DIRECT-CURRENT SYSTEM GROUND DETECTOR Russian patent published in 1995 - IPC

FIELD: instrumentation engineering. SUBSTANCE: offered device, its analogs and prototype are noted for their ability to measure during detected time instants equivalent insulation resistance (R_и.э) of poles of mains under check to ground; each time before taking measurements electric bridge two of whose arms are essentially R_и.э components of insulation resistance and two other ones are sides of controlled resistive voltage divider, is balanced out; for each measurement, d.c. voltage source is connected across two diagonally opposite terminals of bridge with indicating resistor by means of switching component. Each time after measurements calculations are made using equation given in description of invention. EFFECT: improved validity of measurement results, improved electric safety due to precise determination of measurement time as result of continuous balancing of bridge at any step of device operation, timely measurement at slow variation of R_и.э, generation of noise-immune signals indicating necessity of subsequent measurements or transients in main under check. 2 cl, 1 dwg