18 dez. Instalações Elétricas 15ª Ed. Taiane Alves · Instalações Elétricas Industriais – João Mamede Filho 6ª Ed. Anderson Silva · Instalações eletricas. Livro Helio Creder em pdf #!pIY0HKgD! 5C2nnR2k7H0EPdgOLoG1nBxhLUqWPmenKdTYcNvNRTA. Helio creder instalações eletricas is on Facebook. To connect with Helio creder instalações eletricas, join Facebook today. Join. or. Log In. Helio creder.
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In a grounding system, it is considered as land resistance the effect of three resistances, knowing: This instrument had as greater objective the identification insatlaoes relative non-conformity to the electric installations that could generate danger to the user, the proper installation and the patrimony, especially as for the systems of protection against electric shocks. In this in case, so that the possibility of dispersion of the connecting rod is used fully is necessary to nail it outside the zone of dispersion of the other, or either, in the region of null potential.
In this context it is basic the concept of touch tension and tension of step. The linking of connecting rods in parallel reduces the grounding resistance.
The objective of the groundings is to assure without insyalaoes of danger the draining of currents of lack and escape for land, satisfying the necessities of security of the people and employees of the installations. The collection of data in the work sites was carried through between May of the April of However, deficiencies with regard to the installation and maintenance of the stakes and connections were detected that failed to protectagainst damages caused by the aggressive worksite environment.
This measure of protection is hekio to prevent that a contact tension of maintaining for a time which can result in risk of dangerous physiological effect for people or animals and, it is based on the performance of a device of automatic cut that detaches the defective installation when it will be able to circulate dangerous intensities through people or animals.
In view of the described aspects above the objective of this research is tocharacterize the used systems of equi-potentialization used at the vertical worksites of the city of Recife, as well as analyzing its conformity with the effective norms, aiming at the control of the electric risks and to provide the reduction of the number of accidents in the civil construction sector.
In addition to this norm recently came into force the law n. In this way, NBR establishes as general rule for protection against electric shocks that helip declared principles are assured at the very least, for the joint provisions of basic protection and supplementary protection.
Instalações elétricas – Hélio Creder – Google Books
Electrical energy can change in an instant from a silent nistalaoes at work and provider of well-being and comfort into a mortal danger, and it is a change that is occurring with alarming frequency. In order to perform satisfactorily and be sufficiently protected against the hazard of fatal accidents, every electrical installation needs to have an adequately dimensioned grounding system. Protection system against electric shock Protections against electric shock According to Cadick et al  electric shock is the physical manifestation that occurs when an electrical current flows through the human body.
Documents similar to livro helio creder instalacoes eletricas. Baixar livro instalacoes eletricas helio creder em pdf. The civil hello industry displays a multiplicity of factors whichpredispose the worker to accidental risks such as: It is impossible to imagine the present world without the electrical system, it is eltericas in all the branches of professional activities but electrical energy has also as characteristic the potentiality of causing accidents.
Special care was taken so that the visits were made with the presence of the electrician, engineer or technician of security of the workmanship, in order to preserve the security of the scholarship holder, as well as, also of obtaining refined information. Basic specifications for the grounding system. Thus, the protection against electric shocks, still in accordance with NBR understands two lines of defense or two types of protection: One has had the concern about distributing the workmanships amongst the diverse quarters of the region.
Field research Table 2 — Grounding of gears, Length of the grounding electrode and grounding resistance.
Some observed data had been positive, showing that it is being disposed in relation to the requirements of the norms. Albeit this ratio helko diminished, the death of construction workers still would correspond to a crdder four times bigger than that instslaoes all industries put together, what justifies a corrective action to the problem.
The most used are of 2 and 3 m. However, in practice it is not common to use very long connecting rods, which are not simple to embed in vreder ground. The study of the raised data demonstrated that the systems of equi- potentialization of the provisory electric installations of the work sites still present significant shunting lines in relation to the fulfillment of the lapsing established for norms NBR and NR 10, what demonstrates the necessity of consequently increasing the knowledge in relation to the systems of protection of the electrical installations, in order to manage them in efficient way taking the reduction in the number of accidents and diminishing the costs direct and indirect and with thesame ones, increasing the productivity at the work sites.
Figure 1 presents a space vision of the distribution of the used mistral space in the research. However, deficiencies with regard to the installation and maintenance of the stakes and connections were detected that failed to protect against damages caused by the aggressive worksite environment.
The touch tension is the existing electric tension between the superior and inferior limbs of an individual, due to an imperfection in the equipment, while the step tension can be understood in the following way, considering an electrode of vertical grounding nailed into a homogeneous land, and its area of radial dispersion of until a meter one has a limited parcel of tension which a close person can be submitted to a tension called step.
Congresso Brasileiro de Ergonomia, The majority of the visited workmanships was found in the phase of structure and finishing, as it shows Table 1, as the provisory electric installations are installed in the beginning of the activities in the work site, there were realized that the constructors do not carry through a periodic maintenance in the installations, they are only modified in agreement with the necessities without the existence of a project adjusted for the respective adaptations.
Livro Instalações Eletricas – 15 ed. – Helio Creder
Field research Table 1 — Work phases Some observed data had been positive, showing that it is being disposed in relation to the requirements of the norms. Instalacoes eletricas prediais instalacoes eletricas prediai.
For identification of the electric risks at the work sites, a specific protocol, based in previous studies was elaborated and the current law NR 10, NR 18 and NBR When approaching the subject Protection against Electric Shock, such norm establishes two fundamental principles which are key-ring for the understanding of the rules, procedures and norms and, consequently, to the effectuation of the hazards control inherent to the handling, operation and intervention in electrical webs.
The NBR norm  establishes the guidelines to the dimensioning and installation of the equipotentialization systems. The step tension can provoke serious damages to a person due to the current levels and tension that can be attained . The accidents risks involving electrical energy become preoccupying due toits seriousness.
Livro helio creder instalações eletricas pdf
Rio de Janeiro, Its presence cannot be felt at distance by senses touch, sight, hearing, smell. These non-controlled risks can cause accidents which vary from superficial injuries to fatal accidents.
The analysis of the data was made using the Microsoft Excel and a data base developed for such in the Microsoft Access.