Mark Pan
Grounding is the most misunderstood area of Electrical Distribution, bar none. Today's VFD's using efficient and cost effective Insulated Gate Bipolar Transistor's (IGBT's) for the high speed switching, cause damaging High Frequency Ground Currents (HFGC) when conventionally grounded. Damage includes arcing and/or sparking at point of physical earth, premature motor bearing failure (no motor mfg. warranties bearings) and interference with sensitive equipment (which today almost all equipment is sensitive). HFGC can NOT be eliminated, although HFGC can be contained, controlled & redirected. The Zero Ground High Frequency Extraction System (HFES) addresses these damaging issues and reduces HFGC to zero at Physical Earth. Tested at Toshiba and Baldor, endorsed by ABB (the largest VFD manufacturer in the world) and now accepted for use in all USA surface and sub-surface mines by the US Dept. of Labor Mining & Safety health Administration (MSHA), HFES is now the only patented AND proven method to address damaging HFGC.
With VFDs sold in the USA at 15,000 per week and motors sold at 30,000 per week, logic would suggest these type of investments be protected from HFGC. Zero Ground will work with anyone requesting assistance for addressing HFGC issues.