Thyrite Lightning Arrester and its Function

A thyrite lightning arrester is a type of surge protection device used in electrical systems to protect against voltage surges caused by lightning strikes or other transient events. It is designed to divert the excessive current from the lightning strike to the ground, preventing damage to sensitive equipment and electrical systems.

Resistance in a Thyrite Lightning Arrester

The resistance in a thyrite lightning arrester plays a crucial role in its operation. It determines the ability of the arrester to conduct current and dissipate the energy from the lightning strike.

High Resistance at Low Current

At low current levels, such as during normal operating conditions, the resistance of the thyrite lightning arrester is high. This means that it does not conduct much current and remains in a non-conductive state. The high resistance prevents the arrester from interfering with the normal operation of the electrical system.

Low Resistance at High Current

During a lightning strike or a transient event, the voltage across the thyrite lightning arrester increases significantly. As the voltage increases, the resistance of the arrester decreases. This is due to the nature of the thyrite material, which exhibits a nonlinear resistance characteristic.

Nonlinear Resistance Curve

The resistance of a thyrite lightning arrester does not vary linearly with the applied voltage. Instead, it follows a nonlinear resistance curve. This means that as the voltage increases, the resistance decreases rapidly, allowing the arrester to conduct a large amount of current.

Protecting the Electrical System

By having a low resistance at high current levels, the thyrite lightning arrester effectively diverts the excessive current from the lightning strike to the ground. This prevents the current from flowing into the electrical system and causing damage to sensitive equipment.

Conclusion

In summary, the resistance in a thyrite lightning arrester is high at low current levels and low at high current levels. This characteristic allows the arrester to protect electrical systems from voltage surges caused by lightning strikes or transient events. The nonlinear resistance curve of the thyrite material ensures that the arrester conducts a large amount of current during a lightning strike, effectively diverting the energy to the ground and protecting the electrical system.