What is grounding, what does it give and why is it needed in the outlet

That some household appliances must be grounded, almost everyone knows. But which ones are needed, and which does not require grounding? The heating boiler is definitely needed - the master requires it during the start-up work. A washing machine or vacuum cleaner, meat grinder or microwave? It seems not. Or is it necessary? To answer this question, you must first understand what grounding is and why it is generally needed.

What is leakage current and how dangerous it is

All electrical appliances are powered by a voltage of one magnitude or another. The player, for example, works from three volts, the headlights of a car - from 12 volts. Household appliances require voltage

220 volt. Low voltage is safe for humans, but starting from 36 volts and above, it already poses a threat. Everyone knows that you cannot climb into a household outlet with a plug or a paper clip - it can kill. Namely, you connect almost all household electrical appliances to this outlet.

If these devices are in good working order, then their operation is absolutely safe. Now imagine that the insulation on the supply wire was frayed from vibration somewhere in the bowels of the washing machine and the bare metal touched the metal casing of the device. There was a hit of mains voltage on this very casing. So far nothing serious has been noticed - the unit erases, the lights are blinking. But as soon as you touch the body of the car, how current rushes to youand through you into the ground. You have come under life-threatening stress with all the ensuing consequences. The same trouble can happen if water accidentally gets inside the appliance, which, as you know, conducts an electric current *.

*Actually leakage current is a broader concept. The current can "flow" not only through the human body and not necessarily into the ground. In this situation, this is irrelevant.

As soon as you touch the faulty device, current begins to flow through you.

Is it possible to protect against leakage current

Is it possible to protect against a leakage current through the body, which may appear at any time? The worst thing is that it is impossible to predict such a situation - the voltage on the casing of the device can appear at any second. Water spilled on a coffee maker or a meat grinder, vibrations, electrical breakdown of poor-quality insulation, failure of electrical circuit elements - all this is unpredictable and at the same time deadly. There is only one way out - to create a system of protection that will be on the alert all the time. And such a system exists, and its name is grounding.

What is grounding for and where to get it

The simplest and most reliable option for protection against leakage current is to electrically connect the metal body of the device to the ground. In this case, as soon as voltage appears on the casing of the electrical appliance, it immediately goes into the ground. If the leakage current is small, then even faulty equipment will continue to work without posing a threat to humans. Such situations are not uncommon in the operation of most household appliances, but you do not even know about it. If the insulation breakdown is serious, then too much leakage current will cause the circuit breaker in the electrical panel or burns out the plugs. But in any case, faulty, but grounded equipment will not pose the slightest threat to life.

If the casing of the electrical appliance is grounded, then the voltage that has hit it will "drain" into the ground along the protective wire

Now it's time to consider the types of grounding. There are two of them:

1. Artificial.
2. Natural.

Artificial grounding

This type of protection appears as a result of performing special operations aimed specifically at creating grounding. For example, metal structures are dug into the ground and a contour is created. At the same time, this circuit does not carry any other functions, except for reliable electrical contact with the ground. Such systems are created almost near every industrial enterprise, apartment building or electrical substation. They are not visible, but they are definitely there.

Natural grounding

In such designs, electrical contact with the ground appears as a side effect. Water pipes, for example, lie in the ground. A metal fence or iron lamppost is dug into the ground. The main purpose of all these structures seems to be different, but they can also perform the functions of grounding.

It is quite understandable that natural grounding will not have the same reliability as an artificial one. The water pipe can be cut by a neighbor from below or "uprooted" from the trench by water utility workers during scheduled repairs. If the water supply route lies in gutters, then in dry weather contact with the ground, which seemed to be good yesterday, may disappear. A metal fence or a lamppost can be dismantled by DEU employees or the same neighbor.

Artificial grounding, unlike natural, is performed specifically to ensure safety or create a zero point for powering equipment. It is made by specialists armed with electrical engineering knowledge and the appropriate tools. In addition, since the artificial contour is usually hidden in the ground and is not intended for anything else, the chances of it being dismantled are minimal. Plumbers do not need it, neighbors do not know about it, and electricians digging a ground loop with their own hands without taking special measures have not yet been born.

From the above, it is quite obvious that to ensure complete safety, it is necessary to use artificial grounding. Natural is suitable only if you are 100% sure that the post located in your garden will not knock down drunk driver, and the water pipes are your private property, lie in the bare ground and on your territory.

How to ground an electrical appliance

So, you have purchased a washing machine or gas heating boiler. How to ground them? First of all, you need to find the grounding itself.

Where to find ready-made grounding

As mentioned above, almost all apartment buildings have their own outline. This loop is connected to the main switchboard housing and, most importantly, to each driveway switchboard. Even tenants of the ninth floor have a contour literally under the door - a floor metal shield with electricity meters.

If you look inside such a shield (just look, do not climb there with pliers!), Then you will surely see a lot of wires bolted directly to the body of the shield. Here it is, grounding! If the casing of the same boiler is connected to such a bolt, then this casing will be reliably protected from appearing on it voltage, which means that the operation of the device will be completely safe even if malfunction.

The situation is somewhat worse for the owners of private houses, where there may not be a regular outline. There are two options here - to create a contour artificially or to use a natural one. You read about the second type above and whether or not you should connect to it is your choice. It is safer, of course, to make a ground loop on your own, especially since it is not difficult at all. But if you still decide to use natural grounding, then this photo will help you correctly connect to it:

Such a connection is permissible only if you are sure of a reliable and long-term electrical connection of the water supply to the ground.

How to make grounding with your own hands

To make the simplest outline, you will need a massive metal object. It can be an old crumpled barrel, a large thick-walled pan (not enameled), a bicycle frame, pieces of reinforcement welded together, etc. First of all, to this object, which will play the role of a circuit, it is necessary to securely attach a conductor a couple of meters long.

Suitable for its manufacture thick iron wire (for example, "wire rod") with a diameter of 8 mm and above. You can take a long armature, pipe, corner, iron strip. Attach the wire to the future contour using welding or a bolt and nut. The reliability and durability of this connection will determine the reliability of the grounding as a whole. To prevent the connection from rusting, paint it with any paint or fill it with bitumen.

Now it's time to do manual labor. Take a shovel and dig a hole large enough to fit your barrel, frame, or whatever you have chosen as the outline. The depth of the pit is at least 1.5 m, and for sandy soil - 2.5 m. You put your circuit in it, and take the conductor out. It remains to bury the hole, compact the earth tightly and pour water over it for better electrical contact, like an ordinary tree. The ground loop is ready. You did not forget to drill a hole for the bolt on the protruding part of the conductor, did you?

How to connect an electrical appliance to ground

Depending on the design of the appliance, two methods of grounding are used:

1. For a special technological clamp.
2. With a special plug.

The first option is used in stationary structures, that is, in those that you cannot carry. Gas boiler, electric titanium, lathe, etc. For this, such equipment has a special bolt with the appropriate designation:

Grounding bolt on the body of the electrical equipment

Such a connection is reliable, visual, and durable. But what about, say, a microwave oven or a computer? After all, they are often rearranged from place to place, and for this you will have to not only constantly turn the bolts, but also carry a grounding cable around the house. Household appliances designers, together with power engineers, solved this issue simply and elegantly. Take a look at the modern outlet and plug:

Grounding contacts in modern wall outlets and plugs

You have probably noticed more than once the contacts indicated by the arrows. What are they for? Thissecond contactto which the ground is connected in the socket, and the body of the device in the plug. By inserting the plug into the outlet, you not only apply voltage to the meat grinder or washing machine, but also ground them!

Unlike conventional plugs and sockets, these have three wires:

• 1, 2- feeding;
• 3- grounding.

This design of the connectors makes it easy and safe to use portable electrical appliances without worrying about their grounding. But, of course, only if your sockets throughout the house have a ground wire.

So, what is the grounding in the outlet for? For the same as usual - for safety. But using it, you see, is much more convenient.

Why do some electrical appliances not have a grounding plug? The answer is simple - they don't need it. If the housing, say, of a heater or hair dryer is made of plastic, then even if the insulation breaks down, you will not be able to get under voltage without disassembling the device itself. Many power tools do not require grounding. For example, electric drills and grinders equipped with a conventional fork are very widespread. This also includes soldering irons. In them, electrical safety is ensured by double insulation.

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