What Are Electrical Insulators?
Electrical insulators, or dielectrics, are materials that can withstand the flow of electrical current. In other words, they are nonconducting materials. They are the opposite of electrical conductors which allow electricity to flow through a material. Electrical insulators help coat, protect or support electrical conductors so that the electrical current flows through the conductor. Insulators are protective materials that help prevent electrical shock or sparks.
Electrical insulators are made up of substances with electrons, or energy particles that are compressed together by chemical process. It is almost impossible to get electrical voltage to pass through these materials. Some insulators are considered to have higher thresholds for electrical voltage than others do, and are aptly called high voltage insulators.
Glass was used as the earliest electrical insulators. Glass, along with other non-metallic materials such as porcelain, mica, and ceramic can withstand the highest volts of electrical current. Since the 1800s, glass helped to protect exposed telegraph wiring. Rubber was invented in the mid-1800s, and as an electrical insulator, it was initially applied to portions of the glass insulators used to protect telegraph wiring. Rubber, along with plastics, has a lower voltage threshold than glass and porcelain, because of their loose electron composition.
With the advance of telecommunications, Teflon® and silicon dioxide came to be used as electrical insulators to protect against exposed wiring. These materials help protect power lines, and internal wiring within transformers and generators.
There are also composite insulators that derive from a mixture of several materials. Composite electrical insulators are suitable for a variety of electrical engineering purposes ranging from automobiles to appliances. These composite insulators tend to lack the strength that glass and porcelain has to withstand high electrical voltage and can wear out faster. They are ideal for a large-scale manufacturing applications because of their low costs and versatility. Porcelain insulators can break easily and can be bulky. Rubber and other composite insulators, also call non-ceramic insulators, are therefore more widely used for engineering purpose.
Written by S. Roberts
