In any electrical installation it is vital to take into account the importance of grounding. There are mainly two types of protections that depend on grounding in a basic way for their correct operation. These are protection against transient overvoltage (protection of equipment), and differential protection against indirect contacts (protection of people). The effects of transient overvoltage’s on an installation are avoided by transient surge protectors (SPD). These act by diverting the energy of the overvoltage to the ground, thus preventing damage to electrical and electronic equipment.
How does grounding work?
It is connected and distributed throughout the installation by means of a cable, which is usually green and yellow, which must accompany the electrical voltage cables in all its derivations. Any short circuit or moisture, inside the electrical appliance , that reaches its metal parts with connection to the ground, will seek the way to a lower potential, finding a low resistive path in it , avoiding passing to the ground through the body of the user who may accidentally touch the device, since our skin will offer a greater resistance than our grounding rod.
Total protection against electric shock is achieved with the differential switch, which causes the electrical connections to open when it detects that there is a tap to earth inside the electrical installation.
Because it is important?
Due to safety regulations, the installation of grounding is a requirement in all electrical installations to ensure the discharges that may occur due to electrical failures. In the same way, the periodic measurement of the resistivity values of the system, verifying its status and maintenance for its correct operation. The grounding not only provides security for people but also to equipment and machines. It avoids the possibility of suffering damage from insulation defects such as currents produced by atmospheric discharges (lightning).
The earthing systems must be periodically verified, since over time the humidity of the ground, the salts that compose it and the variations in temperature, deteriorate and degrade the earthing electrodes. This causes an increase in the connection resistance, compared to the values obtained in the initial measurements.
What is recommended?
It is advisable to check and check all connections and grounding devices at least once a year. In this way, when there is an increase in resistance in the system, the necessary corrections are taken. The measurements must be carried out by professionals who must report the status of the installation and its parameters through a Grounding Measurement Protocol, with the corresponding approved instrument. The Ground Tester can measure ground loop resistances using just clamps, making it an advanced utility tool.