Application of insulating materials
Cables and transmission lines:
Insulating material is generally used as a protective coating on electrical conductor and cables. Cable cores which touch each other should be separated and insulated by means of insulation coating on each core, e.g. polyethylene, cross linked polyethylene-XLPE, polyvinyl chloride-PVC, Teflon, silicone etc. Hanging disk insulators (bushings) are used in high voltage transmission bare cables where they are supported by electrical poles. Bushings are made from glass, porcelain, or composite polymer materials.
All electronic appliances and instruments widely contain PCB (printed circuit boards) having different electronics components on them. PCBs are manufactured of epoxy plastic and fiberglass. All electronics components are fixed on the insulated PCB board. In SCR (semiconductor rectifiers), transistors and integrated circuits, the silicon material is used as a conductive material and can be converted into insulators using a heat and oxygen process.
Transformer oil is widely used as an insulator to prevent arcing in transformers, stabilizers, circuit breakers, etc. The insulating oil can withstand insulating properties up to a specified electrical breakdown voltage. Vacuum, gas (sulfur hexafluoride), and ceramic or glass wire are other methods of insulation in high voltage systems. Small transformers, power generators, and electrical motors contain insulation on the wire coils by the means of polymer varnish. Fiberglass insulating tape is also used as a winding coil separator.
Domestic portable appliances:
All hand held electrical appliances are insulated to prevent their user from electrical shock hazard.
- Class 1 insulation contains only basic insulation on the wire and the metal body is earthed at the main grounding system. The third pin on the power plug shall be for the grounding connection.
- Class 2 insulation denotes a device with "double insulation." All internal electrical components shall be totally enclosed within an insulated body which will prevent any shorting with conductive parts.
Electrical cable insulating tape:
PVC tapes are widely used to insulate electrical wires and other live conductive parts. It is made of vinyl as it stretches well and provides effective and long-lasting insulation. Electrical tape for class H insulation is made of fiberglass cloth.
Personal protective equipment:
PPE protects humans from the hazards of shock with electrical circuits. PPE such as insulating head protection, eye and face protection, and insulating gloves are necessary for protection against all common electrical hazards. Insulated tools and protective shields are must for an electrician's safe working. Dielectric shoes (non-metallic safety footwear) or electrical hazard footwear is made with non-conductive, electrical shock-resistant soles and heels.
Electrical rubber mats:
Insulating mats for electrical purposes have a wide application in various substations, power plants, etc. The mats are used for floor covering below control panels to provide for the safety of workman due to any possible leakage of current.