SECTION OF ELECTRIC NETWORK Russian patent published in 1998 - IPC

FIELD: electrical engineering, specifically, neutral earthing devices of industrial electric installations of production facilities. SUBSTANCE: extended grounding rod with discrete or continuous leak of current in which capacity construction mainframe of production building or facility connected in parallel to fourth conductor of cable of electric network by zero protection conductor is used as additional zero protection conductor. Cable is laid in zone limited by two circular cylinders which axes coincide with axis of hypothetical equivalent conductor substituting construction mainframe of production building or facility - extended grounding rod. Optimal distance between cable and axis of equivalent conductor is found from condition of minimum of potential-forming current that is illustrated by drawings. EFFECT: diminished potential of neutrally earthed electric installation to safe values independent of speed of response with minimal material and labor expenditures. 2 dwg