PURPOSE: To easily diagnose the deterioration of a zinc oxide type element by attaching an oxygen concentration meter for measuring oxygen concentration in an arrester to the arrester having the element containing zinc oxide as a main ingredient.
CONSTITUTION: Oxide is added to a zinc oxide type element disposed in an arrester 1 and containing as a main ingredient ZnO, and the element is obtained by mixing, molding and baking the oxides. As the oxides, Bi2O3, Sb2O3, CO2O3, MnO2, Cr2O3, SiO2, etc., are employed. In the arrester 1, a voltage is always applied to the element. If the deterioration of the element to increase its leakage current is proceeded, oxygen is discharged from the components of the oxides. Oxygen concentration in the arrester 1 is measured by a zirconia type oxygen concentration meter 10, and the state of the deterioration of the element can be known by the value.
KOBAYASHI MASAHIRO
MINAGAWA TADAO
UJITA KATSU
