Electrical systems are everywhere in our daily lives, whether in our homes, workplaces or infrastructure. The safety and reliability of these systems are of paramount importance. Surge protection devices play a vital role in maintaining these two vital aspects. Its mission is to detect electrical anomalies, such as overloads, short circuits and overvoltages, and to take the necessary measures to protect equipment, circuits and people from these dangers.

The negative effect of electric current on electrical appliances.

The effect of negative electrical current on electrical equipment can be harmful. It can lead to degradation of components, electrochemical corrosion of connections, corrosion and unwanted electromagnetic disturbances. Therefore, it is necessary to take measures to prevent the effect of negative electrical current on electrical appliances to ensure their operation and longevity. Below we mention some of the basic electrical protection devices :

Disjoncteur circuit breaker

Electrical switches or circuit breakers are essential devices for detecting overloads and short circuits in electrical circuits. It is designed to automatically cut off the power when abnormal conditions are detected. Circuit breakers can be thermal, magnetic, or a mixture of the two, and come in a variety of sizes and capacities to suit different applications. They provide fast and reliable protection against electrical overloads.

Fusible Resistor

Fuses or fuses are important electrical protection devices. They work by cutting off the current when an overcurrent occurs. They consist of fusible filaments that melt when the current exceeds the rated capacity of the fuse, thus cutting off the power supply and protecting equipment and circuits from damage. Fuses are widely used in residential and industrial electrical installations and must be properly selected according to the current and load characteristics.

Types of fuses to protect against electrical current

There are different types of valves suitable for different applications and needs. Here are some of the most commonly used types of valves:

Fast-acting fuses : They react quickly in the event of a current surge and are used to protect electronic circuits and sensitive equipment.

Slow-blow fuses : These are designed to temporarily withstand higher overload currents before blowing, making them suitable for circuits with intermittent loads or high inrush currents.

Time Delay Fuses : Designed to provide additional protection in applications where temporary overcurrents are common, while preventing nuisance tripping.

Blade Fuses : Widely used in automotive and household applications, providing protection against overcurrent in the electrical system.

Thermal fuse : Operates in response to temperature rather than overcurrent, protecting equipment from overheating and thermal damage.

Relays

A protective relay is an electromechanical or electronic device used to monitor electrical parameters and detect abnormal variations. They are configured to react if pre-set limits are exceeded, triggering protective action. Protection relays play an important role in coordinating electrical protection, ensuring appropriate and rapid response to faults.

Current transformers Transformateurs de Courant

Current transformers are key components in electrical protection and measurement systems. They are used to convert high currents flowing in power lines into proportional low currents suitable for measurement and circuit protection. Current transformers provide accurate current signals, which can be used by protective relays to detect overloads and short circuits.

Electrical protection sensors

Sensors or sensors are devices used to monitor basic electrical quantities, such as currents, voltages, and frequencies, in real time. They are able to detect abnormal variations in these parameters and send alarm or trip signals to appropriate protection devices. Protection sensors play an important role in early detection of electrical problems and contribute to reducing risks.

Surge protection devices

Power surges can cause serious damage to sensitive electrical equipment. A surge protection device is used to disperse electrical current surges that could damage devices. These devices divert surge waves to the ground, protecting connected equipment.

Earthing system: basics of electrical protection

Grounding is a basic principle of electrical protection. It consists of connecting electrical components and installations to ground, thus creating a funnel for leakage currents and overloads. This reduces the risk of electric shock and prevents equipment damage. Various grounding methods and techniques are used, including:

Protective grounding (or safety ground)

This method consists of connecting exposed metal parts of electrical installations to ground. Items such as electrical boxes, distribution cabinets, appliances, and equipment are connected to a grounding conductor that is then bonded to a ground electrode, such as a copper rod or grounding plate, to the buried ground. This dissipates leakage currents and ensures personal safety by avoiding electric shock.

Functional grounding

This method is used to reduce electromagnetic interference and ensure proper operation of sensitive electrical equipment. It involves connecting non-conductive metal parts of equipment (such as displays, frames, and shields) to ground to eliminate static charges and stray currents.

Equipment grounding

Some specific equipment requires individual grounding to ensure proper operation and safety. These include generators, transformers, electric motors, and equipment sensitive to electromagnetic interference. Grounding this equipment helps dissipate unwanted currents and prevent damage.

Electrical connections

Electrical connections refer to the physical connections established between different electrical components, wires, or devices to allow the flow of electrical current. They are manufactured by securely connecting electrical conductors together, using appropriate methods such as bonding posts, connectors, bolts, terminal blocks, soldering, clamps, etc. Electrical connections are essential to creating a functional, reliable and safe electrical circuit, ensuring continuity of electrical current and avoiding misconnections or loss of signal.

Safety and quality standards

Electrical connections play an essential role in the efficient and safe transmission of electrical current. Proper connections ensure optimal conductivity, reduce the risk of overheating and reduce power loss. Safety and quality standards must be observed, such as proper tightening of terminals, use of appropriate connectors and proper insulation to ensure reliable electrical connections.

Electrical wiring tools : selection and use

To make safe electrical connections, various tools are used. They include :

• Plugs
• Keys
• source
• Plug
• Wires
• pliers
• Screwdrivers

Each tool has its own function and is specifically designed for specific electrical connections. Choosing  the right tools is crucial to ensuring correct and reliable electrical connections.

10 tips to prevent electricity risks

1)  Do not touch live electrical parts or exposed wires without proper protection.

2)  Disconnect electrical appliances from power sources before performing any maintenance work or connecting/disconnecting wires.

3)  Ensure that all appliances, cords and plugs comply with proper electrical standards.

4)  Handle electrical wires and plugs with caution, and do not pull them forcefully or tamper with them improperly.

5)  Avoid touching metal objects with wet hands or when there is an electrical leak, as there could be a risk of electric shock.

6)  Do not operate electrical appliances in a humid place or in the presence of water, as the risk of exposure to electric shock increases.

7)  Avoid performing electrical appliance repair work without the necessary experience, and rely on qualified maintenance technicians.

8)  Use appropriate protective electrical equipment such as insulating gloves and goggles when performing maintenance work or connecting/disconnecting electrical wires.

9)  Stay away from exposed electrical cables in public places or areas surrounding buildings, as they can cause electric shocks.

10)  Raising awareness and teaching individuals about the basics of electrical safety and the correct procedures for dealing with electricity.