{"id":83129,"date":"2026-09-26T11:06:02","date_gmt":"2026-09-26T14:06:02","guid":{"rendered":"https:\/\/a3aengenharia.com\/?post_type=articles&p=83129"},"modified":"2026-09-26T11:06:02","modified_gmt":"2026-09-26T14:06:02","slug":"photovoltaic-grounding-lps","status":"publish","type":"articles","link":"https:\/\/a3aengenharia.com\/en-us\/content\/technical-articles\/photovoltaic-grounding-lps\/","title":{"rendered":"Solar Panel Grounding and Photovoltaic LPS: NBR 16690 and NBR 5419"},"content":{"rendered":"\n

Grounding of solar panels should be understood as part of the protection and equipotential-bonding architecture of the photovoltaic system, not as the simple connection of a module or a direct-current pole to a ground rod. In a photovoltaic array, frames, metallic structures, bonding conductors, the DC side, inverter, AC side, SPDs, and any LPS have different functions and must be coordinated in accordance with ABNT NBR 16690:2019<\/strong>, a ABNT NBR 5410<\/strong> e, quando houver prote\u00e7\u00e3o contra descargas atmosf\u00e9ricas, a s\u00e9rie ABNT NBR 5419:2026<\/strong>.<\/p>\n\n\n\n

The presence of solar panels on a roof also does not, by itself, mean that the building necessarily requires a new LPS. The need for lightning protection must be defined by the assessment applicable to the facility. However, when a photovoltaic system is added to a building that already has an LPS, the new installation may alter roof geometry, introduce metallic structures and electrical lines, and modify conditions considered in the original design. In this situation, integration with the existing LPS must be reassessed.<\/p>\n\n\n\n

It is also necessary to distinguish protective grounding<\/strong>, equipotential bonding<\/strong>, functional grounding<\/strong> e LPS grounding<\/strong>. A NBR 16690 n\u00e3o permite aterrar um condutor vivo do arranjo fotovoltaico por raz\u00f5es de prote\u00e7\u00e3o. O functional grounding de um polo, quando aplic\u00e1vel, \u00e9 uma condi\u00e7\u00e3o espec\u00edfica de projeto e de tecnologia, sujeita a requisitos pr\u00f3prios de isola\u00e7\u00e3o, supervis\u00e3o e prote\u00e7\u00e3o. Essa distin\u00e7\u00e3o evita uma das interpreta\u00e7\u00f5es mais perigosas do termo \u201caterramento solar\u201d.<\/p>\n\n\n\n\n

What does grounding a solar panel mean?<\/h2>\n\n\n\n

In everyday language, \u201cgrounding the solar panel\u201d usually means connecting the module’s metal frame and support structure to the equipotential-bonding system. Technically, however, the design must identify which parts are exposed conductive parts, which have a protective function, which belong to the DC circuit, and which may participate in lightning protection.<\/p>\n\n\n\n

The aluminum frame of a module, metal rails, clamps, support structures, and metallic enclosures can form an extensive conductive surface on the roof. Equipotential bonding seeks to keep these parts in a coordinated electrical condition and provide an intentional path when protection requires their interconnection.<\/p>\n\n\n\n

This is different from connecting the positive or negative conductor of the string to ground. Live conductors of the photovoltaic array remain subject to the specific rules of NBR 16690, and any functional grounding of a pole may exist only under the conditions established for that purpose.<\/p>\n\n\n\n

It is also different from the LPS grounding subsystem. The LPS uses air termination, down conductors, and grounding to conduct and disperse lightning current; photovoltaic equipotential bonding must be coordinated with this architecture without automatically assuming that every protective conductor is sized to carry lightning current.<\/p>\n\n\n\n\n

Which standards apply to grounding photovoltaic systems?<\/h2>\n\n\n\n

The specific design standard for the electrical installations of the photovoltaic array is ABNT NBR 16690:2019<\/strong>, which remains in force. Its scope includes conductors, protective and switching devices, grounding, and equipotential bonding of the array. The standard itself references NBR 5410 and NBR 5419.<\/p>\n\n\n\n

A ABNT NBR 5410<\/strong> provides the basis for low-voltage electrical installations, including protective grounding, PE conductors, and equipotential-bonding principles. The ABNT NBR 5419:2026<\/strong> series addresses lightning protection: risk analysis, external LPS, internal LPS, separation distance, lightning equipotential bonding, and protection of electrical and electronic systems against surges.<\/p>\n\n\n\n

For inspection and commissioning of grid-connected photovoltaic systems, ABNT NBR 16274<\/strong> complements the process with documentation, inspection, and testing requirements. Thus, design, lightning protection, and final verification form connected but non-interchangeable disciplines.<\/p>\n\n\n\n

Reference<\/td>Main application<\/td><\/tr>
ABNT NBR 16690<\/td>PV-array electrical design, grounding, equipotential bonding, SPDs, insulation, and DC side<\/td><\/tr>
ABNT NBR 5410<\/td>low-voltage electrical installation, PE, protection against electric shock, and equipotential bonding<\/td><\/tr>
ABNT NBR 5419:2026<\/td>risk analysis, LPS, separation distance, equipotential bonding, and surges<\/td><\/tr>
ABNT NBR 16274<\/td>documentation, inspection, testing, and commissioning of grid-connected PV systems<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

The article on photovoltaic design<\/a> addresses overall system integration. Here, the focus is exclusively the interface among grounding, equipotential bonding, LPS, and surge protection.<\/p>\n\n\n\n\n

Protective grounding, equipotential bonding, and functional grounding are not the same thing<\/h2>\n\n\n\n

NBR 16690 explicitly distinguishes functions that are often mixed in field practice.<\/p>\n\n\n\n

Protective grounding<\/strong> is a connection to earth made for safety reasons. Equipotential bonding<\/strong> interconnects conductive parts to reduce potential differences. Functional grounding<\/strong> exists for system operation or performance reasons and should not be confused with a protective measure against electric shock.<\/p>\n\n\n\n

The standard recognizes four general situations in the photovoltaic array: functional grounding of non-energized metallic parts, grounding for lightning protection, equipotential bonding of conductive parts, and functional grounding of one array pole when technically applicable.<\/p>\n\n\n\n

This distinction is important because the same installation may have equipotentially bonded frames without any grounded DC pole. Likewise, functional grounding of a pole does not turn that conductor into PE and does not replace equipotential bonding of metallic parts.<\/p>\n\n\n\n

Distinct functions of grounding and equipotential bonding in a photovoltaic system<\/title>