Surge arrester Y20W-420/1046

In power systems, metal oxide surge arresters are used to protect electrical equipments from being damaged by overvoltage. Service conditions as follows: ambient air temperature within the range of -40℃to +40℃; solar radiation not exceeding 1.1KW/m2; altitude not exceeding 2,000m; frequency of the a.c. power supply not less than 48 Hz and not exceeding 62 Hz ; power -frequency voltage applied continuously between the terminals of the arrester not exceeding its continuous operating voltage ; earthquake intensity ≤8; wind speeds ≤35 m/s; a. Excellent protection feature Metal -oxide surge arrester is used to protect electrical equipment in power systems from being damaged by overvoltage .As the core component of an arrester ,metal -oxide resistors have a very good nonlinear volt-ampere characteristic , which limits the overvoltage amplitude and releases the energy of overvoltage intrudes and the current passing through resistor increases rapidly .After that ,the resistor restore a high impedance state ,making the power system work properly ,through which only micor-ampere current passes under the normal working voltage .Due to such a characteristic ,the arrester can be designed to be a structure without gaps ,thus making the arrester have features of small size ,light weight and good protection . b. High discharge current capability The discharge current capability of metal-oxide surge arresters indicates that the arredters can absorb the energy of various lightening overvoltage and switching overvoltage .