Face protection investigation against electric field on live line workers

During the repair processes of power lines with live line maintenance method the the workers are effected to time-varying electromagnetic fields. The extra low frequency (ELF) electric and magnetic fields which are generated surrounding the phase conductors cause both electric current through the human body and eddy current, as well. To protect the workers against electric and magnetic fields, many types of conductive suits are used. These conductive suits do not act as a perfect Faraday cage, because there are “Faraday holes” on them. Simulations by finite element method and laboratory measurements determined that face screening is essential for the proper protection of the worker. Different test arrangements and measurements have been developed to investigate the effectiveness of the conductive suit with and without face screening. The role of face screen has been investigated by two methods. One of these methods is according to IEC 60895 and the other one follows Csikós´ recommendations. Latter is widely used in Hungary to estimate the electric parameters of conductive suits. Results showed that the protective effect has decreased to one tenth without face screening. Face screening reduces the field strength on face and the body current, as well.