Classification of Underground Cables – LT vs HT vs ST vs EHT vs ESVC Cables
Underground Electrical cables can be classified in two ways. The first type of classification is based on insulating material used in their manufacturing, while the second type is based on the voltage for which they are manufactured. The first classification of classification is not quite popular and is only applicable when specific applications of usage are considered, the classification based on voltage is generally preferred. Based on this classification cables are divider into five groups.
- Low-tension (L.T.) cables — upto 1000 V
- High-tension (H.T.) cables — upto 11,000 V
- Super-tension (S.T.) cables — from 22 kV to 33 kV
- Extra high-tension (E.H.T.) cables — from 33 kV to 66 kV
- Extra super voltage cables — beyond 132 kV