Protective Black Tape

Electrical tape (or insulating tape) is a type of pressure-sensitive tape used to insulate electrical wires and other materials that conduct electricity. It can be made of many plastics, but vinyl is most popular, as it stretches well and gives an effective and long lasting insulation. Electrical tape for class H insulation is made of fiberglass cloth.

A wide variety of electrical tapes is available; some for highly specialized purposes. “The primary tapes used in electrical applications are vinyl, rubber, mastic, and varnished cambric.”^[1] Electricians generally use only black tape for insulation purposes. The other colors are used to indicate the voltage level and phase of the wire. (In fact, the colored tape is referred to as “phasing tape.”) This is done on large wire which is available only in black insulation. When wires are phased, a ring of tape is placed on each end near the termination so that the purpose of the wire is obvious.