Grounding 220 v in a private house: what is it for and how to do it right with your own hands

When living in an apartment building, there are no problems with grounding - each storey electrical panel has a ready-made grounding loop. But if you live in a private house or in a country house, inviting paid specialists is not at all necessary, because you can make a grounding device in a private house with your own hands. 220 V is a strong supply of current, therefore it is dangerous to ignore the grounding.

What is grounding for?

Before you start making your own grounding loop, you need to figure it out why do you need to ground electrical appliances at all. This will help you to take a responsible attitude both to the choice of the circuit and materials of the ground loop, and to the process of its manufacture.

Anti-interference

The problem of interference mainly affects owners of high-quality sound reproduction / sound recording equipment and PCs. Line filters built into such devices "collect" impulse noise from the mains and send them to the device chassis, and in the case of a PC, to a metal casing.

Fragment of the PC power supply circuit (the filter is circled in red)

If the housing of the device is not connected to earth (PE terminal on the mains plug), then all interference remains on the housing and create an electromagnetic field around it, which interferes with signal wires, microphones, headphones.

Anyone who has encountered such a problem knows that getting rid of such interference is difficult. No shielding or supercables can solve the problem - interference from the case penetrates into external devices even through the shielding braid of the connecting wire. But it is worth connecting the case of the same PC with a centralized heating battery or water supply, and the background in the headphones or speakers disappears in the most miraculous way.

How to avoid electric shock

If the interference with sound reproduction is, albeit serious, but just an inconvenience, then the voltage that for one reason or another hit the device's casing can be life threatening. The worst part is that equipment malfunction during insulation breakdown on the case often does not manifest itself in any way - the device works and looks absolutely correct. But as soon as a person touches the casing of the same washing machine, a current begins to flow through his body into the ground (damp floor, tiles, concrete), the value of which, even in 50-80 mA, is fatal:

Electric shock to a person when touching faulty equipment

To eliminate such a situation, it is enough to connect the body of the device to the ground, and even a faulty washing machine or dishwasher will not pose any threat to a person. In case of incomplete breakdown, the voltage from the casing will simply drain into the ground through a special bus, while a complete breakdown of insulation will cause short circuit and tripping of protective equipment - a fuse in the device, a circuit breaker on a staircase or in a house shield.

It is completely safe to touch faulty but grounded equipment

For a quick and easy connection to earth, all devices requiring an earth connection are equipped with a dedicated mains plug with grounding prongs or a grounding lug.

Contacts marked with arrows are ground

How to make a ground loop

From all of the above, it can be seen that not only convenience and peace of mind, but also the life of people depends on the reliability of grounding. Therefore, the manufacture of the contour must be taken extremely seriously. Do you know how to hold in your hands a shovel and a hacksaw for metal and are you confident in your abilities? Then get down to business! But before figuring out how to properly make grounding in a private house, it is necessary to decide the question of what to make it from and what structure to choose.

Choice of design

The main problem that needs to be solved in the manufacture of grounding is a good electrical contact of the circuit with the ground. It would seem that the simplest solution is to dig in a voluminous metal object.

If you have a couple of old but strong barrels at your disposal, a rear axle from a KAMAZ or something similar, then the option is quite feasible. You weld the metal bus to the object, dig in the object itself, and bring the bus to the surface. But, simple in appearance, this method has a lot of disadvantages:

1. The subject should be fairly voluminous and unpainted. Its cost, even at the price of scrap metal, can be much higher than the cost of high-quality material for the manufacture of a classic drive-in circuit.
2. To get high-quality grounding, the object must be buried at least 2 m, and if the soils are sandy, then by all 3 m.
3. Since the item is in damp earth, it will naturally rust. How long will the same barrel with a wall of 1.5-2 mm last? On the strength of a year or two. And then the circuit will simply fail, and you will find out about this after the fact - when you get under voltage. If you nevertheless decide to dig in something, then this something must be really "something", capable of not rusting for decades.

Much more reliable and durable grounding can be obtained using long rods driven into the ground to a certain depth and electrically connected to each other. The key factor here is the number of pins and their length. By design, these types of grounding are divided:

• linear;
• volumetric.

Linear grounding consists of a series of pins driven into the ground and connected in series. The volumetric type means several pins driven in a circle and connected into a ring.

Linear (left) and volumetric types of grounding loops

In principle, both types provide high-quality grounding of equipment, a small difference is only in reliability. If one of the jumpers in the linear grounding breaks down, a number of grounding pins are excluded from operation, which leads to an increase in the resistance of the grounding loop.

In this case, the electrical characteristics of the volumetric structure are practically not affected. Nevertheless, with well-made jumpers, the likelihood of such an accident is small, therefore, when choosing the type of grounding, it has meaning to be guided only by the expediency and convenience of manufacturing a particular design, depending on the specific conditions.

Material options

It is not worth saving on materials - after all, your safety depends on their correct choice. A corner from 40x40 and above is ideal as pins.. It is tough enough for clogging, and has a large surface area for minimal transient resistance. If you don't have a corner at your disposal, then a thick-walled water pipe or a pin with a diameter of at least 15-20 mm will do.

There is an opinion that fittings cannot be used as grounding rods - they supposedly quickly rust. This statement is absolutely groundless - the corrosion resistance of the reinforcement is no worse than the resistance of the same corner or pipe, and it is much easier to drive in the reinforcement than, say, a soft rod. So if you have fittings with a diameter of 16 mm and above, you can safely use it. In this case, the length of the pins must be at least 2 m, and their number depends on the type of grounding you have chosen, but at least three pieces.

An iron strip (tire) with a width of 15 and a thickness of 5 mm is ideal as jumpers. This section was chosen solely for reasons of durability, since even an eight-millimeter wire rod will withstand the emergency short-circuit current. It's just that it will rot faster and harder to cook. An ordinary corner or reinforcement of the corresponding section will also go for jumpers, but it will cost, of course, more. In any case, all materials should not have a dielectric coating - paints, mastics, etc.

Manufacturing process

If you have selected the right materials, you have a shovel, a welding machine, a sledgehammer and a hacksaw at your disposal, then you can start working. The whole process of making a contour can be reduced to the following basic operations:

1. Markup.
2. Digging a trench.
3. Driving in grounding rods.
4. The connection of the pins to each other with jumpers and the output of the grounding bus to the surface.
5. Backfilling of the trench.
6. Checking the quality of grounding.

Regardless of the circuit design you choose, you must use at least 3 pins spaced at least 1.5-2 m.If your personal plot is a continuous lawn, then it is most convenient to use a linear scheme, digging in the contour along the wall of the building or garden tracks.

Having marked the place for the pins, you can proceed to digging a shallow (20-30 cm) trench connecting the marking points. It makes no sense to dig deeper - the bus laid in the trench will play the role of jumpers, not grounding. Contrary to the opinion of "experts", it rusts in exactly the same way at any depth. The main task of the trench is to hide the tire so that people do not stumble over it.

Since there is a lot of free space near the house, the "triangle" scheme was chosen

Now the most important and difficult operation is driving in the grounding rods. To do this, their ends must be cut off at an angle of about 30 degrees. You can drive in with an ordinary sledgehammer, but some use an ordinary puncher for this purpose.

Grounding rods can be driven in with a sledgehammer or hammer drill

The pins are hammered to the full length, only the ends 10-20 cm long remain on the surface. Jumpers will be welded to them. After all the pins are clogged, they need to be connected together with a bus. For this, it is better to use welding - it is much more durable and more reliable than a bolted connection.

Welded joint (left) is less aesthetically pleasing, but much more reliable than bolted

Immediately weld the branch bus to the almost finished structure - the house circuit will be connected to it.

Discharge bus and the option of connecting a house circuit to it

It remains to paint over the welding spots with any paint or mastic, wait for it to dry and fill in the trench. If possible, it is advisable to do this with sand for better drainage - and the tire will last longer, and the ground around the pins will be more humid. If the sand is unacceptable for technical or aesthetic reasons, then you can use the earth - no big deal. Fall asleep, plant grass. Question. you decided how to make grounding in a private house, but the circuit must be checked.

Checking the electrical characteristics of the loop

Now you need to make sure that the loop is reliably connected to ground electrically and can act as an emergency ground. For a check, you can call power engineers with special equipment for a fee, but it is quite realistic to carry out quality tests and on our own.

To do this, you will need any powerful electrical appliance with a capacity of about 1 kW. An electric stove, iron, heater, etc. will do. You also need a voltage indicator (screwdriver indicator), a piece of wire and an AC voltmeter.

Using the pointer, find the phase in the outlet and measure the voltage between it and your ground. Write down the readings of the device. Now connect the device between phase and circuit. It should work fine. Repeat the measurement and compare with the readings obtained without load. If the voltage under load has dropped by no more than 10-15 V, then the ground loop can be considered working.

Grounding check circuit (a light bulb is conventionally shown as a load)

If the voltage drop is greater, repeat the measurement operation, but now, instead of the circuit, use the standard zero in the outlet. It also drops a lot - your wiring cannot cope with even a relatively small load and it's not about grounding. If there is no large drop, then you will have to add a few more ground rods to your loop and repeat the tests.