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怎样用万用表检查线路是短路还是接地?

最简单的方法就是用万用表测量地线的电流,如果地线存在电流,那么就是相线接地了。如果检测地线没有明显的电流值,在确认无电器设备工作的情况下检测零线有没有电流,如果有电流那么就是相线相间短路或者相线对零线短路。

The simplest way is to measure the current of the ground with a multimeter, and if there is a current in the ground, then the phase line is grounded. If there is no obvious current value in the detection ground, there is no current in the detection of the zero line in the case of confirming that there is no electrical equipment working, and if there is a current, then it is a phase-to-phase short circuit or a phase-to-neutral short circuit.这种测量方式是最为直接的,如果已经断电,无法检测电流的情况下,可以考虑用万用表的阻值档去检查零线和火线之间的电阻、零线和地线之间的电阻、火线和零线之间的电阻,当然如果是380V的供电电源你还需要检查火线之间的相间电阻。

This measurement method is the most direct, if the power has been cut off, can not detect the current, you can consider using the multimeter resistance file to check the resistance between the zero line and the fire wire, the resistance between the zero line and the ground wire, the resistance between the fire line and the zero line, of course, if it is a 380V power supply you also need to check the phase resistance between the fire wire.当然不同的供电方式,检查的出来的结论是不一样的,在TT供电系统中零线在入户前需要单独进行接地,电气设备的金属外壳一样需要单独的接地,这个时候测量零线和地线之间的电阻阻值正常情况下是比较低的,也就是说零线和地线与火线短路你检查的结果是零线与火线、地线与火线之间的电阻都比较低,可以将零线入户时的接地取掉再进行检查。

Of course, different power supply methods, the conclusion of the inspection is not the same, in the TT power supply system the zero line in the household before entering the home needs to be grounded separately, the metal shell of the electrical equipment also needs to be grounded separately, this time the resistance between the measurement of the zero line and the ground wire is normally relatively low, that is to say, the zero line and the ground wire and the fire wire short circuit You check the result is that the resistance between the zero line and the fire line, the ground wire and the fire wire are relatively low, and the ground between the zero line when entering the house is removed and then checked.在TN-S供电系统中是三相五线制,有三根火线、地线、零线,这个时候去检查零线和地线之间会存在一定的电阻阻值,同样的方法检查的时候需要去切掉地线或零线的进行,再分别用万用表去检查零线与火线、地线与火线、火线相间之间的阻值,来判断是哪个地方短路。

In the TN-S power supply system is a three-phase five-wire system, there are three fire wires, ground wires, zero lines, this time to check the zero line and ground wire between the existence of a certain resistance value, the same method of inspection needs to cut off the ground line or zero line, and then use the multimeter to check the resistance between the zero line and the fire line, the ground line and the fire line, the fire line between the resistance, to determine which place is short circuit.

如果是TN-C系统就比较简单了,零线和地线是一根线PEN,只需要去检查火线相间、PEN线与火线之间的电阻阻值即可。

If it is a TN-C system, it is relatively simple, the zero line and the ground wire are a line PEN, you only need to check the resistance between the fire wire phase, the PEN line and the fire wire.另外需要说明下:检查短路最有效的工具并不是万用表,应该使用对应电压等级的摇表来检查。

In addition, it should be noted that the most effective tool for checking short circuits is not a multimeter, and a rocker meter corresponding to the voltage level should be used to check.