Currents in power line wood poles

Over the last few years some rather severe problems have arisen for poles used to support overhead power lines. A wooden power line pole is assumed to be a good electric insulator because of the basic properties of wood with its porous structure and cellulose compounds forming the major part of the cell walls. A fault during which an insulator is broken or a phase conductor has loosened, normally poses no danger. In rare cases a fire has started, but this has not been seen as a sufficiently dangerous situation to change maintenance practice. However, it has been noticed that under certain circumstances such poles can get conductive enough to result in hazardous or even lethal current for power line maintenance workers climbing the pole.<p>Validerad; 2011; 20110613 (ronsar)