How to create a factory-like grounding system at home
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The house only has live and neutral wires; there is no ground wire. It’s a rural homestead. For some reasons, now a ground wire similar to that in factories is needed. How can it be created?
Set up a grounding level next to the house
If the requirements are not high, it’s sufficient to build it using angle iron; sometimes it’s necessary to add some salt to the soil as well.
So after it’s buried, how can we check to see if the work was done properly? What equipment is used, and which standards apply for such inspections?
What value should the ground resistance be controlled at?
Some people told me 100 ohms, while others said 5 ohms
The grounding resistance is generally determined based on the grounding requirements of electrical equipment. The general requirement is 4 ohms; for higher requirements, it is 1 ohm, and for lower requirements, it is 15 ohms. Ground resistance is tested using a ground resistance tester, a specialized device for this purpose. The older models are of the hand-crank type, similar to megohmmeters, while the newer ones are digital. The ground resistance tester has three grounding electrodes, which are connected to the three terminals of the tester.
After completing the grounding, use a megohmmeter to check the resistance value. Generally, the grounding resistance of electrical equipment should be less than 10 ohms, while for devices with automated control, it should be less than 4 ohms.
Take a look at the \"SHT_3081-2003_Petroleum and Chemical Industry Instrument Grounding Design Specifications\" and make some minor adjustments as well.
Use a ground resistance tester to measure the resistance of the grounding electrode; it’s feasible to do this, and the cost is around a few hundred yuan – it can be purchased on Taobao. 1. The resistance of the independent lightning protection grounding system should be less than or equal to 10 ohms ； 2. The resistance of the independent safety protection grounding system should be less than or equal to 4 ohms ； 3. The grounding resistance for independent communication systems should be less than or equal to 4 ohms ； 4. The resistance of the independent DC operating ground connection should be less than or equal to 4 ohms ； 5. The anti-static grounding resistance is generally required to be less than or equal to 100 ohms ； 6. The common grounding electrode (combined grounding) should have a grounding resistance of no more than 1 ohm. The factory underwent maintenance some time ago, involving the grounding of all tanks and buildings throughout the facility. For ground resistance, inserting a single steel bar may result in a high resistance value; if possible, insert several bars and weld their upper ends together, similar to parallel connection of resistors, in order to reduce the overall resistance value. The number of bars to use depends on the requirements. The grounding electrodes led out from ordinary building foundations can generally meet the requirements.