EQUIPOTENTIAL EARTHING DEVICE

摘要

PURPOSE: An equipotential grounding apparatus is provided to steadily operate facilities by forming an equipotential through the removal of an electric potential difference. CONSTITUTION: A load system(30) is connected to a phase AC power L1(1), a phase AC power L(2), and a phase AC power L3(3). A protection ground(24) is connected to the load system. A system ground(12) and a protection ground are formed of an independence ground mode. An electric potential difference is generated between the system ground and the protection ground. An equipotential part(51) is serially connected between the neutral line(4) of a transformer and the protection ground of the load system. The system ground and the protection ground are connected to the neutral line. The equipotential part eliminates an electric potential difference according to the electric potential difference of a critical value due to a lightning stroke surge or all kinds of surges. A potentiometer(44) measures the electric potential difference between the protection ground and the system ground.