What is it?

An electric current whose direction and value change periodically. It is the form of electricity commonly used in residential, commercial, and industrial networks.

What is it used for?

It allows for the efficient transmission and distribution of electrical energy and powers most installations connected to the grid.

Expert tip

When reading an equipment nameplate, look for the AC indication and also verify the nominal voltage and frequency.

What is it?

A proximity sensor that detects changes in capacitance and can recognize both metallic and non-metallic materials, depending on the application.

What is it used for?

It is used to detect the presence or level of products such as plastics, grains, liquids, powders, and other materials.

Expert tip

Sensitivity can be affected by humidity, product accumulation, and container material; correct adjustment is key to avoiding false detections.

What is it?

An electromechanical device designed to frequently connect and disconnect electrical loads using a control signal.

What is it used for?

It is used to control motors, resistors, lighting, and other loads from manual or automatic systems.

Expert tip

Select the contactor based on current, voltage, load type, and utilization category; the nominal current alone does not describe the entire application.

What is it?

An electric current that flows in a single direction. It is common in batteries, electronics, control systems, and solar energy.

What is it used for?

It is used to power electronic devices, automation circuits, and energy storage systems.

Expert tip

In direct current, polarity matters. Always respect the positive and negative terminals indicated by the manufacturer.

What is it?

A switching device used to isolate a part of the installation electrically in a visible or secure manner.

What is it for?

It allows a circuit to be taken out of service for maintenance, inspection, or intervention tasks.

Expert tip

Not all disconnectors are designed to interrupt load current. Always verify the utilization category and the manufacturer's specifications.

What is it?

The flow of electric charge that circulates through a conductor. It is measured in amperes (A).

What is it used for?

It is one of the basic variables for sizing conductors, protections, panels, and electrical equipment.

Expert tip

A current higher than expected can cause heating. The circuit design must take into account the load and the actual conditions of use.

What is it?

A set of one or more insulated conductors designed to carry electrical power or signals between different points of an installation.

What is it used for?

It connects equipment, panels, and circuits, and its selection directly influences the safety and performance of the installation.

Expert tip

The cross-section is not defined by current alone: length, voltage drop, temperature, installation method, and insulation type also play a role.

What is it?

A situation in which a circuit conducts more current than intended for a given period of time, without necessarily becoming a short circuit.

What is its impact?

It can overheat conductors and equipment, reduce their lifespan, and cause failures if adequate protection is not in place.

Expert tip

If a protection device trips repeatedly due to overload, it is advisable to check the connected load and the circuit sizing rather than increasing the breaker rating without analysis.

What is it?

The enclosure where the protection, maneuvering, control, and distribution devices of an electrical installation are housed and organized.

What is it used for?

It centralizes circuits and protections, facilitates operation, and allows for the organized distribution of power to different loads.

Expert tip

A good panel must account for space, ventilation, identification, degree of protection, accessibility, and spare capacity for future expansions.

What is it?

The amount of electrical energy that a piece of equipment consumes, delivers, or transforms per unit of time. It is usually expressed in watts (W) or kilowatts (kW).

What is it used for?

It is used to estimate consumption, size installations, and compare the electrical demand of different equipment.

Expert tip

In alternating current loads, the useful power does not always equal voltage multiplied by current: the power factor can also play a role.

What is it?

A protective device containing a conductive element designed to melt when the current exceeds a specific value.

What is it for?

It interrupts the circuit during overcurrents and helps protect cables and equipment from major damage.

Expert Tip

When a fuse operates, it must be replaced with another of the same type and specifications. Never replace it with an improvised element.

What is it?

The system that connects specific parts of an installation to the ground using conductors and electrodes designed for that purpose.

What is it for?

It helps conduct fault currents and allows protective devices to operate correctly, reducing risks to people and equipment.

Expert tip

Grounding must be verified as a complete system: continuity, connections, protective conductor, and ground resistance are all parts of the same assembly.

What is it?

A human-machine interface that allows for the visualization of process information and the transmission of commands to the control system, typically via a screen.

What is it used for?

It enables operators and technicians to monitor variables, alarms, statuses, and parameters of a machine or facility.

Expert tip

A good HMI should prioritize clear and actionable information: too much data on the screen can hinder operation instead of helping.

What is it?

A proximity sensor that detects metallic objects without the need for physical contact, using an electromagnetic field.

What is it used for?

It is used to detect the position, presence, or passage of metal parts in machinery and industrial processes.

Expert tip

Verify the sensing distance, output type, power supply, switching frequency, and target object material before making your selection.

What is it?

A rating that indicates the protection level of an enclosure against the ingress of solid objects and water. It is expressed by the letters IP followed by two digits.

What is it for?

It helps in selecting suitable enclosures, boxes, and equipment for the environment where they will be installed.

Expert tip

A higher IP rating does not always mean it is the best option: choose the necessary grade based on dust, water, cleaning, weathering, and actual conditions of the site.

What is it?

A protection and switching device designed especially for motor circuits. It combines overload and short-circuit protection in a single unit.

What is it used for?

It simplifies motor protection and allows for connection and disconnection switching operations in many applications.

Expert tip

Select the adjustment range so that it includes the actual rated current of the motor, and verify the coordination with the rest of the starter components.

What is it?

A programmable logic controller: an industrial device that receives signals, executes programmed logic, and controls outputs to machines and processes.

What is it used for?

It is the brain of many automation systems, allowing the coordination of sensors, actuators, motors, and operating sequences.

Expert Tip

When choosing one, consider the quantity and type of inputs and outputs, communications, expansion capacity, installation environment, and ecosystem support.

What is it?

A device that converts available electrical energy into a voltage and current suitable for powering other devices, for example, from 220 V AC to 24 V DC.

What is its purpose?

It is essential for providing stable power to PLCs, sensors, relays, HMIs, and other control components.

Expert tip

Size the power supply with sufficient margin and check inrush current, temperature, efficiency, and the need for redundancy when the system is critical.

What is it?

A protective device that disconnects the current when it detects an electrical leakage to the ground. It is primarily designed to reduce the risk of electrical shocks to people.

What is its purpose?

It helps protect people from indirect contact and insulation faults in an installation.

Expert tip

It does not replace the thermomagnetic circuit breaker. Test it periodically using the TEST button, and have the installation inspected if it does not trip correctly.

What is it?

A fault in which two points with different voltages are connected by a very low impedance, generating a very high current in a very short time.

What is its purpose?

Understanding it is key because it can damage equipment, cables, and panels, in addition to creating a fire hazard.

Expert tip

Protective devices must have an adequate breaking capacity for the potential short-circuit current at the point where they are installed.

What is it?

An alternating current system that uses a single phase to power loads. It is common in homes, businesses, and lower-power equipment.

What is its purpose?

It is a simple form of electrical distribution for consumers that do not require a three-phase power supply.

Expert tip

Before choosing equipment, confirm whether the available power supply is single-phase and what its nominal voltage is.

What is it?

An electronic device that reduces the voltage applied to the motor during startup and, in some cases, during shutdown.

What is its purpose?

It reduces current peaks and the mechanical stress associated with the direct starting of motors.

Expert tip

It is ideal when you need a progressive start but do not need to control the speed during operation; for that, a variable frequency drive is typically used.

What is it?

A device that limits transient overvoltages, such as those caused by indirect atmospheric discharges or grid operations.

What is it for?

It helps protect electronic and electrical equipment against very short-duration voltage spikes.

Expert tip

Overvoltage protection is designed in stages and must be coordinated with the grounding system and the characteristics of the installation.

What is it?

A component used to connect and organize electrical conductors through identified and accessible connection points.

What is it for?

It facilitates wiring, maintenance, testing, and modifications within panels and equipment.

Expert tip

Choose the terminal block according to the conductor cross-section, current, voltage, and the type of connection required; a correct termination is as important as the component itself.

What is it?

A protective device that detects prolonged overloads in motors based on the thermal effect of the current.

What is it for?

It helps prevent damage from overload, rotor blockage, or abnormal motor operating conditions.

Expert tip

The setting must correspond to the motor's nominal current and the operating conditions indicated on its nameplate and technical documentation.

What is it?

An automatic circuit breaker that cuts off the current when it detects a prolonged overload or a short circuit.

What is it for?

It protects cables, installations, and equipment against currents higher than those the circuit can safely handle.

Expert tip

The rating must be selected based on the conductor cross-section and the installation conditions, not solely on the power of the connected equipment.

What is it?

An alternating current system consisting of three phases that are out of phase with each other. It is widely used in industry and in higher power equipment.

What is it for?

It allows for the efficient distribution of power and feeds motors, machinery, and large electrical consumers.

Expert tip

In three-phase motors, in addition to the voltage, it is important to verify the phase sequence when the direction of rotation is relevant.

What is it?

An uninterruptible power supply that provides temporary power when the utility grid fails and, depending on the model, also conditions the quality of the power supply.

What is it used for?

It keeps critical equipment running during short outages or provides enough time to perform a safe shutdown.

Expert tip

Do not size it based on watts alone: also verify VA, required runtime, load type, and the appropriate UPS technology for the application.

What is it?

An electronic device that modifies the frequency and voltage supplied to an alternating current motor to control its speed and operation.

What is it used for?

It allows for process regulation, reduces mechanical stress, and, in certain applications, decreases energy consumption.

Expert tip

The selection must consider power, current, load type, environmental conditions, and requirements for braking, control, and communications.

What is it?

The electrical potential difference between two points. It is the magnitude that drives the movement of current and is measured in volts (V).

What is it for?

It allows knowing at what voltage level a piece of equipment or an installation must operate in order to function correctly.

Expert tip

Before connecting any equipment, always verify that its nominal voltage is compatible with the available network.