The use of digital multimeter to check whether the line is grounded or not
Put the digital multimeter to the resistance file 20K or more, respectively, to measure the insulation between phases.
Measurement line grounding, line to the shell of the power equipment to measure, if the line grounding touches the equipment shell, resistance value is usually more than a few hundred ohms, or even zero.
I measure the crane control line, is so measured.
If you simply measure the line to earth resistance, the multimeter is not very easy to measure, it is recommended to use a resistance meter to measure.
Judge whether the ground jack is grounded method one:
1, first divided into fire wire, zero wire. Ground: the multimeter to AC voltage gear, and gear higher than 220 V. The red pen into the voltage hole, the black pen is not inserted, and then insert the red pen into one of the socket jacks, observe the readings. The largest reading is for the firewire, smaller readings for the zero line, readings basically did not move for the ground line. If there are 2 readings of small, a reading of large that the earth wire is not grounded, the earth wire is also connected to the zero wire. The second step behind does not need to be measured.
2, measurement of the ground: separated out of the fire, zero, ground, the multimeter or just now in the gear does not move (AC gear 220V or more), red and black pens were inserted into the voltage holes and COM holes. Measured with 2 pens, respectively, the fire wire to the zero line voltage, the fire wire to the ground voltage, if the 2 voltage values are basically the same, indicating that the ground is grounded; if the fire wire to the ground voltage value is basically zero or a particularly small description of the ground is not grounded.
Method two:
1, the digital multimeter to the resistance file 20K or more, respectively, to measure the insulation between the phases.
2, measuring line grounding, line measurement of the shell of the power equipment, if the line grounding touches the shell of the equipment, the resistance value is usually more than a few hundred ohms, or even zero.
3, measuring crane control line, is so measured.
4, if you simply measure the line to earth resistance, multimeter is not very easy to measure, it is recommended to use a resistance meter for measurement.
