⚡️ FREE CLASS: How to Do a Complete Electrical Installation from Scratch, Easily, Even if You Are Not a Professional Electrician: ➽ https://engehall.com.br/aula?utm_cont... ⚡️ DOWNLOAD DIAGRAMS: https://eletr.co/vdl_030923 How to TRANSFORM a TT GROUNDING into TN-S? Electrical grounding is undoubtedly one of the subjects that generates the most discussions among professionals in our field, either because of the old information that many professionals still insist on "sharing" as current and true, such as the myth of the 10 ohm resistance, or because of the practical experience of some who end up believing that one type of grounding is better than another, such as TT grounding being better than TN grounding. In any case, these “discussions” are acceptable, since they end up generating more interest in this subject and thus, making electrical installations safer and safer. For today’s class, we will add a little spice to this discussion. We will show how to transform a TT grounding system into a TN-S grounding system. Now, let’s align our knowledge. What is electrical grounding? Electrical grounding is a safety measure whose function is to connect a piece of equipment to the ground in order to eliminate current leakage from the system. It protects users against accidental electric shocks caused by equipment failures. There are basically 3 types of grounding: the TN system with its variations TN-C, TN-S and TN-CS, the TT system and the IT system. In the TN system, the neutral of the utility company is directly grounded in rods close to the input standard, and the equipment masses are connected to this point through protective conductors. However, in the variation we are going to discuss today, which is the TN-S scheme, the neutral conductor and the protective conductor are distinct throughout the scheme. In the TT scheme, the neutral conductor of the utility company is directly grounded to rods close to the input standard, and the masses of the equipment are grounded with a specific rod, different from the rod used to ground the neutral, that is, they are independent busbars. Well, now that everyone is aligned with the knowledge, we will show you how to transform a TT grounding system into a TN-S grounding system. As we saw before, in both the TT and the TN-S schemes, the neutral conductor of the utility company is grounded to the input standard. This grounding is called functional grounding and serves to “balance” the currents that return through the neutral, due to the unbalance of the loads, so that they do not return to the utility company's electrical grid. In addition to this standard grounding, other rods are generally used to perform protective grounding, both for TT grounding and TN-S grounding. So, in theory, the basic structure of TT and TN-S grounding is practically identical. The difference lies in the equipotentialization of these rods, both for functional grounding and for the protective grounding rod. Equipotentialization seeks to ensure that all the masses and conductive elements of a building are as close as possible to the ground potential. And this equipotentialization can be done either inside the QDC, like the one we did at Leandro Torneiro's house, or in a specific box, like the one we did at the Galpão project. Therefore, to transform a TT grounding into a TN-S grounding, simply connect the neutral busbar to the ground busbar, just as we did at our headquarters project in Natal. For those who followed this live on the site, you can see that we joined all the groundings to a single ground bus and then connected this bus to another bus, called the Equipotentialization Bus, or BEP, which was also connected to the neutral bus of the panel. To make it easier to understand, see this diagram. On this side, we have the grounded input standard and from this standard, the grounded neutral of the utility company goes to the neutral bus of the QDC. On the other side, we have the grounding that goes to the ground bus of the QDC. In this way, this type of grounding is called TT, since the mass of the equipment will be connected directly to the ground bus. Now, when the Neutral bus is interconnected with the Ground bus, we are equipotentializing the ground and the neutral, making the grounding become TN-S. Remember, guys, when we have TT grounding, all the circuits of the QDC must be protected by the IDR. When the grounding is of the TN-S type, the use of the IDR is mandatory only in wet areas. Furthermore, by opting for the TN-S type grounding, it is not necessary to measure the grounding resistance, for this reason I prefer the TN-S grounding.