Editing Insulator (electricity) (section)

==Uses==
A flexible coating of an insulator is often applied to electric wire and cable; this assembly is called ''insulated wire''. Wires sometimes don't use an insulating coating, just air, when a solid (e.g. plastic) coating may be impractical. Wires that touch each other produce cross connections, [[short circuit]]s, and fire hazards. In [[coaxial cable]] the center conductor must be supported precisely in the middle of the hollow shield to prevent electro-magnetic wave reflections. Wires that expose high voltages can cause human shock and [[electric shock|electrocution]] hazards.

Most insulated wire and cable products have maximum ratings for voltage and conductor temperature. The product may not have an [[ampacity]] (current-carrying capacity) rating, since this is dependent on the surrounding environment (e.g. ambient temperature).

In electronic systems, [[printed circuit board]]s are made from epoxy plastic and fibreglass. The nonconductive boards support layers of copper foil conductors. In electronic devices, the tiny and delicate active components are embedded within nonconductive [[epoxy]] or [[Phenolic resin|phenolic]] plastics, or within baked glass or ceramic coatings.

In [[semiconductor device|microelectronic components]] such as [[transistor]]s and [[integrated circuit|ICs]], the silicon material is normally a conductor because of doping, but it can easily be selectively transformed into a good insulator by the application of heat and oxygen. Oxidised silicon is [[quartz]], i.e. [[silicon dioxide]], the primary component of glass.

In [[high voltage]] systems containing [[transformer]]s and [[capacitors]], liquid insulator oil is the typical method used for preventing arcs. The oil replaces air in spaces that must support significant voltage without [[electrical breakdown]]. Other high voltage system insulation materials include ceramic or glass wire holders, gas, vacuum, and simply placing wires far enough apart to use air as insulation.