Abstract: A telescoping robotic arm for temporarily supporting energized power lines to enable repair or replacement of transmission poles, crossarms, insulators and the like. The robotic arm is connectible to the boom of a service vehicle and is operable by remote control. The arm includes a boom adaptor sleeve for receiving the upper end of the boom, a frame pivotably coupled to the boom adaptor, and at least one telescoping arm coupled to the frame and adjustable between a retracted position and an extended position coaxial with the frame. An insulator stack and conductor holder are mounted on each of the telescoping arm(s) and the frame for releasably engaging a corresponding energized conductor. The angular position of the frame relative to the boom adaptor is adjustable to permit levelling of the robotic arm irrespective of the boom angle.