How to use a multimeter to measure if the ground is good or bad
People who understand electricity know that the grounding wire is important, grounding can play a life-saving role in important times. Grounding wire to produce a role, that is to be wired from the three-hole socket grounding hole, and then to the family grounding trunk, and then to the whole building grounding trunk, and then to the grounding pole to keep connected, the general grounding resistance should be less than 4 ohms.
How to use a multimeter to measure whether the grounding is good or bad? In general, the use of multimeter resistance gear, a pen connected to the socket grounding holes, one end connected to the buried rebar, iron, and even into the home of the steel water pipe can be, if the measured resistance value is relatively small (in a few ohms to dozens of ohms can be, because of this measurement is only roughly, we can not guarantee that the buried rebar, into the home of the steel water pipe is well grounded), then basically can be determined that grounding wire is effective. If the measured resistance in the hundreds of ohms or even a few megohms, then you can basically judge the grounding wire is invalid. Of course, if you want to measure accurately, it is necessary to use a grounding shaking table or grounding resistance tester to test the grounding resistance.
Grounding failure is due to the following reasons, one is the socket grounding pole is not grounded or grounding wire false connection. Second, there is a broken circuit in the middle of the grounding wire. Third, the grounding wire is not connected to the grounding electrode in a limited way. Fourth, there is no grounding electrode at all.
However, is the earth wire connected and effective in home electricity. The answer should be no.
I know most of the rural electricity, there is no grounding this set, how the grid line is generally zero fire two lines, the rural household grounding is generally virtually non-existent. General rural are self-built houses, basically have no awareness of their own to bury the grounding pole, and then the plumbing and electrical installation of rural self-built houses over again are some of the earth electrician, will not be interesting to do the grounding, and finally their own installation of grounding poles, grounding wires, will increase the cost of materials and labour costs. Regulate the safety of electricity in rural areas, is a relatively long process.
