Effective ground loop

To protect people from harmful effects of electricity properties, special protective devices are used : RCDs, fuses, automatic devices (circuit breakers) and other safety measures. The most demanded human security system is the ground loop. This is a specific grounding device, the purpose of which is to connect with the "ground" of individual parts of electrical equipment. Or, in other words, connected to each other in the horizontal and vertical plane electrodes (diverters), placed under the surface of the soil at a certain depth.

The loop resistance is affected by:

• Type, structure and condition of the soil;
• Properties of electrodes;
• Depth of occurrence of electrodes;
• Number of electrodes.

Functionally, the grounding is divided into two types:

• Protective - designed to protect devices on electric traction from short circuits, people from harmful effects of dangerous currents arising at the time of failure.
• Working - maintains the required operability of the electrical installation through the earthing of its current-carrying parts.

The process of creating a path

Do not be intimidated by the question of how to make a ground loop, because to collect it in practice does not cause serious difficulties. In the role of divertors for grounding, metal corners with a side width of 45 or 60 mm, pipes of different diameters can approach. The grounding scheme in the form of a triangle is good in that, with a possible disruption of the connection of the divertor in one of the lines, the parallel line remains in operable condition.

Peaty soil, type loam and clay with a high degree of humidity is best suited for the installation of the contour. The worst type of soil is stony soils.

It is recommended to select a specific location in order to assemble the ground loop, the optimum area can be considered the zone near the switchgear. Earthing should be made of copper alloys or from black steel or galvanized without painting.

The shovel digs out a trench in the form of a triangle, the sides are 3 meters long, the depth is small - 0.5-0.8 meters. At the top of the triangle, a steel earthing rod 2.5-3 meters in length is clogged. The ends can be sharpened so that the metal can easily pass into the ground. Above the ground we leave a little, up to 20 cm, welded to them a horizontal steel strip leading to the power electric shield. Welding places will not be superfluous to treat with anti-corrosion paint or, for example, bitumen.

After installation, the ground loop is measured, at which the control level of its resistance is measured. This is done by an instrument called a megaohmmeter. In the future, repeated measurements are made at least once a year. For this, an artificial circuit with an electric current needs to be closed through the grounding device , then check the voltage drop in the circuit. Next to the main electrode, place an auxiliary electrode and connect it to the source. A measuring instrument near the zero potential fixes the magnitude of the voltage drop across the main electrode. In this way, the ground loop is measured more often than other methods.