FIELD: electricity.
SUBSTANCE: two-level grounding device comprises grounding grid, which consists of upper and lower levels. Grounding ends of equipment are connected to upper level, and grounding ends of lightning rods and voltage limiters are connected to lower level embedded into soil by depth selected by conditions for prevention of electric breakdown of soil between two levels. Current of lightning flows in lower level of grounding device and is not distributed in upper level as a result of absence of conductive joint between levels. Upper and lower levels of grounding grid may be connected to each other in several points, which are most remote from lightning rods and grounding ends of equipment. In this case weakened current of lightning gets onto upper level of grounding device.
EFFECT: reliable protection of equipment against conductive pulses noise in case of thunderbolts.
2 cl, 1 dwg
