Comparison of conductive clothing´s effectiveness

Power lines are surrounded by electric and magnetic fields which decrease as a function of the distance. The electric field depends on the voltage level and the magnetic field depends on the current which flows through the conductors. During live-line maintenance the workers are exposed to both high electric and magnetic fields near the conductors. The electric field can be shielded effectively with conductive clothing. This clothing act as a Faraday cage, but the shielding efficiency depends on the material, the configuration [1-4] and the size of the holes as well (some “Faraday holes” are enabled as a function of the frequency). Calculations, simulations and models using finite element method showed that the miss of the face screen decreases the protective effectiveness significantly. This phenomenon was confirmed by different types of measurements as well. The high fields endanger the health of workers, because the exact effects and limits are unknown yet. Most of conductive clothing is manufactured without any face screening, which decrease the shielding efficiency significantly. BME has developed additional face screen which can be applied to conductive clothing originally made without it. Experimental feedbacks from the industry confirm that live-line works became more comfortable and safer with the use of the modified clothing.