Electrical tape is a type of pressure-sensitive tape used to insulate

Electrical insulation

thumb|250px|[[Coaxial Cable]] with dielectric insulator supporting a central coreThis article refers to electrical insulation. For insulation of heat, see Thermal insulation...

 electrical wires and other material that conduct electricity

Electricity

Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

. It can be made of many plastic

Plastic

A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...

s, but vinyl

Vinyl

A vinyl compound is any organic compound that contains a vinyl group ,which are derivatives of ethene, CH2=CH2, with one hydrogen atom replaced with some other group...

 is most popular, as it stretches well and gives an effective and long lasting insulation. Electrical tape for class H

Insulation system

The insulation system for wires used in generators, electric motors, transformers, and other wire-wound electrical components is divided into different classes by temperature and temperature rise. The insulation system is sometimes referred to as insulation class...

 insulation is made of fiberglass cloth.

Varieties

A wide variety of electrical tapes is available; some for highly specialized purposes. Electrician

Electrician

An electrician is a tradesman specializing in electrical wiring of buildings, stationary machines and related equipment. Electricians may be employed in the installation of new electrical components or the maintenance and repair of existing electrical infrastructure. Electricians may also...

s generally use only black tape for insulation purposes. The other colours are used to indicate the voltage

Voltage

Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...

 level and phase

Polyphase system

A polyphase system is a means of distributing alternating current electrical power. Polyphase systems have three or more energized electrical conductors carrying alternating currents with a definite time offset between the voltage waves in each conductor. Polyphase systems are particularly useful...

 of the wire. (In fact, the coloured 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. The following table describes this usage.

Tape colour	Usage (US)	Usage (UK – old)	Usage (International – new)
Black	Insulation Low voltage, phase A	Insulation Low voltage, neutral	Low voltage, phase B
Red	Low voltage, phase B	Low voltage, phase A	Sheath, 415 V 3 phase
Blue	Low voltage, phase C	Low voltage, phase C	Low voltage, neutral Sheath, 230 V
Brown	High voltage, phase A		Low voltage, phase A
Orange	High voltage, phase B		Sheath, garden tools
Yellow	High voltage, phase C	Low voltage, phase B	Sheath, 110 V site wiring
Green	Earth ground	Earth
Green with yellow stripe	Isolated ground		Earth
Grey	Low voltage, neutral High voltage, neutral		Low voltage, phase C
White	Low voltage, neutral High voltage, neutral

Tape that is approved for electrical applications will carry an approval label from an agency such as Underwriters Laboratories

Underwriters Laboratories

Underwriters Laboratories Inc. is an independent product safety certification organization. Established in 1894, the company has its headquarters in Northbrook, Illinois. UL develops standards and test procedures for products, materials, components, assemblies, tools and equipment, chiefly dealing...

.

Non-electrical applications

As it is easily torn by hand, can be written on, and generally removes from smooth surfaces cleanly, it is useful for a number of other applications such as labelling (including colour coding) and temporarily attaching objects to one another. It can be torn by hand or cut with tools.

Electrical tape is used in non-electrical applications for identification, or improvised and temporary repairs. Furthermore, light colored electrical tapes are used as rigging tape on sailboats. Other uses include makeshift grips on tool items such as hammers, or as a replacement for the more common duct tape

Duct tape

Duct tape, or duck tape, is cloth- or scrim-backed pressure sensitive tape often sealed with polyethylene. It is very similar to gaffer tape but differs in that gaffer tape was designed to be cleanly removed, while duct tape was not. It has a standard width of and is generally silver or black...

.

History

The original electrical insulating tape was made of cloth tape impregnated with Chatterton's compound

Chatterton's compound

Chatterton’s compound was an adhesive waterproof insulating compound that was used in early submarine telegraph cables.Its constitution is as follows:*3 parts gutta-percha*1 part rosin*1 part Stockholm tar...

, an adhesive material manufactured using Gutta-percha

Gutta-percha

Gutta-percha is a genus of tropical trees native to Southeast Asia and northern Australasia, from Taiwan south to the Malay Peninsula and east to the Solomon Islands. The same term is used to refer to an inelastic natural latex produced from the sap of these trees, particularly from the species...

. This type of tape was often used to insulate soldered

Soldering

Soldering is a process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, the filler metal having a lower melting point than the workpiece...

 splices on knob and tube wiring

Knob and tube wiring

Knob and tube wiring was an early standardized method of electrical wiring in buildings, in common use in North America from about 1880 to the 1930s...

.

In the early 1940s, vinyl plastic emerged as a versatile material for a wide range of applications, from shower curtains to cable insulation. A major ingredient in vinyl film was tricresyl phosphate

Tricresyl phosphate

Tricresyl phosphate, abbreviated TCP, is an organophosphate compound that is used as a plasticizer and diverse other applications. It is a colourless, viscous liquid, although commercial samples are typically yellow...

 (TCP), which was used as a plasticizer. Unfortunately, TCP tended to migrate, giving the surface of the vinyl film an oily quality and degrading every tape adhesive known. Research chemists and engineers at 3M

3M

3M Company , formerly known as the Minnesota Mining and Manufacturing Company, is an American multinational conglomerate corporation based in Maplewood, Minnesota, United States....

 set out to create a dependable, pressure-sensitive tape made of vinyl film that would have the required electrical, physical and chemical properties.

Experiments were conducted combining new plasticizers with the white, flour-like vinyl resin. Finally, in January 1946, inventors Snell, Oace, and Eastwold of 3M applied for a patent for a vinyl electrical tape with a plasticizer system and non-sulfur-based rubber adhesive that were compatible. The first commercially available version of the tape was sold for use as a wire-harness wrapping. Interestingly, this original black tape wasn't black at all. Tapes formulated for high-temperature were yellow, and later versions were white. White tape, because of its instability in ultraviolet light, was eventually replaced with black tape, although colored vinyl tapes are still used as identification and marking tapes. Black became the standard industry color for vinyl standard tape, primarily because of its ultraviolet resistance. Thicknesses originally were 4 mil (100 µm), 8 mil (200 µm) and 12 mil (300 µm). These were standardized to 7 mil (180 µm) and 10 mil (250 µm) in 1948.

External links

• http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTtMxMy58&aEVuQEcuZgVs6EVs6E666666-- Electrical Taping Skills: A Lost Art?
• http://www.eham.net/articles/5067 Electrical Tape Tips by KØFF
• ASTM D1000 - Test methods for electrical tapes