Light arrester and their types and role of porcelain insulator

Light arresters are the devices which prevent damage to apparatus from lighting strike. The arresters give less resistance path to the current from a light striking. After providing low resistance to surge in current it comes to the normal position. The arrester has to perform two main function, first it has to give point in the circuit at which an over voltage passes to the ground.  And, second, it prevents flowing of follow- up current to ground.

Lighting arresters are one of the three protective measures adopted to protect the devices and man working on them. The other two measures are earth screening and overhead ground wires.

Earth screening is used at power stations and sub power stations to protect the stations from direct lighting. The use of earth screen provides low resistance path to the cover charge current produced by lightning strike. But it has its limitations, as it does not provide protection against traveling waves in the stations, which may reach the equipments.

Overhead ground wires are used to protect the transmission lines from direct lighting. It also gives damping effect on disturbances traveling along the lines by acting as short circuit. The limits of this type of protective measure are that it can be costly. It can also break and fall across the line conductors, thereby producing short circuit fault.

Types of light arresters –

 Lighting arresters Lightning Arresters Manufacturers in Delhi can also be divided into three classes.  Class one is used to prevent damage to power stations, sub stations and other high voltage areas. The   class one lighting arresters give protection from both surges and lighting striking.

Intermediate class lighting arresters are used to protect transformers, low voltage areas, and sub stations. They also protect from surges and lighting strikes.

Distribution class lighting arresters are for dry type and liquid type transformers. These may also be on the exposed lines having connection with rotating machines.

Secondary class lighting arresters are for protecting homes and businesses from lighting strikes. These lighting arresters offer low level protection to electrical systems and have no protection to solid state technology.    

Electrical insulators are used to protect the flow of current to ground from overhead transmission lines. Various materials are used to make insulators .Porcelain Porcelain insulators manufacturers in Delhi is also  the material that is used to make the overhead insulators .This material is actually aluminum silicate. The porcelain material should be free from any porosity since that reduces its dielectric property.