Guidelines for selecting PPE against arc thermal hazards - the new edition of DGUV-I 203-077: Revision status and experience to date

摘要

Huge energies being released in electric power equipment, there is a high risk for human injury due to electric fault arcs. Persons working at electric power equipment will have to be protected efficiently, particularly, if direct arc exposure is likely. Additionally to technical and organizational control measures, Personal Protective Equipment (PPE) may essentially contribute to prevent injuries. The selection of PPE and the assessment of their efficiency require a risk assessment. The information document and guideline "Thermal hazards from electric fault arc - guide to the selection of personal protective equipment for electrical work" (published in German under DGUV-I 203-077 as well as in English under DGUV-I 203-078) was prepared for giving support to the users when selecting PPE against the thermal hazards of electric fault arcs. An algorithm was developed for selecting PPE for the particular work place and working activities. This user guideline contains detailed explanation and practical examples on how to proceed in risk analysis and determining the arc hazards to be managed, and how to select PPE tested in the box test according to IEC/EN 61482-1-2. According to the developments and experiences from applying the guide during the last years, a revised edition of the document was elaborated by an expert group. The new guideline Is presented, considering mainly the risk assessment and PPE selection. In the paper, the algorithm is described for analyzing the thermal arc risk in case of direct exposure, e.g. during live working or working near to live parts. Since the arc thermal hazards depend on the electric arc energy and the exposure distance, the risk assessment is based on the energy parameters. The PPE has a certain energetic protection level which is related to the test energy level. When having tested according to IEC 61482-1-2 the test level is known from the test arc energy for the arc protection classes: class 1 or class 2. PPE protection levels result from the actual working distance and transmission conditions of the power equipment. The electric arc energy to be expected in the certain work situation in the electric power system and equipment under study when there is an arcing fault has to be determined from the actual system parameters. The clearing time of the protective devises is an essential influence on the arc energy. There is a necessity to co - ordinate the selection of PPE and electric protective devises.