The safety of mining works and even lives of miners depend on the quality of electrical grounding arranged in the mine. Therefore, special requirements are imposed on the arrangement of grounding in the mine.
Inside mines, all types of grounding arrangements must be connected into a single network (except for the spark-safe equipment of telephone communications). The rails of the underground railroad used for transporting goods in the mine are also connected to this network. Even more, all metal parts of machines, equipment, and other machinery located in the mine must be electrically connected to avoid spark generation.
There are main and local grounding arrangements. The main grounding arrangement is a metal bar installed in a water storage or a sump. At least two main grounding arrangements are installed for each mine to provide redundancy in case of a failure of one of them. A single group of main grounding arrangements exists even when the mine has several levels. The grounding system for each level is electrically connected to main grounding arrangements.
Read our article " Grounding of Mining Machinery: Specifics of Regulatory Documents for more details.