Method for testing potential to ground of manually wound insulation of generator

The present invention provides a method for testing potential to ground of manually wound insulation of a generator based on an apparatus for testing potential to ground of manually wound insulation of a generator. The method comprises the steps of: S1, wrapping a manually wound insulation end of a generator stator with a tinfoil; S2, installing a sharp-point conductor onto a connecting conductor at the top of a high-voltage insulation support bar and testing potential to ground of the manually wound insulation end of the generator stator; S3, judging whether the potential to ground of the manually wound insulation end of the generator stator is within a preset range, executing S4 if the potential to ground of the manually wound insulation end of the generator stator is within the preset range, and otherwise, installing a sphere-shaped voltage sensor or a cylinder-shaped voltage sensor onto the connecting conductor at the top of the high-voltage insulation support bar to perform fault point positioning; and S4, installing a plate-shaped voltage sensor onto the connecting conductor at the top of the high-voltage insulation support bar and testing the potential to ground of manually wound insulation of an involute part. The method of the present invention solves the problem that a test technology in the prior art cannot test the potential to ground of manually wound insulation of an end involute part.