Insulation Coordination of Forced Drainage in Electric Railway

직류방식 전기철도에서 강제배류기의 절연협조

The forced drainage set up to decrease the cathodic protection in each kind of steel conduit laid under the ground is so proscribed to be maintained less than 60V in its output voltage that insulation coordination is easy to be left out of account, on the basis of 60V of working voltage. When railway or subway break down during the service of a subway, 1,500 voltage approximating to line voltage flows through the load terminal of the drainage (rail and underground conduit) though momentary in the worst case. And so, an accident followed by dielectric breakdown, fire and damage by a fire is expected. Therefore, I suggest that insulation coordination should be considered against such a thing on designing, producing and setting up forced drainage.