How to make ground in the country with their own hands
Summer houses ceased to be just a gardenbuildings for summer holidays, and turned into a full-fledged suburban housing. At the same time we have equipped them with all the creature comforts, including mnogomoschnuyu electrical, such as refrigerators, washing machines, microwaves and more. All these devices facilitate us life, but are a source of increased danger. Therefore, do not forget the ground in the country.
- The operating principle of the ground
- What should be grounded
- How to protect cottage
- Personal example of a device
The operating principle of the ground
A little touch on the theory, to understand why we bother with the equipment grounding circuit.
Electric current that flows through the wire and is suitable for consuming devices, tends to flow in the direction of least resistance. This is very similar to the way water behaves.
What happens if the insulation of the appliancebroken? The current will be looking for a place where the smallest resistance, tends to zero. If grounding is not equipped, a weak spot and begins to spark to shoot lightning. Well, if the fireworks stop machine. If the process is smoldering, low-current, fuse fail. Then, when you touch the device a person will receive an electric shock that may have unfavorable consequences. And if he still has the legs and suddenly will be wet at all scary to imagine what will happen.
To protect the inhabitants of the house and electrical appliances from the current breakdown, it is necessary to take the place of least resistance. That place is the earth, the soil.
What should be grounded
The resistance of the grounding circuit should bemuch less than the resistance of the human body. Without going into the details of the jungle, we assume that it must be less than 4 ohms. In some sources you can find other figures: 0.5 ohms, 30 ohms and 60 ohms even. More detailed information is gleaned in the SAE or contact the electricity supply company. But we will proceed from the fact that the smaller the better.
The depth of the grounding electrodes depends on many factors, such as soil structure, the level of ground water and climatic conditions.
Important! The general rule is: the more the soil is saturated with water, the shallower should score electrodes and place them in smaller increments from one another.
Peat has the lowest resistivity- 20 Ohm * m, black earth and clay is slightly larger, but sandy loam - already 150 ohm * m. Sand is the most dangerous - the resistance is 500 to 1,000 Ohm * m, depending on the water level occurrence.
The depth of penetration of the electrodes can be from 1.5 m to 3 m or more. The amount depends on how close the water. If the level is within 2.5 m, it is enough to bury 1.5 - 2 m.
The distance between the electrodes in the circuit may be from 1.2 m to 3 m.
The number of electrodes depends on the circuitthe resistance of the soil and can be 3 pieces, forming a triangle. If such a structure is not enough, the number of electrodes can be increased by connecting them to an existing circuit.
The distance from the circuit to the house must not be too large. Enough 3 - 5 m.
Important! The most correct and appropriate solution is to contact your local department of energy management. Ask the ordinary electricians as settling ground loop in this particular region. What are the essential characteristics, how deep to set how far the bear. The more that you will still need their services, to check the resistance of the resulting ground loop on your site.
How to protect cottage
The most common way of arrangementground loop is a triangle with vertices in the steel electrodes, driven into the ground to a depth of 1.5 to 3 m. The entire circuit should be placed below the depth of soil freezing.
Connecting the electrodes to each other can be steelstrips or fittings, be sure to only welding. From one of the electrodes is necessary to force the steel strip to the enclosure, simply shield. If the distance between home and the circuit is too large, the shield can be made from cable which is then secured to the electrode by means of bolts.
What can be used as electrodes:
- Steel Area 4 * 4 mm minimum.
- Round steel (rebar) - 10 - 12 mm2.
- A steel pipe with a wall thickness - 3.5 mm.
- The steel strip with a minimum area of 50 mm2, for example, 4 * 12 mm.
The main criterion in choosing the material forsectional area of the electrodes used, it must be at least 1.5 cm2, and the convenience of clogging in the ground. Those. it can be any sharp steel conductor rod, at least I-beams, even though profiled tube. The main thing is to sharpen the end to make it easier was part of the soil. Corner can be cut at an angle grinder, making a sharp wedge. Valves have to be smooth, nereflennoy. Otherwise, contact with the ground electrode is not sufficiently durable. Voids, which will reduce the resistance of the circuit.
Information for those who do not wish to useavailable materials and used to do everything thoroughly and expensive, there is the opportunity to purchase ready-made kit, which is designed for the arrangement of ground loop. It is a copper covered steel electrodes to 1 meter in length, collected by a threaded connection. It is convenient, efficient and relatively cheap. But if you can, take advantage of this option.
As straps connecting the electrodes betweenIt is possible to use steel strips 40 * 4 mm or valve 12 - 14 mm. The main criterion is the minimum cross-section of 50 mm2. And do not forget, connected only by welding.
Personal example of a device
First decide on a material and design of the grounding circuit. Embodiments have been described above. We'll show you how to make a grounding in the form of a triangle.
Then choose the location, convenient and close to the control cabinet, the best is the distance of 10 meters.
- Digs a trench in the form of an equilateral triangle. The depth should be at least 0.8 m, preferably 1 m. Width 0.5 m will suffice. Additionally, we dig a trench leading to the power cabinet.
- At the apex of the triangle trying to drive the electrodes, if it allows the soil density. Otherwise we are drilling wells.
- Electrodes should protrude above the ground,to be able to weld the strip thereto. If we drilled the well, and not scored rods fall asleep hole with soil, mixed with salt. This will significantly reduce the resistance of the circuit. And though the corrosion in this case will increase, grounding will last for years to come.
- Band welded to the electrodes, forming a closed triangle, one band conducting from the electrode to the power cabinet.
- Fix the strip to the shield or ground wire screw at least 10 mm in diameter. Be sure to strip the bolt welds.
- Check the resistance of the grounding circuit. To do this you will need a special device - Ohmmeter. It is quite expensive to buy it to make once in ten years, measurements, and then once in a lifetime, it is meaningless. Therefore, we invite people from energy management or ad hoc organization. They will check the resistance and will make the appropriate documentation. The indicator should be less than 4 ohms. If there are, it is necessary to increase the grounding circuit, by driving more electrodes and connecting them with the existing ones.
- If the circuit resistance were satisfied, we fall asleep trench. We use only homogeneous soil, no construction debris or rubble.
Important! A little trick: Some craftsmen are advised before the arrival of people of good energy management pour water circuit ground. This will reduce the resistance. Problems with access to the documentation will not be. Though the idea is quite interesting: experts advise really hot days regularly watered it, but we are not for the sake of command "start trouble." Therefore it is better to make a grounding quality to its resistance even under drought conditions were optimal.
Note that if you are the owner of the charminghouse in the mountains, This is all you can not come. For ground loop in rocky soil using horizontal or radial electrodes. They can be arranged in a grid or diverging rays, stepping from 3 to 10 m. A good option is to use electrolytic grounding. Though expensive, but very effective.
As you can see, equip ground with their hands not be easy. The most difficult part is to determine the length of the electrodes, their number and spacing. The rest - a trick.