Properties of insulating material and types of insulators

Insulators are kept in electrical systems to prevent the flow of current to earth from its supporting points. The insulator material has very high resistance to the flow of current. In overhead lines are supported by the poles, which are grounded, the insulator is used to prevent the flow of current from the transmission lines to the ground through the poles supporting the transmission lines.

Properties any insulating material must have -

 The insulating material must be strong enough to support the weight and tension of the conductors. Since, insulators are also used in high voltage systems; it must have high dielectric strength to withstand the voltage stress of high voltage systems. Another important quality of the insulator material is that it must give high resistance to the flow of current.

The insulating material should be free from any impurities and it must not have any opening through which any moisture or gases can enter through. At the same time, the electrical or physical properties of the insulating material must not change with the passing temperature

Types of insulators –

Porcelain insulators are the commonly used insulators for over head lines. Porcelain is basically aluminum silicate...This aluminum silicate is mixed with quartz, plastic, feldspar to get the final product. The surface Porcelain insulators manufacturers in Delhi of the porcelain material is so glazed that water cannot stand on it and also it is free from any porous or impurities.

Glass insulators are also being used in overhead transmission lines. The glass insulators have number of advantages over porcelain insulators. The glass insulators have high resistance to flow of current and their thermal co efficiency is low. The major benefit of using glass insulators is that they have longer life and are not affected by aging. However, they are vulnerable to heating and collecting dust and moisture.

Polymer insulator comes in two parts. One part is known as core part made and another is shed part that covers the core part. The core part is rod part and shed part is weather shed part. The shed part protects the rod part from weather conditions. The two extreme sides of the rod part have Lightning Arresters Manufacturers in Delhi galvanized cast steel ends. Polymer insulator is very light and very flexible to minimize the breaking chances. The light weight and smaller size has kept its installations cost low. However, the chances of moisture entering the insulator are also high due to any gap between rod and sheds.

Installation methods of lighting arresters

The main function of the voltage arresters is to save the objects or building from lighting. This is done by clearing way for the current to go to the ground as fast as possible .This arrangement is done by using voltage and lighting arresters to the grounded robs .The voltage surge is generated by the lighting near home or it can also be generated by the cloud to cloud lighting near or over home.

The first step, which everybody should do, is to create excellent system for grounding of all household electrical system. Sometimes the single metallic rod may not be adequate. The heavy voltage surge cannot be handled by single metallic rod.  By connecting more than one rod to the ground, one can easily take the voltage surge to the ground. All these rods must have solid copper wires wielded on them. This solid copper wire is taken from the grounding bar inside the electrical panel and ends at the last rod connected on the ground. These grounding rods are at least ten feet apart from each other. These rods must be put into the soil which is very good conductor of the electricity. Moisture laden soil is generally good conductor of the soil. The soil with sand, rocks and gravels are not good conductor of soil. They offer resistance. The resistance range should be between 10 – 30 ohms. The lower resistance readings are always better.

Installing lighting arrester Lightning Arresters Manufacturers in Delhi inside the electric c service panels is the second method of grounding voltage surge. The job of the arrester is effective only when there are grounding robs. These light arresters can very effective in cutting large voltage surges which travel in power lines. The arrester cannot do the job, if there are no enough rods in the ground or grounding wires. The arresters must be able to send the voltage surge into ground fast. Every circuit makers installs one into their panels. The installation of arresters can also be done by the householder who knows how to install in high voltage panel.  But preferable an experienced electrician should be called for the service.

The voltage surge Porcelain insulators manufacturers in Delhi can also come through phone lines, so there are devices to protect the phones. The surge can also enter the computer system through telephone lines. So this line should also be protected. The telephone grounding lines have to be tied to the upgraded grounding electrical system.

Applications & Constructions of Lighting Arresters and Power Transmission Insulators

Electrical power systems make use of lighting arresters for the purpose of protecting the insulation and conductors of the electrical systems from the damages caused due to lightning. Fabricated by using cutting-edge machinery, the lightning arresters have a ground terminal and a high-voltage terminal and are used in telecommunications systems. The lightning arresters are used in telegraphy and telephony where the lightning arresters are placed at the point where the telephonic cables enter a structure. Use of lighting arrester prevent the damage for electronic instruments within a close proximity and also ensure safety of individuals in close proximity.

Surge insulators or surge protectors are known as smaller versions of lightning arrestor are connected between each electrical conductor in the earth, electrical conductor and communication systems. Signal current and normal power flow to the ground is prevented by using the surge protector and provide an alternate path by the connected equipment over which high voltage lightning current flows.  The use of surge protector limits the rise in the voltage when the electrical power line or telephonic line is stuck by lightning.

Thousands of kilovolts of power are generated in the power line or telephonic system, if the lightning arrester fails or are absent. Transformers, insulators and conductors can be damaged through the exposure of the thousands of kilovolt of current due to the lightning. For ensuring optimum protection of the lightning arresters, it is often recommend make use of lightning arresters that are manufactured by Lightning Arresters Manufacturers in Delhi.

Death apart from damaging of the power system/equipment can be caused due to lightning. It is necessary to make use of right kind of the lightning arresters for protection the power system and telecommunication systems from damage caused by the lightning.  

Power Transmission Insulators

In most power transmission applications, the insulators used are precisely fabricated from premium quality of composite polymer, glass or porcelains. Clay, quartz or alumina and feldspar are used for manufacturing of the porcelain insulators by some of the best Porcelain Insulators Manufacturers in Delhi.  

In power transmission application where high mechanical strength is required, the alumina rich porcelain insulators are used. 4–10 kV/mm is the dielectric strength of the porcelain from that the most of the porcelain insulators are used in various power transmission applications. Although glass has much greater dielectric strength but glass insulators are associated with attracting condensation and thick shapes. 

Basic physics of insulators and conductors and types of insulators

Conductors are the materials which permit the flow of current from entire body of the material. The charge can pass from the conductor to the other body connected with the conductor. If any charge is given to the body of the conductor, that charge is transferred to the entire body of the conductor. This distribution of the charge is result of the movement of the electrons.  The charging of the other body with conductor also depends on whether that body is made up of conducting material.

Contrary to this, the insulators are the objects that do not allow the free movement of the electrons through its body. They resist the flow of current or charge through them. In other words, if charge is given to the insulator, the charge will remain at the point of the contact. There is not free flow of electrons in the body of the insulator.

But the role of these insulators is very important in transmission of electricity from generation point to distribution and consumption points.  The conducting materials are always put on the insulator materials. This arrangement is very essential in preventing the spread of charge or electricity from conducting material to surrounding areas. The pin type insulators are secured to the cross arm of the pole. The grove on the top end of the insulator holds the conducting material. The pin type insulators are used in distribution and transmission of electricity current at the voltages up to 33 kV. Beyond this voltage level, the uses of pin type insulator become uneconomical.

Suspension type insulator Porcelain insulators manufacturers in Delhi is used for the transmission of current beyond 33 kV. This insulator is basically consists series of porcelain discs. These discs are conducted by metal links. The conducting material is connected at the bottom end of the string of these discs and upper end of the string is connected with the cross arm of the pole. Each disc is designed for low voltage. And for  total higher voltage, the number of discs can be increased .For example  , if the discs is designed for 11 kv voltage , then for 66 kv voltage , the 6 discs are required .

Suspension insulators have many advantages compare to pin type insulator. They are cheaper for higher voltages. One disc can be replaced and whole string of discs will not become useless. And by increasing the number of discs in the series, the insulator can be made to meet the increased demand of transmission.

Strain insulators Air Break Isolating Switches Manufacturers in Delhi are used to relieve the tension of the transmission line when it passed the sharp curve or is connected at the final end place. The strain insulators are used as vertical suspension insulators for higher voltages .Shackles insulators are used for low voltage distribution lines. They are secured with the poles and can be used in vertical or horizontal positions. Shackles insulators are used as strain insulators at low voltages.