For those who do not know, grounding is a special connection of all elements of the equipment, which even if not connected with electricity, but as a result of a breakdown of insulation can be energized, with the ground. This is necessary to ensure safety and protection against electric shock. In this article we will consider one of the types of this connection, which is called modular grounding.
What is the point?
What is grounding, we have decided. One of its types is modular grounding. This system is used both in residential and industrial enterprises. One of its advantages is the speed of installation. You can assemble and install such a system in a few hours. Moreover, this does not require specialized equipment or any technical skills.
Any digital or electrical equipment can fail, therefore, in order to avoid unpleasant consequences, they install deep modular grounding systems.
System benefits
Such a grounding system is popular at communication facilities, telecommunications, energy, etc. It is also used for grounding in problematic ground rocks and to great depths. In addition, the cost of installing the designs of these systems will be minimized.
Modular grounding systems have several advantages (judging by the reviews):
- Installation takes a short period of time, due to its convenience.
- Allows installation at any depth. When fastening vertical elements, the depth can reach 50 m.
- Lowest cost.
- The earthing switch is protected against corrosion because it consists of stainless steel and is copper-plated.
- No welding required.
- Does not take up much space. For installation, only 1 m 2 is needed.
- It does not require special equipment and a qualified specialist.
- It has a long service life (at least 30 years).
- The spreading resistance of the ground electrode system is independent of atmospheric conditions.
Shortcomings
Despite the large number of advantages, modular grounding also has several disadvantages.
First of all, it is the impossibility of using this system in rocky soil. When installing the structure in such soil, the system can either move the stone that has fallen in its path or bend around it. But this applies only to small stones. If the pin stumbles on a large and strong stone, then further installation of the system will be impossible.
Another disadvantage is the price category. Copper-bonded rods cost about 380-400 rubles per meter. Judging by the reviews, additional items of equipment for them are also not cheap. If we compare this system with standard grounding, then the price of a modular set will be lower than the price of drilling work, but higher than the price of ferrous metal. However, it is customary to compare not only the cost of materials, but also to take into account the durability of the design service and the time for which it pays off.
Types of grounding technologies
There are two main grounding technologies. This is a traditional and modular pin earthing.
For the device of the first type of grounding, pins are used that are driven vertically into the ground. Between themselves they are connected by steel strips. Then connect the ground loop to the distribution panel.
For the manufacture of traditional or standard grounding, ferrous metal is used. Stripes, pipes and a corner are made of it. To install this design at a depth of 3 m, three metal electrodes are driven in the form of a triangle. The interval between the electrodes should be 5 m. Then they are connected together using a metal strip and electric welding.
This grounding technology has a number of disadvantages. Among them, a large amount of land work, the need for welding and the susceptibility of metal to corrosion. Due to these imperfections, this technology has now faded into the background.
Ready Kits
Now in the markets there are a large number of ready-made devices for grounding. If you prefer to trust the factory settings, then you can easily pick up a ready-made kit of modular-pin grounding.
These ready-made kits include:
- grounding pin;
- threaded coupling;
- immersion tip;
- shock head;
- universal clamp;
- accessories for grounding installation (anticorrosion tape, sighting device, etc.)
Grounding pins, or they are also called rods, are made of high quality steel, and are coated with copper on top. The cross-section of the rods is about 14 mm, and the length reaches 1.5 m. These pins on both edges have a copper-plated thread. They are interconnected with brass threaded couplings.
Immersion tips and impact heads are provided for deepening the pins. They are screwed onto the threads of the pins. Tips are also subdivided, depending on the type of soil in which grounding is performed.
To connect the vertical and horizontal elements using universal clamps. All structural elements are treated with anti-corrosion drugs. Among these, a special paste is included.
Installation instructions
Installation of modular grounding begins with the preparation of the first pin. The starting tip is treated with conductive grease and put on the pin on one side. The coupling is also greased and put on the other side of the pin. Screw the guide head for the hammer into the coupling from the free side.
We hammer the pin into the ground with a jackhammer to the depth necessary for further work.
Remove the head from the pin without clutch. The remaining coupling is again treated with grease. We connect the following pin to the coupling. We take a new coupling and also process it with grease. Screw the head back into the new coupling. We connect everything with a pin already mounted in the ground.
Drive the pin into the ground again. Repeat the operation to obtain the desired penetration depth of the grounding electrodes.
When it comes to the last pin, you need to leave a part of it on the surface of the earth for its subsequent connection with the grounding conductor. We put a clamp on the electrode. We connect a grounding conductor to it. We wrap the clamp with waterproofing tape.
Mounting Features
When laying modular grounding, the pins are immersed in the ground with a blunter end, and the sharper one is used for fastening with the coupling.
Conductive grease is applied only to the inside of the couplings.
Collection of the structure before driving into the ground is done by hand. If the system loosens during the deepening process, it is necessary to tighten it, but again manually. Additional intervention of special tools is not necessary.
The jackhammer must be positioned so that a zero angle is maintained between the hammer and the pin, otherwise the structure may be damaged.
Depth of laying of conductors and sequence of work
For laying conductors, the optimum depth is 0.5-0.7 m. Above this depth, the surface soil layer is constantly exposed to various weather and human influences, which can disrupt the grounding system.
Carrying out the installation of grounding, it is initially necessary to dig a channel with a depth of 0.5-0.7 m. In it, install the grounding electrodes in accordance with the instructions described above.
Lay the connecting conductor in the channel and connect the electrodes to it using the supplied clamps. Then we connect the structure to the electrical panel and fill the channel with soil.