In the wonderful world of electricity, materials are classified as either electrical insulators or conductors. This classification is based on the material’s ability to conduct electricity.
What Are Electrical Insulators?
Conductors permit electrons to flow freely from one particle to another while insulators are materials that impede the free flow of electrons. This article will explore the properties that make a material an insulator and the various electrical insulators used today
Electrical insulators are useful in protecting us from the dangers of electricity flowing through a conductor. If a voltage is high enough, electrical current can flow through materials that are not conductors. This can happen in the body when a person receives an electric shock.
Examples of Electrical Insulators
There are several materials that can be used as electrical insulators. They are as follows:
Rubber: Rubber has been used as an electrical insulator since 1870. It makes a good insulator because its molecules are tightly bound and it requires a lot of energy to break them apart. The bound electrons cannot be shared by neighboring atoms so the electrons slow down and eventually don’t move at all. The rubber used as an insulator is either its natural or synthetic form.
Glass: Glass was once often used as an electrical insulator. Like a rubber, it has excellent insulator properties as all its electrons are tightly bound around the atoms leaving no free electrons to conduct electricity.
Plastic: Plastics also contain tightly bound electrons that are difficult to move, making them good insulators. They are often used in applications including wrapping wires and electrical tape. Interestingly enough, the properties that make plastic a good insulator are also good thermal insulators.
Porcelain: Porcelain can make a high-quality insulator which can be used in applications including holding an electrified wire near to a fence post without losing energy through the post. It has higher insulating powers than plastic, long-lasting and resistant to sun damage. However, porcelain is also generally more expensive than most other insulators.
Clay: Clay can be used in many applications, similar to that of porcelain. It is less expensive than porcelain, but it is also more susceptible to damage like cracking and chipping.
Wood: Like glass, wood was often used as a conductor many years ago. It was not uncommon to see wood being used as a backing plate for bakelite switches or ceiling roses. However, it is rarely used today due to fact that the material can easily absorb water, which degrades its insulating properties and can result in a mishap.
Paper: Paper is often used as an insulator due to the fact that one of its main constituents, celluloid, has excellent insulation properties. Cable paper is used for moderate voltage cables while high voltage power cable paper is used for more demanding applications. Capacitor tissue is used in capacitors and transformer board is used in oil filled transformers where a solid insulating structure is needed.
Oil: Oil is used as an insulator in a transformer. It is kept in the core where the winding is stored in a tank of oil. The oil prevents the outer metallic casing from being electrocuted. It is also used in breakers, and switchgear where it serves to quench arc formation.
Wax: Paraffin wax is an excellent electrical conductor, second only to certain plastics. It contains a non-polar, organic covalent compound which means it has no free electrons that can carry a charge. It can be used in small, battery-operated applications and was also used in certain capacitors, transformers and receivers many years ago.
It is a good idea to learn about different types of electrical insulators, whether you are a professional, or just working on a science project. It will give you a broad knowledge of the science behind electrical conduction, aid you to complete projects around the house and also help to keep you safe in potentially dangerous situations.