The story of proper grounding starts with a story about a shovel, a ditch and a contour from a steel corner, but let's start from a different point. Recall why, in fact, the process is organized, and, accordingly, we discuss the necessary measures. The answer about the reasons for the need for grounding in the apartment is not obvious, as it seems initially.
Grounding for household appliances
The Western world is designed so that the input filters of devices go to grounding in the apartment. Voltage harmonics flow down here. This is a coarse and pre-filtered ground loop. Often carried one or two capacitors. In the latter case, their common point goes to ground in the apartment through the housing. If this is not done, a washing machine may break down. It is known, by the way, that post-Soviet drills of Russian production were shocked if both pins of the plug were pressed against the skin. In this case, a similar thing can happen, but the harmonics go to the case, then to the ground loop in the apartment.
The washing machine connected to the network carries a voltage of 65 V, but the current is low and there are no deaths in the practice of using foreign equipment. But during the breakdown of the insulation of the heating element on the case, we risk to feel an electric shock if we fail unsuccessfully with two hands: the first for the washing machine, and the second for the sink tap. Grounding in the apartment is done so that any voltage leaks into the soil. If we talk about the washing machine, according to the rules, it is connected via a differential-type residual current device, and it will not come to knocking out stoppers.
Another reason for the organization of the ground loop in the apartment is the protection of equipment. We have seen above that she can take enough damage. Even more invisible factors can do more damage. These are voltage drops. At a specific frequency, instability of internal constant and variable supply voltages will arise, other factors are possible. The electronic brain of a washing machine( timer plus logic and control) can be individually up to 80-90% of the value of the goods. It is clear that few people want to part with such a sum, and poor filtration can be the cause of the failure of an expensive module. If the housing is grounded, the operating conditions of equipment, especially electronic, become better. This is easy to check if you organize the grounding of a simple personal computer correctly: the coolers will turn quieter due to the stability of the power supply.
Finally, human life. If, for example, a breaker breaks through the heating element, then the current would infinitely increase until the elements of the device are burned. Eyewitnesses say that the most expensive is the first to fail. The fuses are last burned. Normal operation of the RCD is not possible without a grounding circuit. For the reason that a power outage will occur if there is a leak: if someone is shocked.
The main difficulty of electronics in its electromagnetic insecurity. Almost all communications, including modems, operate at a critical frequency of 2.4 GHz; at this wave, water absorbs the energy of the ether wave. As it is easy to guess, this is inconvenient for a person. May cause cancer, insomnia, nervous disorders and more. The metal case of the radiating devices serves as a screen. If the shield is not properly grounded, half of the radiation comes out.
What to do to organize the grounding at home
Firstly, in rooms where there is moisture, all devices are combined with a protective zanulenym. This means that the equipment housings must be electrically connected. The difficulty is solved by the appropriate supply to the side terminal of the zero socket. For this, it is permissible to take a neutral, but not encouraged. The zero wire is located in the ground. According to the TN-C-S system, grounding is allowed to be combined in the area of the lightning circuit. And there is a similar under the houses, even built in the USSR.
A number of old devices, for example, an iron, do not have the ability to connect a case. Grounding electrical installations in a similar case is a primitive way. Inside the iron there is a screw on the sole, electrically extending to the side terminal of the socket. If you open 21130, then this is the first thing we stumble upon. Look at the picture and think about how and where to attach a similar structure. And if there is no possibility to weld it, drill a neat hole, insert a bolt with a nut and place a terminal behind the eyelet. The wire will have to be replaced completely, take it from any “rat”, carrying, other( already broken) household appliance. When working with a power above 1 kW do not try to use collapsible plugs - it will not bring to good.
Ask - why ground the iron. If we talk about modern models, steam is used there. And the combination of electricity and water is not safe. We have to think about creating grounding. As for the old Soviet models, then we are talking about, besides safety, about radiation. The frequency of the industrial network of 50 Hz is harmful to humans. It must be shielded from the hands and other parts of the body of the housewife.
From the above it is clear what to do with small Chinese black and white TVs, and we return to personal computers. The system unit consists of panels that are instructed on a single chassis of aluminum, silumin, and other alloys of similar nature. The difficulty is that the parts are painted. What to do in such a case? We take the tester and call up the parts( assembled system unit) with the power supply case( it sticks out in the area of the cord entrance through an extensive figured notch).If the signal passes( and on the DC tester), then everything is in order. Exactly the joints will behave at high frequencies.
It happens that the bay( bay) for the installation of a DVD-drive or other device on the front panel has already been used. This means that the aluminum plate is broken off inside, and the outside is covered with a plastic cover. In such a case, the space needs to be sealed. Or in the face of the user will shine the radiation of the processor and other electronic parts of the system unit. It is not enough to make the grounding in the apartment, it is necessary to ensure the closed contours of the housings of the radiating devices. It is easier to cut a plate of the desired shape from conductive material and strengthen it in place so that electrical contact with the rest of the body is formed.
If there is no ground loop in the house, you need to think of it. Terminals on the outlet combine with a neutral wire. If the installation of electricians was carried out according to the rules, the phase is on the left, the zero is on the right. It also needs to be combined with the discussed terminals. For example, with the help of a short jumper from a copper conductor of large cross section. To check the correctness of the installation, there are two ways:
- The first concerns a special probe used by electricians. This is a small screwdriver with a handle of transparent glass, inside there is a small LED.When the slot touches the conductive power cord, a bright light lights up. This means that they have touched the phase. It should be located on the right, and it is not necessary to connect it to the ground loop of the outlet. Otherwise, the devices in the house will be under dangerous voltage.
- The second method is more subtle. Eyewitnesses noticed that the computer power filter does not light up if zero is present on the ground lobe. We turn off consumers from it and turn this carrier into a converted outlet. If when the button I was pressed, the light caught fire, the installation was carried out correctly. But we cannot recommend this technique as an official one, just please note that there is a similar way to check if the grounding is correct.
How to make a ground loop in the garage
Already said enough about the grounding and zeroing of electrical installations in the apartment, but how to do it in the garage? There, the voltage jumps heavily, and apply hand to the soil. To dig in the subfield circuit, connect the ground to the shield? Knowing how the wiring is laid - between the pillars, the incomprehensible old wire - this is likely to be the best option. In most cases, it is easier to disassemble the floor, dig a hole at a depth of at least 1.5 meters and start grounding.
To reduce the size of the work, steel stakes are driven into the bottom of the groove and a grillage is made from a corner profile. This is reminiscent of the pile foundation of concrete, on which most houses in Russia stand. It is much more difficult to connect the ground to the panel, if the floor is already concreted. It is recommended to use a cellar, it is permissible to drive stakes of steel into the walls of the cellar. Usually this room is located about 2.5 meters below the ground, which will ensure normal contact.
How to measure the grounding resistance to ensure the high quality of the work done:
- Take an ordinary cartridge for a chandelier( price 25 rubles).
- Screw the light bulb( energy saving).
- Connect the electrical wiring.
- One end joins the ground loop.
- Plug the other end into the outlet phase( identify with a dipstick).
If the light is on, the work is successful, but you need to evaluate the resistance. Measure the voltage on the light bulb. If it is not too different from the voltage in the outlet( measured separately), then the ground loop is installed soundly. Otherwise, you will have to score more stakes, increase the area and length of the system. Please note that at all points the contour should be isolated from places where people can be found. To install the grounding did not go sideways.
If we act according to science, we measure the grounding resistance with the help of a special device. And if we are talking about production purposes, it is necessary. For example, there is a GOST method with a reference ground loop. There is not much need for equipment. But where to get a good ground reference circuit( resistance is within the normal range, which is about 3 ohms) to the average driver.
Already shown above how to measure grounding. We add that the resulting voltage on the bulb must be subtracted from the mains, and then it is divided by the current in the line. It turns out the true resistance of the ground loop. But the spiral of the bulb carries the reactive load of the alternating current due to the presence of coils. To measure the resistance of a simple tester will not work. Par will come out wrong. We can make it wiser: in advance, calculate according to Ohm’s law on some stand. Methods for determining the grounding enough without the use of this equipment.