What is an Insulator?
An insulator is a material or method that restricts the transfer of either heat or electricity. Insulators are used to protect us from the dangerous effects of electricity flowing through conductors. Insulators are materials that have just the opposite effect on the flow of electrons. They do not let electrons flow very easily from one atom to another. Insulators are materials whose atoms have tightly bound electrons. These electrons are not free to roam around and be shared by neighboring atoms. Some common insulator materials are glass, plastic, rubber, air, and wood. Most solid materials are classified as insulators because they offer very large resistance to the flow of electric current. A material used to resist the flow of heat is known as “Thermal insulation”. Thermal insulators work by reducing the rate heat can travel through a space. Basically, they use specific materials which will keep heat-carrying matter from moving. On the other hand, in case of electricity, Electrical insulators detain the electric current to a chosen path. They generally work by using a material with many outer electrons, a condition that will cause low electrical conductivity.
What is Electrical Insulator?
An insulator, also called a ‘dielectric’, is a material that resists the flow of electric charge. In insulating materials valence electrons (outermost electrons in the atoms) are tightly bonded to their atoms. These materials are used in electrical equipment as insulators or insulation. Their function is to support or separate electrical conductors without allowing current through themselves. Some materials such as glass, paper or Teflon are very good electrical insulators and are "good enough" to insulate electrical wiring and cables. Most plastics can serve as practical and safe insulators for low to moderate voltages (hundreds, or even thousands, of volts). Electrical insulation is the absence of electrical conduction. Electronic band theory (a branch of physics) says that a charge will flow if states are available into which electrons can be excited. This allows electrons to gain energy and thereby move through a conductor such as a metal. If no such states are available, the material is an insulator.
What are the uses of Electrical Insulators?
Insulators are commonly used as a flexible coating on electric wire and cable. Since air is an insulator, no other substance is needed to keep power where it should be. High-voltage power lines commonly use just air, since a solid (e.g., plastic) coating would be impractical.
An insulated wire or cable has a voltage rating and a maximum conductor temperature rating.
In microelectronic components such as transistors and integrated circuits (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. Oxidized silicon is quartz, i.e. silicon dioxide.
Some of the Methods of insulating high voltage systems are ceramic or glass wire holders, gas, vacuum, and simply placing the wires with a large separation, using the air as insulation.
