???? REGISTRATION LINK: https://ep.engehalleletrica.com.br/se... ⚡️ FREE CLASS: How to Do a Complete Electrical Installation from Scratch, Easily, Even if You Are Not a Professional Electrician: ➽ https://eletr.co/aula?utm_content=yt1... ------ ???? FAAALA ENGEHALL COMMUNITY ???? Join our community on WhatsApp to receive valuable tips and news in the electrical area, important information and much more. ???? ???? https://eletr.co/fala-eng?utm_content= ------ Did you like this video? ???? ✔️ Leave your comment and share with your friends ✔️ Follow our networks ➽ https://eletr.co/links - - - - - - - - - - - - - - - - - - - - - - - - - - - - - DPS must ALWAYS BE installed after the MAIN CIRCUIT BREAKER??? Well, today's video came up precisely in the comments of other videos, and I'll tell you in advance, it will be CONTROVERSIAL, many people will disagree, but we will try hard to explain everything! After all, does the DPS really have to ALWAYS BE installed after the QDC's MAIN CIRCUIT BREAKER or not, can I install it before the main one? Interesting question, right? We've reached another episode of our Pica o Pé no Pica Fio series! For those of you who just got here, I'll explain what's going on: “Pica o Pé no Pica Fio” is a series in which we try to show how to solve some problems that Zé Faísca and Pica Fio can't. And all of this is thanks to the stories of installations that went wrong sent by you for us to investigate and look for solutions, in addition to answering technical questions, which is the case of today's video. Well, let's get to the point: Today's class is based on a very interesting question... can I install the DPS before the main circuit breaker of my QDC or is it really mandatory for the DPS to be installed after the main circuit breaker? So, this is a technical question, right? And when we have questions about how to do an installation, where should we look for the answers? That's right, here at Engehall! Jokes aside, in addition to knowing our opinion of course, let's see what NBR5410, the electrician's holy bible, mentions about it, because without a doubt our opinion is based on what it does. Item 6.3.5.2.5 of NBR-5410 is the item that addresses DPS failure and protection against overcurrents. And what does this item mention? “The possibility of an internal failure, causing the DPS to short-circuit, imposes the need for an overcurrent protection device to eliminate such short-circuit”. Well, here we see an obligation: The DPS needs to be protected by a circuit breaker precisely so that in the event of an internal problem in the DPS, it does not cause problems in the QDC in the event of a failure in the DPS, such as an internal short circuit. In short, if the DPS fails, it cannot affect the installation. But here we need to go deeper: “What can cause problems in the DPS, André?” Well, my dear, the possible causes of problems in the DPS can be three main ones: 1 - In the event of a surge, the current of this surge is well above the capacity that the DPS supports, for example, a 20kA DPS, receiving a 60kA surge, okay, it is a sizing error, but it can happen. 2 - Using a DPS with the wrong voltage, for example, the network is single-phase 220V and there is a DPS of 175V, this is a simple thing, but I have seen installations like this. 3 - The varistor, which is the main part of the DPS, reaches the end of its useful life, this is less likely to cause a problem, but it is worth mentioning here. Well, to protect yourself against these failures, the standard logically recommends the best ways to install, there are 3 options for installing the DPS. Message given, let's talk about the correct ways to install DPS. In this first option, note that there is an exclusive protection circuit breaker for the DPS. In this case, if a problem occurs in the DPS, it will trip the circuit breaker and the installation will continue to work. In the second option, the DPS is protected by the installation's main circuit breaker. This type of installation is the most used by electricians, but here comes the detail: it can be either the QDC's general circuit breaker or the QM's general circuit breaker. But, it is precisely in this second option that the doubt in this video arose. Do you agree with me that the input standard circuit breaker is a general protection of the installation? That in the case of a short circuit, it can also act and protect the DPS? If I install the DPS before the QDC's general circuit breaker, the input standard circuit breaker will fulfill the DPS's protection role required by the standard! This is talking about simpler installations, ok, when we have more than 1 QDC in the same standard, the conversation changes, but it's silly!