When talking about electricity, safety is paramount. Therefore, there are a series of standards and recommendations offered to professionals in this area. Among them, in particular, there is NBR 5410, which stipulates the appropriate conditions for the usual and safe operation of low voltage electrical installations, that is, up to 1.000 V in alternating voltage and 1.500 V in direct voltage.
NBR 5410, which is mainly applied to building and residential installations, is undergoing a review process. According to electrical engineer Paulo Barreto, from Barreto Engenharia, one of the changes in the new proposed text will be in the conductor selection part.
“Many ask whether there will be significant changes, as occurred with the lightning protection standard. We can say no. It will be a very smooth update without any major surprises”, said Barreto.
Among the main innovations, the engineer highlighted that this new standard applies to low voltage electrical installations on public roads, such as lighting posts, advertising totems, traffic lights, signaling systems, radars, cameras for various uses and the like.
“The standard will not cover the public distribution of concessionaires, but the use of this electrical energy on public roads. It is something that comes to bring more security, and then each of the agents must adapt to the next edition of NBR 5410”, highlighted the specialist.
For Benedito Arruda, from Tramontina Eletrik, there is no denying that the review must cover these situations. “This aspect needs to be covered so that the benefits that currently exist in electrical installations also reach public lighting”, he commented.
Eduardo Demonte, from WAGO Brasil, also highlighted the importance of including this measure in NBR 5410. “As the main Brazilian standard in relation to the safety of low voltage electrical installations, it is essential that it covers these situations on public roads”.
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Paulo Barreto also explained that a new subsection will be inserted that will help the designer remember some considerations that must be made when designing. “When sizing an electrical installation, the first thing to remember is to consider the parameters of the power supply. Some may think: I already do that. It’s just that now it’s more explicit.”
He also commented that the standard warns about the need to consider harmonics, which affects the calculation of the design current, in addition to the maximum impedance value that guarantees protection against short circuits.
About NBR 5410
The reactivation of the NBR 5410 study committee began in March 2012. For practically two years the committee sought to round out the rules and format to be conducted in the new standards review process.
The content discussion began in February 2014. “Since then, we have been focusing on NBR 5410 and the contributions we have received over time from professionals in the sector, the technical community and the most recent updates to IEC 60364 – which is the international standard of the International Electrotechnical Commission for electrical installations in buildings”, he concluded.
An answer
Good day.
Is it certain that you plan, in the new revision, to eliminate protection against indirect contacts with automatic disconnection of the power supply through fuses or thermomagnetics? Will it be mandatory with DR?