{"id":82705,"date":"2026-09-23T17:16:56","date_gmt":"2026-09-23T20:16:56","guid":{"rendered":"https:\/\/a3aengenharia.com\/?post_type=articles&#038;p=82705"},"modified":"2026-09-23T17:16:56","modified_gmt":"2026-09-23T20:16:56","slug":"nbr-14039-medium-voltage-electrical-installations-requirements-application-2","status":"publish","type":"articles","link":"https:\/\/a3aengenharia.com\/en-us\/content\/technical-articles\/nbr-14039-medium-voltage-electrical-installations-requirements-application-2\/","title":{"rendered":"NBR 14039: Medium-Voltage Electrical Installations, Requirements, and Application"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">The <strong>ABNT NBR 14039:2021<\/strong> is the Brazilian standard that establishes requirements for the design and execution of medium-voltage electrical installations with nominal voltage from <strong>1.0 kV to 36.2 kV<\/strong>, at power frequency. In practice, it organizes minimum criteria for safety, continuity of service, protection, selection and installation of components, grounding, verification, maintenance, operation, and substation configuration within this scope.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The standard applies both to installations supplied by the utility network and to installations supplied by their own medium-voltage source. It also covers new installations, renovations, and temporary or permanent installations. This means NBR 14039 should not be consulted only when building a new primary substation: it also guides load expansions, transformer replacement, protection modernization, feeder reconfiguration, substation refurbishment, and interventions that change the technical conditions of the installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Another essential point is that compliance with NBR 14039 does not eliminate the need to observe other requirements. The installation itself may be subject to utility standards, ANEEL rules, NR-10, equipment-specific standards, protection and short-circuit criteria, and other applicable technical documents. Therefore, medium-voltage compliance results from <strong>coordinated engineering<\/strong>, not from reading a single standard in isolation.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">What Is the Scope of NBR 14039<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The scope of NBR 14039 begins with the voltage range: medium-voltage installations from 1.0 kV to 36.2 kV. Within this range, the standard addresses electrical infrastructure used for generation, distribution, and utilization of electrical energy, including utility-supplied installations and installations with on-site generation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This definition is important because an industrial plant, large building, hospital, data center, shopping center, logistics center, or infrastructure project may simultaneously include low- and medium-voltage sections. In such cases, the standards boundary must be understood in the design: <a href=\"\/conteudo\/artigos-tecnicos\/nbr-5410\/\">NBR 5410 for low-voltage installations<\/a> and NBR 14039 apply to different domains, even though both may be present within the same electrical architecture.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A <a href=\"\/conteudo\/artigos-tecnicos\/elementos-de-uma-subestacao\/\">electrical substation<\/a> is a good example of this interface. The medium-voltage side, switching and protection devices, MV cables, grounding, and the substation requirements themselves fall within NBR 14039. After transformation, the low-voltage circuits become subject to the criteria applicable to that voltage level.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The standard also makes clear that its requirements represent minimum conditions. In installations subject to aggressive environments, explosive atmospheres, specific industrial processes, high criticality, on-site generation, or particular utility requirements, other standards and specifications may impose additional requirements.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">How NBR 14039 Structures the Installation Lifecycle<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The structure of the standard helps explain why its application goes beyond sizing a primary substation. It first defines fundamental principles and general characteristics of the installation; then addresses protective measures, selection and installation of components, final verification, maintenance, operation, and specific substation requirements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This sequence creates an engineering logic:<\/p>\n\n\n\n<ol class=\"wp-block-list\"><li>define what the installation must supply and under what conditions;<\/li><li>identify external influences, risks, and system characteristics;<\/li><li>select protective measures;<\/li><li>size and specify components;<\/li><li>execute according to the design;<\/li><li>verify by inspection and testing;<\/li><li>maintain the installation within the intended conditions;<\/li><li>control changes that may invalidate the original assumptions.<\/li><\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">The key point is that each stage depends on the previous one. A relay cannot be correctly set if the short-circuit level is unknown. A cable cannot be selected solely from load current if installation method, temperature, grouping, and fault current are ignored. A substation cannot be accepted if the design, test results, and as-installed condition cannot be correlated.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This chain also helps organize audits and upgrades. Instead of asking only \u201cdoes the installation comply with the standard?\u201d, the assessment should ask <strong>which assumptions were defined, which controls were designed, what evidence demonstrates execution, and which current conditions may have changed performance<\/strong>.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">NBR 14039, NR-10, ANEEL, and Utility Standards Are Not the Same<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A recurring error is to treat NBR 14039 as if it were the only document required for full compliance of a medium-voltage installation. It is not.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">NBR 14039 is a <strong>technical installation standard<\/strong>. <strong>NR-10 is a regulatory standard for occupational safety and health in electrical work<\/strong>. <strong>ANEEL establishes regulatory rules for electricity distribution services<\/strong>, while the local utility has connection, metering, protection, and supply standards that must be met at the grid interface.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The practical consequence is that a design may be technically coherent in one aspect and still have shortcomings in another. A primary substation, for example, may have equipment suitable for the nominal voltage but protection settings incompatible with utility coordination requirements. Likewise, an installation built according to design may have insufficient documentation, procedures, or operating conditions from an occupational-safety perspective.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"\/conteudo\/guias-tecnicos\/guia-completo-nr-10-seguranca-instalacoes-eletricas\/\">NR-10 compliance<\/a> should therefore be treated as a complementary layer. A new NR-10 text was published in 2026, with general effectiveness scheduled for June 1, 2027, reinforcing the need to control the applicable version during long-term designs and compliance programs.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">At the utility interface, the design should verify, among other aspects, the point of delivery, metering requirements, short-circuit levels, protection philosophy, interrupting capacity, selectivity, and protection-function settings. NBR 14039 establishes the need to coordinate with these external conditions, but the design must use the actual data of the system to which it will be connected.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">What Data Must Be Available before Designing a Medium-Voltage Installation<\/h2>\n\n\n\n<div class=\"wp-block-a3a-destaque\">\n<p class=\"wp-block-paragraph\">When the project does not yet have sufficiently defined architecture, transformation capacity, protection philosophy, and utility interfaces, compliance must be built into the design rather than corrected after installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"\/servicos\/planejamento\/projeto-subestacao-media-tensao-cabine-primaria\/\">Medium-Voltage Substation and Primary Substation Design<\/a><\/p>\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\">Before sizing cables, selecting switchgear cubicles, or specifying transformers, the supply and utilization characteristics of the installation need to be defined.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Supply capacity should not be treated as a simple sum of nameplate ratings. The assessment needs to consider expected loads, simultaneity, operating regime, motor starting, future expansion, on-site generation, critical loads, power quality, and distribution architecture. The <a href=\"\/conteudo\/artigos-tecnicos\/quadro-cargas-eletricas\/\">electrical load schedule<\/a> and demand studies are inputs to a broader capacity decision.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For medium voltage, the main input data typically include:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>nominal supply voltage and permissible variation levels;<\/li><li>installed power and expected demand;<\/li><li>number, rating, and impedance of transformers;<\/li><li>available short-circuit level at the point of connection;<\/li><li>grounding arrangement;<\/li><li>cable lengths, installation methods, and characteristics;<\/li><li>load profile, including motors and nonlinear loads;<\/li><li>need for redundancy or continuity of service;<\/li><li>environmental conditions and external influences;<\/li><li>utility metering and protection requirements;<\/li><li>planned future expansions.<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Missing these data often reappears later as oversizing, lack of expansion capacity, improvised settings, inadequate protection, or premature equipment replacement.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For existing installations, the starting point is often different: before design begins, it may be necessary to perform an <a href=\"\/servicos\/levantamento-e-diagnostico\/levantamento-cadastral-edificacoes-instalacoes-infraestruturas\/\">as-built survey of buildings, installations, and infrastructure<\/a> to reconstruct the actual field condition.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">External Influences: the Right Equipment Depends on the Right Environment<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">NBR 14039 does not treat the installation as though all components operated in an ideal environment. Temperature, humidity, altitude, presence of water, dust, corrosive substances, mechanical stresses, fauna, vegetation, construction characteristics, and conditions of use can affect component selection and installation methods.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This approach is important because many problems attributed to \u201cequipment\u201d begin with incompatibility with the environment. A cubicle installed in an aggressive atmosphere, a cable termination exposed to recurring moisture, or a component with insufficient ingress protection can deteriorate rapidly even if its nominal electrical ratings are adequate.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">External influences should be assessed before specification. In an industrial substation, for example, nearby processes may introduce conductive dust, mist, contaminants, or temperatures different from those found in a commercial building. Outdoor installations also involve solar radiation, rain, condensation, and environmental stresses.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This issue also affects maintenance. Components exposed to more severe conditions may require inspections, cleaning, testing, or replacement at different intervals. Therefore, environmental classification is not only a design decision: it establishes assumptions for the maintenance plan and asset life expectancy.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">Protection against Overcurrents, Short Circuits, and Faults<\/h2>\n\n\n\n<div class=\"wp-block-a3a-destaque\">\n<p class=\"wp-block-paragraph\">Selecting a circuit breaker and relay alone does not demonstrate selectivity. Fault levels, curves, operating times, and equipment withstand capability need to be assessed as a system to reduce unnecessary outages and thermal exposure.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"\/servicos\/servicos-transversais\/estudo-curto-circuito-seletividade-coordenacao-protecoes\/\">Short-Circuit, Selectivity, and Electrical Protection Coordination Study<\/a><\/p>\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\">A medium-voltage installation needs to be designed to limit the consequences of electrical faults. This involves both the ability of equipment to withstand stresses and the proper operation of protective devices.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">NBR 14039 addresses protection against overload, short circuit, overvoltage, undervoltage and overvoltage, phase loss and phase reversal where applicable, as well as hazards associated with arcing faults. These requirements should not be converted into a generic relay list: the protection philosophy depends on the electrical architecture and system studies.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The short-circuit level is a determining input. It influences device interrupting capacity, thermal and electrodynamic stresses, cable and busbar withstand capability, and protection coordination. For this reason, a mature medium-voltage design should integrate the <a href=\"\/servicos\/servicos-transversais\/estudo-curto-circuito-seletividade-coordenacao-protecoes\/\">short-circuit, selectivity, and protection-coordination study<\/a> into equipment specification.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If upstream protection operates before the protection of the faulty circuit, a localized fault can shut down an unnecessarily large portion of the facility. Conversely, if settings are excessively slow or high, equipment and conductors may remain exposed for a duration incompatible with their withstand capability.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The <a href=\"\/conteudo\/artigos-tecnicos\/coordenograma-curvas-tempo-corrente-seletividade-coordenacao-protecoes\/\">coordination diagram and time-current curves<\/a> turn this coordination into verifiable evidence. They show the relationship among fault currents, operating times, relay, fuse, and circuit-breaker curves, and the thermal limits of protected assets.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">The Short-Circuit Level Must Be Reassessed as the Installation Evolves<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A study performed early in the project&#8217;s life should not be treated as a permanent value. Changes in the utility network, transformer replacement, source paralleling, new on-site generation, BESS, or topology changes can increase or decrease fault currents.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This affects both interrupting capacity and settings. A circuit breaker that was originally adequate may remain physically installed for decades while the electrical system around it changes. Therefore, modernizations and expansions should verify whether the values used for selection and coordination still represent current conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Transformer nameplate data and actual characteristics also need to be considered. Percentage impedance strongly influences secondary short-circuit current. In expansions, simply replacing a transformer with a higher-rated unit can increase fault levels enough to require review of the main low-voltage switchboard, busbars, and downstream protection.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">Arc Flash and Safety Cannot Be Addressed Only through Circuit-Breaker Interrupting Capacity<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Interrupting a short-circuit current and assessing arc-flash risk are related but not equivalent problems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">An installation may have equipment with adequate interrupting capacity and still present high incident energy under certain fault conditions. Protection operating time, arcing current, working distance, and the physical configuration of the installation influence risk.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, when the installation requires a specific assessment, the <a href=\"\/servicos\/levantamento-e-diagnostico\/estudo-energia-incidente-risco-arco-eletrico\/\">incident-energy and arc-flash risk study<\/a> complements the protection analysis. It does not replace NBR 14039; it converts part of the safety philosophy into a quantitative assessment focused on personnel exposure.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The recent update to <a href=\"\/conteudo\/artigos-tecnicos\/nr-10-seguranca-eletrica\/\">NR-10<\/a> reinforces the importance of integrating design, documentation, risk management, and actual operating conditions instead of treating electrical safety as a later documentation step.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">Selection of Medium-Voltage Equipment<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Equipment specifications should relate electrical, mechanical, and environmental characteristics to the actual installation conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For switchgear assemblies, for example, specifying only nominal voltage and current is not enough. The design should consider insulation level, short-time withstand current, interrupting capacity, construction type, compartmentalization, interlocks, access, ingress-protection degree, maintainability, and interfaces with protection, metering, and automation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Transformers also require a systems view. Rating, transformation ratio, vector group, impedance, losses, thermal class, cooling method, insulation type, accessories, and environmental conditions need to be compatible with the application. The article on <a href=\"\/conteudo\/artigos-tecnicos\/transformador-potencia-subestacoes\/\">power transformers in substations<\/a> examines these decisions in detail.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Current and voltage transformers need to meet metering and protection requirements simultaneously. Saturation, accuracy class, burden, and transformation ratio can directly affect relay performance. A CT selected only by nominal current may be inadequate to reproduce fault currents with the accuracy required by the protection function.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Isolation, control, and protection devices should also be assessed from an operational perspective. Interlocks, safe positions, the ability to ground the circuit, and switching sequences are part of preventing operational errors and enabling safe maintenance.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">Selection of Medium-Voltage Cables and Electrical Lines<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Selecting a medium-voltage cable depends on much more than its nominal current.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">NBR 14039 addresses line types, single-core and multicore cables, external influences, current-carrying capacity, short-circuit stresses, voltage drop, connections, and installation requirements. This means final ampacity depends on the installation system and actual thermal conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As applicable, the design should assess installation method, ambient or soil temperature, thermal resistivity, grouping, burial depth, proximity between circuits, solar exposure, ventilation, load profile, and short-circuit effects.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Short-circuit thermal verification is especially important. A cable that normally carries load current may not thermally withstand a fault for the time required for protection to operate. Sizing needs to correlate fault current, duration, and conductor and insulation withstand capability.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Terminations, joints, connectors, and interfaces with switchgear cubicles and transformers also need to be coordinated. At medium voltage, assembly or cable-preparation defects can compromise electric-field gradients, insulation, and reliability even when conductor cross-section is correct.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Why Cable Installation Is as Important as Cable Specification<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Medium-voltage cables have layers with distinct electrical functions, and termination preparation requires geometric control and cleanliness. Damage to semiconductive layers, contamination, moisture, mechanical stress, or improper bending can create electric-field concentrations and degradation points.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The physical route also needs to be coordinated with other disciplines. Cable trays, crossings, spare capacity, bending radii, clearances, sealing, and accessibility for future replacement should be defined before construction.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In brownfield projects, this verification becomes even more important. A new cable may have adequate electrical capacity, while the existing route may not accommodate the required diameter, bending radius, clearances, or thermal dissipation.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">Grounding and Equipotential Bonding in NBR 14039<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Grounding in a medium-voltage installation simultaneously contributes to personnel safety, protection operation, and installation behavior during faults.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">NBR 14039 addresses earthing connections, protective conductors, and equipotential bonding. In a substation, the design needs to consider earth-fault currents, step and touch voltages, interconnection of exposed conductive parts, neutrals, metallic structures, fences, equipment, and other elements that may assume hazardous potentials.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A <a href=\"\/conteudo\/artigos-tecnicos\/malha-de-aterramento\/\">grounding grid<\/a> should not be reduced to obtaining a resistance value in ohms. Performance depends on grid geometry, soil resistivity, fault currents, potential distribution, equipotential-bonding connections, and integration with the protection architecture.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In existing installations, isolated measurements without documentation can lead to incomplete conclusions. The <a href=\"\/servicos\/planejamento\/projeto-de-aterramento\/\">grounding design<\/a> should establish criteria and interfaces, while field verification needs to confirm continuity, connections, and behavior consistent with the design.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Another frequently overlooked aspect is the progressive change of the surrounding environment. Civil expansions, new metallic structures, fences, piping, and equipment can alter the original equipotential relationships. Documentation and the inspection plan need to track these changes.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">What NBR 14039 Requires from Technical Documentation<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Documentation is not an accessory product of the installation. It is part of the mechanism that allows the system to be operated, maintained, modified, and verified safely.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The standard requires installation documentation, and its practical application should result in a coherent set of drawings, diagrams, specifications, equipment data, and records representing the condition actually implemented.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Documents normally required for a medium-voltage installation include:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>updated single-line diagram;<\/li><li>drawings and cable routes;<\/li><li>design reports and sizing criteria;<\/li><li>equipment specifications;<\/li><li>short-circuit and protection studies;<\/li><li>relay settings and files;<\/li><li>grounding documentation;<\/li><li>transformer and switching-device data;<\/li><li>test records;<\/li><li>identification of circuits and components;<\/li><li>as-built documentation.<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The <a href=\"\/conteudo\/artigos-tecnicos\/diagrama-unifilar-subestacao\/\">substation single-line diagram<\/a> is especially important because it summarizes the electrical architecture, isolation points, transformers, busbars, protections, and main interfaces.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When existing documentation differs from field conditions, any subsequent study is compromised. Before changing protection, expanding load, or implementing generation, the actual installation configuration needs to be known.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Design Documentation, Construction Records, and As-Built Documentation Have Different Functions<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The design records the technical intent and criteria defined before construction. Construction records document installed equipment, approved deviations, tests, commissioning, and decisions made during implementation. The As-Built consolidates the final configuration.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Confusing these three layers creates a recurring problem: the organization retains the drawing originally issued for construction even though the installation was modified in the field. Years later, a team uses that drawing to study expansion or maintenance and starts from an incorrect assumption.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The <a href=\"\/servicos\/implementacao\/as-built-documentacao-tecnica-encerramento\/\">Engineering As-Built<\/a> should therefore be treated as technical closure of the lifecycle, not merely as a graphical revision of drawings.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">Final Verification: Inspection and Testing before Energization<\/h2>\n\n\n\n<div class=\"wp-block-a3a-destaque\">\n<p class=\"wp-block-paragraph\">Before energization, the acceptance criterion must be verifiable: inspections, tests, settings, records, and documentation need to demonstrate that the installed system corresponds to the design and is ready to operate.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"\/servicos\/servicos-transversais\/comissionamento-aceite-instalacoes-eletricas\/\">Commissioning and Technical Acceptance of Electrical Installations<\/a><\/p>\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\">NBR 14039 dedicates a specific stage to final verification. This shows that compliance cannot be assumed merely because the correct equipment was purchased and installed.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Verification combines visual inspection and testing. Items include continuity of protective conductors and equipotential bonding, insulation resistance, applied voltage where applicable, grounding resistance, manufacturer-recommended tests, and functional tests.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In practice, this stage should answer an objective question: <strong>does what was installed correspond to the design and operate in a verifiable manner before acceptance?<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This requires traceability among documents, equipment, tests, and acceptance criteria. A report that merely states \u201ctested and approved\u201d without method, instruments, measured values, limits, and asset identification provides little technical evidence.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The <a href=\"\/servicos\/servicos-transversais\/comissionamento-aceite-instalacoes-eletricas\/\">commissioning and technical acceptance of electrical installations<\/a> extends this logic to a structured verification of installation, integration, functionality, protection, documentation, and readiness for operation.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What Turns a Test into Acceptance Evidence<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A useful test must allow another person to understand what was verified and compare the result against a criterion.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td>Element<\/td><td>What should be identified<\/td><\/tr><tr><td>Asset<\/td><td>TAG, circuit, panel, cable, or equipment tested<\/td><\/tr><tr><td>Method<\/td><td>procedure, instrument, and test configuration<\/td><\/tr><tr><td>Condition<\/td><td>state of the installation during measurement or testing<\/td><\/tr><tr><td>Result<\/td><td>measured value or observed behavior<\/td><\/tr><tr><td>Criterion<\/td><td>standard, design, or manufacturer limit<\/td><\/tr><tr><td>Conclusion<\/td><td>approved, rejected, or conditionally accepted<\/td><\/tr><tr><td>Traceability<\/td><td>date, responsible person, instrument, and associated record<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">This structure is especially relevant to insulation resistance, grounding, transformation ratios, protection operation, functional tests, and interlocks.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When criteria have not been defined in advance, commissioning tends to become data collection without a decision. Acceptance requirements should therefore originate in the design and procurement specifications.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">Substations: Where NBR 14039 Becomes Most Visible<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The substation section brings together requirements applicable to indoor and outdoor substations, transformer substations, and control and switching substations.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, designing a substation does not consist of selecting a standard arrangement and repeating details. The design needs to reconcile standards requirements, network characteristics, capacity, expansion, selectivity, environment, maintenance, operational safety, access, ventilation, fire protection where applicable, and civil interfaces.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The transformer is only one component of this architecture. Switchgear cubicles, busbars, circuit breakers, disconnect switches, CTs, VTs, relays, cables, grounding grid, auxiliary services, interlocks, and supervisory systems need to operate as an integrated whole.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is precisely why a <a href=\"\/conteudo\/guias-tecnicos\/guia-subestacao-de-energia-projeto-protecao-automacao\/\">Power Substation: Complete Guide to Design, Protection, Automation, and Lifecycle<\/a> serves as a complement to reading the standard: the standard defines minimum requirements, while the design transforms those requirements into a project-specific configuration.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Primary Substations and Substations Should Not Be Designed Only around Available Space<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In existing installations, studies often begin with the question \u201cwhat equipment fits here?\u201d This reverses the proper logic.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Capacity, architecture, protection, short-circuit current, accessibility, maintenance, ventilation, cable routes, operation, and utility requirements should be defined first. The physical arrangement is then developed to accommodate these conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Insufficient space can compromise switching, access, component replacement, and safety during maintenance. The solution may involve redistributing equipment, civil expansion, or changing technology, but the decision should be guided by technical requirements rather than construction convenience alone.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">Expansions, Retrofit, and Brownfield Installations<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Applying NBR 14039 to existing installations requires distinguishing three situations: maintenance of existing condition, equivalent replacement, and changes that alter engineering assumptions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Replacing a component with a truly equivalent one may not require a complete redesign. However, replacing a transformer with a higher-rated unit, adding generation, changing source paralleling, installing new feeders, or modifying the protection philosophy can affect multiple subsystems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">An expansion should verify at least:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>capacity of transformers and busbars;<\/li><li>cable ampacity and withstand capability;<\/li><li>short-circuit levels;<\/li><li>interrupting capacity;<\/li><li>coordination and selectivity;<\/li><li>grounding;<\/li><li>ventilation and environmental conditions;<\/li><li>physical space and accessibility;<\/li><li>metering and utility standards;<\/li><li>documentation and operation.<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Brownfield projects also need to control downtime. A technically adequate solution may be impractical if it requires outages incompatible with operations. The design should therefore consider phases, contingencies, bypass where applicable, switching sequences, and criteria for safe return to service.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Electrical <a href=\"\/conteudo\/artigos-tecnicos\/retrofit-eletrico-modernizar-instalacoes-quadros-protecoes\/\">retrofit<\/a> should be understood as a technical reorganization of capacity, risk, and reliability, not merely replacement of old equipment.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">Maintenance and Operation Are Also Part of the Compliance Lifecycle<\/h2>\n\n\n\n<div class=\"wp-block-a3a-destaque\">\n<p class=\"wp-block-paragraph\">In existing installations, replacing equipment is not always the priority. A structured assessment helps distinguish obsolescence, standards noncompliance, capacity deficits, protection failures, and documentation problems before CAPEX is defined.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"\/servicos\/levantamento-e-diagnostico\/manutencao-diagnostico-modernizacao-subestacoes-media-tensao\/\">Maintenance, Diagnosis, and Modernization of Medium-Voltage Substations<\/a><\/p>\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\">An installation that was compliant on the day of energization may cease to reflect its original assumptions over time.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Load growth, transformer replacement, new motors, distributed generation, BESS, setting changes, panel expansion, insulation aging, grounding changes, and undocumented interventions can alter system performance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">NBR 14039 addresses preventive and corrective maintenance and operation. Technical management should consider equipment condition, connections, insulation, protection, grounding, signaling, documentation, and performance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When an existing installation presents obsolescence, unavailable spare parts, expansion without study, or documentation discrepancies, a <a href=\"\/servicos\/levantamento-e-diagnostico\/manutencao-diagnostico-modernizacao-subestacoes-media-tensao\/\">maintenance, diagnosis, and modernization program for medium-voltage substations<\/a> can transform scattered symptoms into an assessment of condition, risk, and an intervention plan.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Activity frequency should not be determined only by the calendar. Criticality, environment, failure history, manufacturer recommendations, load profile, number of switching operations, and previous inspection and test results should influence the plan.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">How to Verify Compliance with NBR 14039 in an Existing Installation<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A compliance assessment should not begin with a generic checklist. The installation must first be characterized.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The process can be structured into five blocks:<\/p>\n\n\n\n<ol class=\"wp-block-list\"><li><strong>documentation:<\/strong> verify design documents, diagrams, studies, settings, test records, and modification history;<\/li><li><strong>physical condition:<\/strong> inspect equipment, cables, terminations, grounding, access, signage, cleanliness, and integrity;<\/li><li><strong>protection:<\/strong> confirm short-circuit levels, ratings, settings, coordination, and utility interfaces;<\/li><li><strong>tests and measurements:<\/strong> select methods compatible with the assets and identified risks;<\/li><li><strong>traceability:<\/strong> relate each nonconformity to evidence, requirement, risk, and recommended action.<\/li><\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">This method avoids two extremes: considering an installation compliant merely because it is operating, or condemning it because of documentation differences without assessing criticality and technical effect.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The classification of findings should also separate severity from intervention priority. A documentation deviation may require rapid correction because it compromises operational safety, while another physical item may be monitored until a scheduled outage. The decision needs to relate probability, consequence, asset criticality, and intervention feasibility.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When the objective is to technically document the condition found, a <a href=\"\/servicos\/levantamento-e-diagnostico\/laudo-circunstanciado-instalacoes-eletricas\/\">detailed electrical-installation technical report<\/a> can consolidate evidence, deviations, risks, and recommendations under professional technical responsibility.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">How to Procure a Medium-Voltage Design or Upgrade<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The procurement scope should clearly define what will be considered an input condition and what must exist at acceptance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a medium-voltage design, the scope may include surveys, load assumptions, utility interface, electrical architecture, transformation, cables, protection, grounding, specifications, studies, diagrams, and construction documentation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For an upgrade of an existing installation, the scope should also include diagnostic criteria, treatment of field discrepancies, risk prioritization, compatibility with existing assets, and an implementation strategy that avoids unnecessary operational disruption.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Deliverables should be measurable. \u201cSubstation design\u201d is an insufficient description when it does not define level of detail, associated studies, formats, revisions, responsibilities, and acceptance criteria.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A technically structured procurement should define, according to the scope:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>input documents supplied by the client;<\/li><li>required field surveys;<\/li><li>applicable criteria and standards;<\/li><li>capacity and expansion assumptions;<\/li><li>included electrical studies;<\/li><li>interfaces with the utility and other disciplines;<\/li><li>list of deliverables and formats;<\/li><li>number or logic of revisions;<\/li><li>approval responsibilities;<\/li><li>criteria for considering each deliverable accepted;<\/li><li>support during implementation and handling of technical questions;<\/li><li>update to As-Built when included.<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The <a href=\"\/servicos\/planejamento\/projeto-subestacao-media-tensao-cabine-primaria\/\">Medium-Voltage Substation and Primary Substation Design<\/a> service represents this engineering stage for projects that need to transform standards requirements and network conditions into executable documentation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For higher-criticality projects, it may also be necessary to provide for an independent <a href=\"\/servicos\/planejamento\/revisao-validacao-tecnica-projetos-design-review\/\">Design Review<\/a> before implementation. This reduces the risk of discovering incompatibilities only during assembly, energization, or commissioning.<\/p>\n\n\n\n\n<h2 class=\"wp-block-heading\">Final Considerations<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">NBR 14039 should be understood as a technical framework for the lifecycle of medium-voltage electrical installations from 1.0 kV to 36.2 kV. Its value is not in producing a checklist of requirements, but in guiding verifiable decisions on safety, capacity, protection, components, grounding, documentation, inspection, maintenance, and operation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A sound medium-voltage installation results from the combination of correct data, appropriate studies, coordinated design, controlled execution, and final verification with evidence. When these elements are treated in isolation, compliance may exist only on paper.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For new installations, the focus should be on transforming requirements into design and acceptance criteria. For existing installations, the challenge is to reconstruct the actual condition, identify relevant deviations, and plan interventions according to technical priority. In both cases, NBR 14039 is a central reference but needs to be applied together with regulation, connection standards, occupational safety, and the specific characteristics of each project.<\/p>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>Technical References<\/summary>\n<p class=\"wp-block-paragraph\">[1] BRAZILIAN ASSOCIATION OF TECHNICAL STANDARDS. ABNT NBR 14039:2021 \u2014 Medium-voltage electrical installations from 1.0 kV to 36.2 kV. 3rd ed. Rio de Janeiro: ABNT, 2021. Available at: <a href=\"https:\/\/www.abntcatalogo.com.br\/\">https:\/\/www.abntcatalogo.com.br\/<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[2] BRAZILIAN ELECTRICITY REGULATORY AGENCY. Distribution Rules and Procedures \u2014 PRODIST. Bras\u00edlia, DF: ANEEL. Available at: <a href=\"https:\/\/www.gov.br\/aneel\/pt-br\/centrais-de-conteudos\/procedimentos-regulatorios\/prodist\">https:\/\/www.gov.br\/aneel\/pt-br\/centrais-de-conteudos\/procedimentos-regulatorios\/prodist<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[3] BRAZIL. Ministry of Labor and Employment. Regulatory Standard No. 10 \u2014 Safety in Electrical Installations and Services. Available at: <a href=\"https:\/\/www.gov.br\/trabalho-e-emprego\/pt-br\/acesso-a-informacao\/participacao-social\/conselhos-e-orgaos-colegiados\/comissao-tripartite-partitaria-permanente\/normas-regulamentadora\/normas-regulamentadoras-vigentes\/norma-regulamentadora-no-10-nr-10\">https:\/\/www.gov.br\/trabalho-e-emprego\/pt-br\/acesso-a-informacao\/participacao-social\/conselhos-e-orgaos-colegiados\/comissao-tripartite-partitaria-permanente\/normas-regulamentadora\/normas-regulamentadoras-vigentes\/norma-regulamentadora-no-10-nr-10<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[4] INTERNATIONAL ELECTROTECHNICAL COMMISSION. IEC 60909-0:2026 \u2014 Short-circuit currents in three-phase AC systems \u2014 Part 0: Calculation of currents. Available at: <a href=\"https:\/\/webstore.iec.ch\/en\/publication\/68454\">https:\/\/webstore.iec.ch\/en\/publication\/68454<\/a><\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>Frequently Asked Questions<\/summary>\n<div class=\"schema-faq wp-block-yoast-faq-block\"><div class=\"schema-faq-section\" id=\"faq-question-o-que-a-nbr-14039-12217744\"><strong class=\"schema-faq-question\">What Is NBR 14039?<\/strong> <p class=\"schema-faq-answer\">It is the Brazilian standard applicable to the design and execution of medium-voltage electrical installations in the nominal range from 1.0 kV to 36.2 kV. It establishes requirements related to safety, protection, selection and installation of components, grounding, verification, maintenance, operation, and substations.<\/p><\/div><div class=\"schema-faq-section\" id=\"faq-question-a-nbr-14039-se-aplica-a-cabine-prim-ria-7e94b9aa\"><strong class=\"schema-faq-question\">Does NBR 14039 Apply to Primary Substations?<\/strong> <p class=\"schema-faq-answer\">Yes. Primary substations and medium-voltage service-entrance substations normally fall within its scope and must also comply with utility standards, applicable regulation, and other specific standards.<\/p><\/div><div class=\"schema-faq-section\" id=\"faq-question-qual-a-diferen-a-entre-nbr-14039-e-nbr-5410-b40e5740\"><strong class=\"schema-faq-question\">What Is the Difference between NBR 14039 and NBR 5410?<\/strong> <p class=\"schema-faq-answer\">NBR 14039 addresses medium-voltage installations from 1.0 kV to 36.2 kV. NBR 5410 addresses low-voltage electrical installations. The same project may contain sections subject to both standards.<\/p><\/div><div class=\"schema-faq-section\" id=\"faq-question-atender-nbr-14039-significa-atender-nr-10-428d09ab\"><strong class=\"schema-faq-question\">Does Compliance with NBR 14039 Mean Compliance with NR-10?<\/strong> <p class=\"schema-faq-answer\">No. NBR 14039 is a technical installation standard; NR-10 is a regulatory standard for occupational safety and health in electrical work. They have distinct and complementary roles.<\/p><\/div><div class=\"schema-faq-section\" id=\"faq-question-a-nbr-14039-exige-estudo-de-curto-circuito-e-pro-2f951c49\"><strong class=\"schema-faq-question\">Does NBR 14039 Require Short-Circuit and Protection Studies?<\/strong> <p class=\"schema-faq-answer\">The standard establishes requirements for protection against overcurrents, short circuits, and selectivity between devices. Technical demonstration of compliance normally involves short-circuit data, compatible equipment specification, and coordination of protective devices.<\/p><\/div><div class=\"schema-faq-section\" id=\"faq-question-como-avaliar-uma-instala-o-antiga-segundo-a-nbr--f96621c1\"><strong class=\"schema-faq-question\">How Should an Existing Installation Be Assessed against NBR 14039?<\/strong> <p class=\"schema-faq-answer\">The assessment should start from the installation&#8217;s actual condition: documentation, physical inspection, protection, grounding, testing, and modification history. The result should relate evidence, deviations, risks, and corrective actions without assuming that an operating installation is automatically compliant.<\/p><\/div><div class=\"schema-faq-section\" id=\"faq-question-quem-pode-elaborar-projeto-de-m-dia-tens-o-43b9bef1\"><strong class=\"schema-faq-question\">Who Can Prepare a Medium-Voltage Design?<\/strong> <p class=\"schema-faq-answer\">The design and technical activities should be performed by professionals legally authorized and qualified for the responsibilities assumed, observing professional attributions, legislation, and applicable requirements.<\/p><\/div><\/div>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>Complementary Technical Materials<\/summary>\n<h4 class=\"wp-block-heading\">Related Services<\/h4>\n\n<ul class=\"wp-block-list\"><li><a href=\"\/servicos\/planejamento\/projeto-subestacao-media-tensao-cabine-primaria\/\">Medium-Voltage Substation and Primary Substation Design<\/a><\/li><li><a href=\"\/servicos\/servicos-transversais\/estudo-curto-circuito-seletividade-coordenacao-protecoes\/\">Short-Circuit, Selectivity, and Electrical Protection Coordination Study<\/a><\/li><li><a href=\"\/servicos\/servicos-transversais\/comissionamento-aceite-instalacoes-eletricas\/\">Commissioning and Technical Acceptance of Electrical Installations<\/a><\/li><li><a href=\"\/servicos\/levantamento-e-diagnostico\/manutencao-diagnostico-modernizacao-subestacoes-media-tensao\/\">Maintenance, Diagnosis, and Modernization of Medium-Voltage Substations<\/a><\/li><li><a href=\"\/servicos\/planejamento\/revisao-validacao-tecnica-projetos-design-review\/\">Design Review in Engineering Projects<\/a><\/li><li><a href=\"\/servicos\/levantamento-e-diagnostico\/laudo-circunstanciado-instalacoes-eletricas\/\">Detailed Electrical-Installation Technical Report<\/a><\/li><\/ul>\n\n<h4 class=\"wp-block-heading\">Main Content on the Topic<\/h4>\n\n<ul class=\"wp-block-list\"><li><a href=\"\/conteudo\/artigos-tecnicos\/elementos-de-uma-subestacao\/\">Electrical Substation: What It Is, Types, Components, and Operation<\/a><\/li><li><a href=\"\/conteudo\/artigos-tecnicos\/diagrama-unifilar-subestacao\/\">Substation Single-Line Diagram: How to Read Symbols, Bays, and Protections<\/a><\/li><li><a href=\"\/conteudo\/artigos-tecnicos\/transformador-potencia-subestacoes\/\">Power Transformers in Substations: Types, Components, and Specification Criteria<\/a><\/li><li><a href=\"\/conteudo\/artigos-tecnicos\/estudo-protecao-seletividade-coordenacao-ajustes-curvas\/\">Protection and Selectivity Study: Coordination, Settings, Curves, and Engineering Criteria<\/a><\/li><\/ul>\n\n<h4 class=\"wp-block-heading\">Related Technical Content<\/h4>\n\n<ul class=\"wp-block-list\"><li><a href=\"\/conteudo\/artigos-tecnicos\/nbr-5410\/\">NBR 5410: Low-Voltage Electrical Installations, Grounding, SPDs, and Compliance<\/a><\/li><li><a href=\"\/conteudo\/artigos-tecnicos\/calculo-energia-incidente-arco-eletrico-nbr-17227\/\">Incident-Energy Calculation: How NBR 17227 Guides Arc-Flash Risk Analysis<\/a><\/li><li><a href=\"\/conteudo\/guias-tecnicos\/guia-subestacao-de-energia-projeto-protecao-automacao\/\">Power Substation: Complete Guide to Design, Protection, Automation, and Lifecycle<\/a><\/li><li><a href=\"\/conteudo\/whitepapers\/projeto-subestacao-framework-maturidade-requisitos-estudos-implantacao-aceite\/\">Substation Design: Maturity Framework for Requirements, Studies, Implementation, and Acceptance<\/a><\/li><\/ul>\n<\/details>\n","protected":false},"excerpt":{"rendered":"<p>Understand ABNT NBR 14039:2021, its scope for medium-voltage installations from 1.0 kV to 36.2 kV, and requirements for design, protection, cables, grounding, substations, verification, and maintenance.<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"template":"","meta":{"_a3a_global_related_solutions":[],"_a3a_global_related_services":[],"_a3a_global_related_materials":[],"_a3a_post_lang":"en-us","_a3a_translation_group_id":"c9291b3d-acb5-42c6-bc55-847efaf64105","_a3a_i18n_canonical_slug":"nbr-14039-medium-voltage-electrical-installations-requirements-application-2","_a3a_prod_post_id":"","_a3a_lang_url_en-us":"","_a3a_lang_url_es-es":""},"categories":[],"segments":[],"mercados":[],"etapas":[],"class_list":["post-82705","articles","type-articles","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/a3aengenharia.com\/en-us\/wp-json\/wp\/v2\/articles\/82705","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/a3aengenharia.com\/en-us\/wp-json\/wp\/v2\/articles"}],"about":[{"href":"https:\/\/a3aengenharia.com\/en-us\/wp-json\/wp\/v2\/types\/articles"}],"author":[{"embeddable":true,"href":"https:\/\/a3aengenharia.com\/en-us\/wp-json\/wp\/v2\/users\/1"}],"version-history":[{"count":1,"href":"https:\/\/a3aengenharia.com\/en-us\/wp-json\/wp\/v2\/articles\/82705\/revisions"}],"predecessor-version":[{"id":82711,"href":"https:\/\/a3aengenharia.com\/en-us\/wp-json\/wp\/v2\/articles\/82705\/revisions\/82711"}],"wp:attachment":[{"href":"https:\/\/a3aengenharia.com\/en-us\/wp-json\/wp\/v2\/media?parent=82705"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/a3aengenharia.com\/en-us\/wp-json\/wp\/v2\/categories?post=82705"},{"taxonomy":"segments","embeddable":true,"href":"https:\/\/a3aengenharia.com\/en-us\/wp-json\/wp\/v2\/segments?post=82705"},{"taxonomy":"mercados","embeddable":true,"href":"https:\/\/a3aengenharia.com\/en-us\/wp-json\/wp\/v2\/mercados?post=82705"},{"taxonomy":"etapas","embeddable":true,"href":"https:\/\/a3aengenharia.com\/en-us\/wp-json\/wp\/v2\/etapas?post=82705"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}