Summary of Clase 2 bt

00:00:00 - 00:20:00

The YouTube video titled "Clase 2 bt" focuses on the applications, regulations, and practical uses of low voltage cables. The video explains the importance of selecting the right cable based on factors such as the location of the installation, whether it is a photovoltaic installation, a residential building, or a commercial center. The video also highlights the importance of using cables that meet fire safety standards, such as Afumex Class cables , especially in buildings where fire safety is crucial. The video discusses different types of cables, including flexible cables and those with PVC insulation, based on their fire safety properties. It also highlights the importance of installing cables that meet regulatory requirements for specific applications, such as motor power supply with frequency converters. The video discusses the issue of harmonics in interconnections and how they can elevate the frequency, causing the skin effect to occur. The video emphasizes the importance of using the right cable to avoid impedance matching and prevent the loss of desired currents and erosion on the motor's working surface. Additionally, the video explains the general method for calculating the cable's section based on the applicable regulations and the specific requirements of the installation.

• 00:00:00 In this section of the course on low voltage cables, the focus is on the applications and regulations for these cables. The choice of cable depends on factors such as the location of the installation, whether it is a photovoltaic installation, a residential building, or a commercial center. The regulations specify the use of certain types of cables for different scenarios, including public buildings and connection installations. An example is given of a residential building where the cable installation starts where the company's property ends and ends at the general control and protection panel. The regulations prescribe the use of Azumex class cables for public buildings and connection installations. Different types of cables, such as flexible cables and those with PVC insulation, are also discussed based on their fire safety properties. The importance of installing cables that meet fire safety standards, such as Afumex Class cables, is highlighted, especially in buildings where fire safety is crucial. Other types of cables are mentioned for specific purposes, such as RVK cables for installations where fire safety is not a significant concern. Overall, the regulations and requirements dictate which cables are suitable for different types of installations.
• 00:05:00 In this section, the video discusses different types of cables and their practical uses. For example, it mentions that cables with a voltage of 500 volts are commonly used for domestic extensions and reels, while cables with a blue cover are suitable for high areas or where additional mechanical protection is needed. The video also explains that cables with a screen or shielding are used to prevent electromagnetic interference, and that cables with a rubber cover are more durable and resistant to various elements such as greases, oils, and moisture. Additionally, it mentions specialized cables for temporary installations, mobile services, and low voltage applications. Finally, it highlights the advantages of using specific cables for motor power supply with frequency converters, such as the Retenax C Pro Marinet cable.
• 00:10:00 In this section, the speaker discusses the issue of harmonics in interconnections and how they can elevate the frequency, causing the skin effect to occur. They emphasize the importance of using the right cable to avoid impedance mismatch and prevent the loss of desired currents and erosion on the motor's working surface. They also mention different types of cables for photovoltaic installations, including ones with copper or aluminum corrugated sheathing, steel-reinforced cables for rodent protection, and special cables for communication purposes. The speaker highlights the importance of choosing the right type of cable to ensure longevity and performance in various applications, including pumps, fire alarms, wind turbines, petrochemical industry, cranes, mining, railways, ships, and solar installations. Finally, they explain the general method for calculating the cable's section based on the applicable regulations and the specific requirements of the installation.
• 00:15:00 In this section, the speaker discusses the three criteria for calculating the installation of cables: allowable current, voltage drop, and short-circuit current. The aim is to ensure that the cable does not overheat, that the voltage at the receiving end is not too low, and that the cable remains intact in the event of a short circuit. These criteria must be calculated, and the cable section that is obtained must be the largest among the three. The speaker also mentions the importance of considering other factors such as ecology and economy. Additionally, the speaker presents an example of calculating the cable section for a supermarket refrigeration system, taking into account the power, supply voltage, power factor, and cable length. The video emphasizes the importance of using the correct cable type for the specific installation system, and also mentions the need for correction factors to account for factors such as cable grouping.
• 00:20:00 In this section, the speaker discusses the concept of grouping and the correction factor for four circuits within a single tube or conduit. The correction factor is determined to be 0.7, which is then used to calculate the current-carrying capacity. The section size is found to be 4 millimeters based on the allowable current. Next, the speaker explains the criteria for voltage drop and determines that a maximum voltage drop of 5% is acceptable. Using the formulas provided, the speaker calculates the section size for the copper conductor as 6 millimeters. Finally, the speaker mentions that while short circuit criteria should be considered, it is not the dominant factor in low voltage applications.