Taped Insulation

Insulation of helically wound tapes applied over a conductor or over an assembled group of insulated conductors. When successive convolutions of a type overlie each other for a fraction of the tape width, the taped insulation is lap wound. This is also called positive lap wound. A tape that is applied so that there is an open space between successive convolutions is called either an open butt wound or a negative lap wound. Where there are multiple layers of tape indexing refers to the fact that they are started a certain distance from each other along the axis of the cable to assure full coverage. When a tape is applied so that the space between successive convolutions is too small to measure with the aided eye, it is called a closed butt.