The invention provides an electrified replacement tool and method for a + / -800 kV circuit
strain insulator string. The electrified replacement tool comprises a
tower head end clamp, a wire end turnover board clamp, a wire end bearing support, hydraulic lead screws, mechanical lead screws and insulating pull rods. The
tower head end clamp is provided with a first
idler wheel and a
pulley. The wire end bearing support is provided with a second
idler wheel. The
tower head end clamp, the wire end turnover board clamp and the wire end bearing support are arranged at the two ends of the
strain insulator string to be replaced respectively and the tower head end clamp and the wire end turnover board clamp are connected through the hydraulic lead screws, the mechanical lead screws and the insulating pull rods, so that a load is transferred, the
strain insulator string is replaced, and installation is more stable; the first
idler wheel, the second idler wheel and the
pulley can provide supporting points for a main hauling cable and a steel
wire rope sleeve which are applied to the strain insulator string replacement process, so that the main hauling cable and the steel
wire rope sleeve are not likely to intervene with components or tools on a
transmission line and damage is reduced.