The insulation layer of the paper-covered wire refers to the wire wrapped around the cable paper. The insulation of the paper-covered wire has at least 3 layers of wrapping paper tape. When more than 3 feet, the innermost layer and the outermost layer should be covered and wrapped, and the rest can be wrapped with a gap of no more than 2mm. When the width of the paper tape is 9.5 mm and above, the clearance does not exceed 3mm.