Specific features of electrical equipment grounding on a mine site to comply with the requirements for effective protection of personnel against electric-shock hazards

Abstract

The paper provides evidence that the existing standardized design concept of power supply systems for the mine sites inherently involves existence of an electrical shock hazard to humans when touching the phase of the network. This hazard is caused by the active and capacitive conductance of the insulation due to grounding of the central cores of the flexible shielded mining cables. The functional inefficiency of the ground fault protection used in the mining industry has been proved, including the cases of mine electric networks with high power consumption. An alternative concept was justified to design the power supply system for a mine section electric network, which excludes grounding of the central cores of the flexible cables. This approach implements the principle of selective shutoff protection of the electrical consumers in the mine section using local means to control the condition of insulation in the power connections.