Question about 69kv power lines….?

Question

For a 69kv double circuit line, is it more efficient to use one pole holding both circuits or using two separate poles each holding one of the two circuits?

Answer 1

construction cost is less carrying the two 3-ph power lines in one pole, but if not laid in proper configuration, energy losses will be high. to lower construction cost, most of transmission line used one pole.

to minimize the energy loses, the two 3-ph abc power lines configuration should be a-b-c for the top and c-b-a for the bottom.

Answer 2

I have seen (both in books and in real-life) double 67-69 kV circuits (3-phase) on single aluminum poles so yes, it would be more efficient to put 2 circuits on a single pole.

I have never seen a double 69 kV circuit on wooden poles, though -- those have always been double poles tied-together at the top. My reference doesn't mention doubling up circuits on a single wooden pole.

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