Steps to differentiate between ground and zero using a multimeter:
1, take out the multimeter, the multimeter switch to AC 250V or 500V gear, specific regulation gear specific analysis.
2, with the red pen on the fire wire, black pen on the other two lines, for insurance purposes, it is best to use the multimeter resistance file and then you measured out of the ground line with your building in the rebar and then measured, there should be a not too big resistance (or access, due to the grounding resistance of each building is different, so the measured resistance resistance value is different).
3,, when the multimeter reading appears high value, the measured for the fire wire. And a meter pen with a hand holding the metal head, a meter pen to touch the three lines, that one of them is going to have a swing.
4, if the needle does not move, the multimeter switch to the lowest gear, still no obvious reading, the measured point for the zero line.
5, if there is no grounded place can also be used in the following way: the multimeter switch to AC voltage gear, any one of the pens connected to the power supply to be measured, the hand index finger and thumb pinch the other pen, if the multimeter has readings. If the multimeter has a reading, the measured point is the fire line; if the multimeter pointer does not move, it is the zero line or ground line.
Extended information:
1, the relationship between the fire wire and the zero line
Fire and zero line can not be directly connected together, if connected together will cause a short circuit, burn electrical appliances, as well as personal injury, so the need to connect loads between the fire and zero line. Fire wire and zero wire can form 220V voltage, the load can be light bulbs, electric blankets and other electrical appliances that require 220V rated voltage.
2, the relationship between the zero line and the ground line
When we are servicing the circuit, the voltage between the zero line and the fire line is 220V, the voltage between the ground line and the fire line is also 220V, but the ground line can not be used as a zero line, because the two roles are not the same, the role of the zero line is the main fire line and fire line to form a circuit, the role of the ground line is to protect electrical appliances to prevent the destruction of the lightning strike, the fire line and the ground can not be directly connected to the ground line, which will also cause the circuit to be shorted out, the possibility of human The possibility of human electric shock injury.
