In general the insulating materials used in cables should have the following properties.
Electrical properties of cable insulation materials.
During the historical development of cables numerous types of insulation have been employed.
Effect of water and tropical tests.
During recent years there has been some consolidation in the types of insulation used.
Cable insulation is used to provide electrical separation between conductors of a cable.
Polymeric materials are employed as the insulation but the nature of the polymer may vary with the voltage class.
Can bus data cable.
Electrical insulation materials are employed over the metallic conductors of underground cables at all voltage ratings.
However the chlorine in pvc a halogen causes the production of thick toxic black smoke when burnt and can be a health hazard in areas where low smoke and toxicity are required e g.
High insulation resistance to avoid leakage current.
Water directly lowers electrical properties such as electrical resistance and dielectric strength.
Confined areas such as tunnels.
Thermoplastic compounds are materials that go soft when heated and harden when cooled.
It is cheap durable and widely available.
Learn about the physical properties of different insulation and jacket materials.
The electrical behavior of insulating materials is influenced by temperature time moisture and other contaminants geometric relationships mechanical stress and electrodes and frequency and magnitude of applied voltage.
Since paper insulation was used first in the power industry and was later replaced in low and medium voltage applications any comparison of properties usually employs the paper fluid system as the standard.
Polypropylene has been regarded as a potential recyclable insulation material for hvdc cable which is beneficial to improve the working temperature and transmission capacity of hvdc cables.
Electrical properties of polyolefins poly olefin structure and dielectric behavior.
Temperature dependent electrical properties of thermoplastic polypropylene nanocomposites for hvdc cable insulation abstract.
The suitability of insulating materials for such conditions can be decided by a long experience.
Cables laid in the soil can deteriorate by the action of chemicals in soils.
Pvc polyvinyl chloride is the most commonly used thermoplastic insulator for cables.