What is the difference between HT and LT line?

Answer 1

ht cable that means voltage level is high , it is obvious that power is going to remain same ,so if voltage rises ,current has to be lowered .since current level is less in ht cable therefore size (dia) is less compared to l.t cable , (p=v.i),lt cable current rating is more and voltage rating is less

Answer 2

Actually, its the other way around. Conductors are smaller for HT lines than they are for LT lines. This is because high voltage requires less current to dissipate the same amount of power, and conductor size is a function of current, not power.

Remember: Power = voltage times current.

Perhaps you were thinking of the AWG size of the conductor? AWG, or gauge number, goes up as the physical wire size goes down.

Perhaps you were thinking in the distribution pattern. An HT line carries more power because it is divided more when you get down to the LT level. Power for power equivalent, however, the HT conductor is physically smaller than the LT conductor.

Answer 3

With increased voltage the line requires better insulation. The abbreviations, 'HT' and 'LT', stand for 'high tension' and 'low tension', respectively. In this context, 'tension' is a rather old-fashioned term, meaning 'voltage'. So, high-voltage transmission and distribution lines were termed 'high tension' lines, whereas low-voltage distribution lines were termed 'low-tension' lines. In the UK, 'high tension/voltage' lines are rated at line voltages of 11 kV, 33 kV, 132 kV, 275 kV, and 400 kV, whereas 'low tension/voltage' lines are rated at 400 V line-to-line (line voltage) and 230 V line-to-neutral (phase voltage).