Distribution Automation Handbook

ABB

Distribution Automation Handbook

Publicado: 11 de outubro de 2022 · Categoria: Cadernos técnicos

Deste documento

Distribution Automation Handbook Section 8.1 Electrical Safety Distribution Automation Handbook (prototype) 1MRS757284 Power System Protection, 8.1 Electrical Safety 2 Contents 8.1 Electrical Safety ................................................................................................................................. 3 8.1.1 Introduction .............................................................................................................................. 3 8.1.2 Earth-fault voltage and earthing resistance ............................................................................. 3 8.1.3 Effects of hazard voltage to the human body ............................................................................ 6 8.1.4 Permissible touch and earth-fault voltages vs. relay settings .................................................. 8 Distribution Automation Handbook (prototype) 1MRS757284 Power System Protection, 8.1 Electrical Safety 3 8.1 Electrical Safety 8.1.1 Introduction Metallic parts of electrical equipment that can be exposed to voltage due to insulation failures are usually connected to earth potential, that is, earthed. This is done to protect the equipment against excessive overvoltages and to limit the damage to material and property and especially the hazard to the public. Mainly due to the last reason, safety regulations have been given by the authorities on how these hazard voltages must be limited. In the regulations, typically both the magnitude...