Protective grounding: definition and varieties, installation reasons and actual design, safety

Life without electricity is hard to imagine today. People are so accustomed to electrical appliances that sometimes they completely forget about the dangers that are fraught with non-observance of electrical safety rules. For example, few people know how to properly organize and make reliable protective grounding. Determining the factors influencing the choice of protection and its organization can be an insurmountable task if you do not know the underlying principles.

Installation reasons

The fact that electric current can cause death of a person is known to any schoolchild. However, thousands of people are exposed to the risk of electric shock every year. Most often this happens for an elementary reason - non-observance of electrical safety rules. One of these rules is associated with reliable electrical grounding of devices and installations that are energized.

The very concept of electrical grounding means that the body of any electrical appliance must be connected to a grounding device. This is done in order to protect the person who touches the dangerous area in the event of an unforeseen voltage drop on the case.

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In this case, one of the protective principles is triggered:

1. Reducing the difference in capabilities to a safe value between the object that is grounded and the one that walks on the ground, if they are connected.
2. Discharge of electric current leakage and triggering of an emergency shutdown in case of contact of the carrier phase with a grounded object.

The presence of a voltage in the network that can harm human health already implies ensuring the safety of everyone who will use electrical appliances connected to this network. The primary concern is to properly and safely ground all possible points of contact. a person with sources of such danger.

With a properly organized protection system, the use of electricity becomes the safest. At the same time, the absence of such a system carries a high probability that sooner or later it will certainly lead to an accident. Therefore, the installation of electrical protection is not a whim of safety inspectors, but a real guarantee of the safe use of any device connected to this network.

Types of protection organization

There are two main types of electrical safety systems. Determining which one to choose for your needs is a very important factor in the correct organization of electrical safety. Considering each species separately helps to better understand its benefits and the real need for use.

Natural grounding

With artificial grounding, everything is extremely simple. This grounding is due to the fact that the structure or device is in direct connection with the ground. A typical type of such protection is the reinforced concrete foundation of the building.

One of the main advantages of this type of electrical protection is its efficiency, the absence of additional costs for equipment of protective equipment. Any metal enclosure in contact with the foundation is grounded. A significant disadvantage of this type is the inability to regulate the resistance, therefore it cannot be used to ensure the safety of electrical installations.

Artificial options

This type of electrical protection consists of a ground electrode and a conductor. Its quality is determined by the resistance indicator - the lower it is, the better the grounding. An earthing switch is a metal devicethat makes direct contact with the ground. It can be a simple iron or copper rod, as well as a complex structure specially made for this purpose.

The conductor serves as a connector between the grounding conductor and the electrical appliance. It can have an extra insert for auxiliary purposes. For example, the installation of an emergency shutdown or alarm.

There are several different artificial security systems. The main ones are:

1. Network with a dead-earthed neutral for installations (above 1 kV);
2. An isolated network or a grounded neutral through a register or an arc suppression reactor for installations (above 1kV);
3. Deafly grounded neutral for electrical installations (up to 1 kV);
4. Insulated neutral for installations (up to 1kV).

The choice of the protection system is determined even before the start of the construction of the facility and is determined by the regulatory requirements for the installed electrical equipment.

Security

When equipping electrical appliances and installations with proper protection, it is necessary to strictly follow the instructions of the normative documents. The main reason for the occurrence of an emergency and potentially dangerous situation is when a phase voltage on the body of the device creates a prerequisite for electric shock to everyone who comes into contact with him.

Any electrical appliance carries a latent danger, even when it is in good working order.. Some situations:

1. In the absence of a residual current device and housing grounding, even a serviceable device can pose a mortal danger to humans.
2. There is no RCD, but there is grounding. In this case, a dangerous situation may arise if there is a large leak from the earthing conductor.
3. The opposite situation: there is grounding, there is no RCD. In this case, when touched, a person receives a short-term blow before the network is disconnected, most often it is safe for life.
4. There is both grounding and an RCD. In case of any malfunction and dangerous situation, the presence of correct grounding ensures complete human safety.

When using electrical appliances, any person should not forget that not only his life, but also the life of his neighbors depends on the correct grounding device. By paying proper attention to ensuring this security, a person can safely enjoy the benefits of modern technology.