How to use a multimeter to measure whether the circuit is grounded or not? First of all, regardless of measuring any line or equipment, the voltage should be measured first to ensure that it is safe and voltage-free, and then other measurements should be made. If it is a capacitor or a capacitive reactance device, it should be discharged first, and then the safety and voltage-free should be determined. Then adjust the gear of the multimeter to the gear of 2000 megaohms, with one end of the probe touching the grounding body or the metal shell of the equipment, and the other probe touching the normally charged conductor of the equipment or line. If the resistance is less than 0.5 megaohms, it is grounded. Generally, the leakage protector greater than 0.5 megohm and 30 mA will not trip, so it is generally considered that the line or equipment is not grounded. But it also depends on the working voltage of the equipment or line or various technical requirements.
In daily life, as for the wide range of circuits, I don't know what kind of circuits you mean, such as electronic circuits, electric circuits for transmitting voltage, motor circuits, etc. Take these three commonly used circuits as examples to talk about how to use mulmeter to block the measurement of grounding.
First, the electronic circuit, in general, the measuring electronic circuit is universal.
The gear position of the meter is the maximum gear position of 10K. At this time, the measured resistance value is almost close to 10k, and the pointer is inched, and then the stylus is switched to measure. Some electrical appliances will be different after the stylus is switched, and the difference will be less. Porque en el circuito electrónico , en orden para resistir alta frecuencia interferencia, a alta frecuencia condensador está instalado a tierra 2c así es normal para medir el suelo con un cierto valor. Por lo tanto, personas sentir entumecer en ordinario tiempos. Este tipo de circuito puede 't ser medido por agitación tabla, que dañará electrónico partes.
Second, the voltage transmission circuit, take the household lighting circuit as an example. Before measurement, the power switch should be turned off first, and at the same time, the switches of all electrical appliances should be turned off, and then the grounding situation should be measured. If the resistance of the mesuring circuit to the ground is blocked by a a mulmeter, the resistance of the zero line of el vivo cable debería ser infinito. Par si el multímetro es usado para medir este circuito, it es lejos de suficiente, porque el voltaje de el laminado batería en el multímetro es sonly 9 voltios, and the lighting voltage is about 220 volts, which is conditional.
Third, the motor circuit is not measured with a multímetro. It is also measured with a {{{0}}volt megger. The resistance of the coil circuit to the ground is also greater than 0.5 megohms, which is safe. If it is a newly wound motor coil, the resistance to the ground must be greater than 10 megohms. Por lo tanto, cada uno circuito tiene diferentes requisitos para la resistencia de la tierra, y el requisito de alto voltaje has a a a aislamiento resistencia a la tierra.
