 0 2 6 . 0 3
40 0.59

B. Factors for grouping in soil
Single core cables in flat formation
Clearence between systems: 7 cm.
Load Factor 7 . 0 0 . 1
Insulation Thermal Resistivity of the soil
Type K.m/W 0.7 1.0 1.5 2.5 0.72.5-
No. of systems in the trench
1 0.99 1.00 1.01 1.03 0.85
2 0.86 0.87 0.88 0.88 0.71
3 0.77 0.77 0.78 0.79 0.62
XLPE 4 0.73 0.73 0.74 0.74 0.58
5 0.69 0.70 0.70 0.71 0.55
6 0.67 0.68 0.68 0.69 0.53
8 0.64 0.65 0.65 0.65 0.52
10 0.62 0.63 0.63 0.63 0.49
1 0.98 1.00 1.01 1.02 0.85
2 0.86 0.87 0.88 0.89 0.71
3 0.77 0.78 0.79 0.79 0.62
PVC 4 0.73 0.74 0.74 0.75 0.58
5 0.70 0.70 0.71 0.71 0.55
6 0.68 0.68 0.69 0.69 0.53
8 0.65 0.65 0.65 0.66 0.51
10 0.63 0.63 0.63 0.64 0.49

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