A proposal to evaluate the energy withstand capacity of metal oxide resistors

The evaluation of the energy withstand capacity of metal oxide resistors is the key point to compute the withstand of the complete surge arrester. The resistor energy withstand capacity follows a statistical path. Physical and mathematical modeling for the discharge tunneling phenomena, responsible for the instantaneous resistor failure are presented. A testing method able to determine the reliability of the metal oxide resistor energy withstand capacity is developed. Comments on the physical, mathematical and empirical models are presented. Based on this it is possible to conclude, at least for switching surges impulse, that the energy withstand capacity of a metal oxide resistor is constant.