What is The Lightning Arrester?
Lightning arresters are devices that help prevent damage to apparatus due to high voltages. The arrester provides a low-impedance path to ground for the current from a lightning strike or transient voltage and then restores to normal operating conditions.
How Lightning Arrester Works?
A lightning arrester may be compared to a relief valve on a boiler or hot water heater. It will release high pressure until a normal operating condition is reached. When the pressure is returned to normal, the safety valve is ready for the next operation.
When a high voltage (greater than the normal line voltage) exists on the line, the arrester immediately furnishes a path to ground and thus limits and drains off the excess voltage. The arrester must provide this relief and then prevent any further flow of current to ground.
Function Of Lighting Arrester
1) It must provide a point in the circuit at which an over-voltage pulse can pass to ground.
2) To prevent any follow-up current from flowing to ground.
3) It limits the voltage produced by lightning.
4) It protects the equipment connected in parallel with it
The transformer is the heart of modern power system. so it is mandatory to protect the transformer from any kind of disturbances.
High voltage occurs due to lightning create insulation failure in transformers. This is the reason why lightning arresters are placed close to the transformer.