Mining system reduces ground currents

Zero Ground announces its High Frequency Extraction System (HFES), which reduces high-frequency ground currents. The HFES solution was engineered for use wherever ac induction motors operate in conjunction with variable frequency drive (VFD) applications, and for applications where large switching power supplies are used.
By Control Engineering Staff June 1, 2008

Zero Ground announces its High Frequency Extraction System (HFES), which reduces high-frequency ground currents. The HFES solution was engineered for use wherever ac induction motors operate in conjunction with variable frequency drive (VFD) applications, and for applications where large switching power supplies are used. It has been formally approved by the U.S. Department of Labor, Mining and Safety Health Administration (MSHA), for use in underground and surface mines in the U.S.; it has also been approved by the Bureau of Mine Safety, Commonwealth of Pennsylvania. A completely passive system, it utilizes no filters or brushes, and the design provides benefits exceeding 500 ft. lengths. HFES has been issued a ā€œPā€ number to be used in conjunction with the MSHA approval number. www.zero-ground.com Zero Ground