D
dojedar
Hi, I am reviewing the calculations for a 200A line with two 3 core 70 sq mm armoured cables, i.e. 2 cables per phase. These cables supplies to a 110KW pump and are installed direct buried along a trench with other 48 power cables in the form of 6 rows of 8 cables each row.
The cables have overheating and losing insulation resistivity. The calculations made had considered 5 cables installed on same row only. I understand this is wrong because there are 8 cables each row and should be applied ather rating factor for each layer. The installer, who made the cable sizing, says that overheating is produced by unbalanced currents on armour.
I have looking for references from BS 5467 standard trying to find the correct rating factors but I did not found anything by the moment. I appreciate if anybody have more information about this issue.
Regards
The cables have overheating and losing insulation resistivity. The calculations made had considered 5 cables installed on same row only. I understand this is wrong because there are 8 cables each row and should be applied ather rating factor for each layer. The installer, who made the cable sizing, says that overheating is produced by unbalanced currents on armour.
I have looking for references from BS 5467 standard trying to find the correct rating factors but I did not found anything by the moment. I appreciate if anybody have more information about this issue.
Regards