PURPOSE: To easily and surely measure voltage of a bus line so that apprehension of damage by a lightening stroke can be prevented, to save set up space while bus line voltage can be measured and damage by the lightning stroke can be prevented corresponding to a stain condition.
CONSTITUTION: A bus line voltage detecting device is provided with lightning protection insulators 8a connected through connection wires 9, 10 between a power line and the ground to receive a resistance element 29 with the voltage- current characteristic non-linear and a bus line voltage detecting mechanism provided in a ground line 10. This bus line voltage detecting mechanism comprises a current detecting part 40 and a measuring part 41 for measuring a current flowing in this current detecting part 40 to convert this current value into a voltage value. The bus line voltage detecting mechanism comprises a voltage detecting part and a measuring part for measuring voltage by this voltage detecting part. Further, a voltage measuring dielectric element is provided in parallel to the resistance element 29 in the lightning protection insulator 8a. In addition, the lightning protection insulator 8a constitutes a lightning protection insulator train 8 of connecting a plurality.
TAKAGI TOSHIYUKI
YOSHIDA SHINJI
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