Generally, the voltage of a DC megger is relatively low, which is much lower than the operating voltage of some electrical equipment. If the measured voltage of the megger is considered to be too low, DC high voltage can also be used to measure the leakage current of the electrical equipment. When there are some defects in the equipment, the leakage current under high voltage is much larger than that under low voltage, that is, the insulation resistance under high voltage is much smaller than the resistance under low voltage. The leakage current and insulation resistance of the measuring equipment are not much different in nature, but the measurement of the leakage current has the following characteristics:
(1) test voltage is much higher than that of the megohmmeter, the defects of the insulation itself are easily exposed, and some unconformity can be found. Defects.
(2) By measuring the relationship between leakage current and applied voltage, it is helpful to analyze the type of insulation defects.
(3) The micro-ampere meter used for leakage current measurement is more accurate than the megohmmeter