We are currently using an underground supply of 11 kV with 300mm2, 3-core cable for transmission with 350A breaker on HT side for a span of nearly 7km. Now we want to alter a portion of that line which is about 1.5km to 11-kV overhead transmission line. Kindly guide me which type of conductor, insulator, poles height, span b/w poles, arrangement of conductor on poles etc practically BOQ for said job(we r working near sea so kindly take consideration for insulation failure due to moisture content)
