An experimental study on the response of concrete pole to current impulses

Concrete poles with steel reenforcing are mostly used as KEPCO's overhead distribution line poles. The reenforcing should be of rod or wire and the thickness of concrete cover can be thin as 9 mm. The exposed reenforcing on the pole top which should be sealed with mortar or concrete by rule, does not touch the metallic supporter for overhead ground wire normally, however, as the bottom treatment is not prescribed, exposed reenforcing will easily constitute electrical contact with earth when erected for normal use. Under normal operations, concrete pole will do nothing electrically as seen above, and concrete poles are usually treated as insulated things even when insulation coordination is studied. In this study, current flowing through pole itself, while comparatively small impulsive current flow through the ground lead by injecting current impulses to overhead ground wire, were found experimentally.