Power surges are sudden voltage spikes that seriously damage the equipment in a photovoltaic system. These transient overvoltages occur mainly due to atmospheric discharges (lightning) and maneuvers in the electrical network – for example, switching and sudden load fluctuations.
Lightning striking (directly or indirectly) a nearby grid or solar structure induces extremely high voltages in the cables. Similarly, fluctuations and switching in the public grid generate smaller voltage spikes, but they can still burn out sensitive electronic components.
The heart of the system, which converts direct current (DC) from the s into alternating current (AC) for the grid, is especially vulnerable to surges. A single surge can fry the inverter’s internal circuitry or drastically reduce its lifespan. Solar s, charge controllers and other equipment are also at risk. The effects range from blown fuses to irreversible damage to electronic boards, causing system shutdowns and financial losses.
Fortunately, there is a simple and effective device to prevent this damage: the DPS (Surge Protection Device). The DPS acts as a relief valve and under normal conditions it is inactive, but when it detects a voltage spike, it starts conducting and diverts the overvoltage to ground (earthing), preventing excessive energy from reaching the system equipment.
In other words, the equipment protects against power surges, whether caused by lightning or fluctuations in the electrical grid. As soon as the surge es, the DPS returns to standby mode (open circuit). This quick action saves your inverter and other devices from a potentially catastrophic electrical shock. In short, surge protection is as important as circuit breakers or other safety items: it preserves the integrity of the photovoltaic system in the face of unpredictable events.
Protection on the DC and AC sides: SPDs across the entire system
Compliance with Resolution 1.000/2021 and safety standards
In addition to being a common sense measure to protect your investment, using SPDs in PV systems is a matter of regulatory compliance and safety obligation. ANEEL (National Electric Energy Agency), through Normative Resolution No. 1.000/2021, consolidated the rights and duties regarding consumers’ electrical installations.
This regulation requires that solar plants connected to the grid follow current technical and safety standards, ensuring the integrity of the installation and the safety of people, which include several exposed electrical components (s, metal structures, extensive cabling), which places them in the categories of greatest risk of overvoltage due to lightning according to Brazilian standards, such as the AQ3 classification of NBR 5410, a reference standard for low-voltage installations, which determines the mandatory use of surge protection devices in circuits subject to lightning (risk categories AQ2 and AQ3), which must be protected by or equivalent. In other words, protection against overvoltages is not only recommended, but mandatory in risk scenarios such as open-air photovoltaic systems.
From a regulatory perspective, failure to comply with these requirements has serious consequences. Resolution 1.000/2021 allows distributors to inspect installations and punish irregularities that endanger safety. If any technical or safety deficiencies are found in the consumer's installation that pose an imminent risk of damage to people, property or the electrical system, the distributor may immediately suspend the supply of energy to that system.
In other words, a photovoltaic installation without the necessary protections (such as DPS in the necessary locations) is considered irregular to the point of being subject to emergency shutdown. Even when the problem does not pose an immediate risk, the consumer/integrator is notified to correct the fault; if he does not do so within the established deadline, the distributor may interrupt the supply as a penalty for non-compliance.
No one wants to invest in a solar system only to have its operation suspended during an inspection or possible inspection due to the lack of a mandatory safety item. Therefore, complying with the standards – including installing SPDs as required – avoids fines, rework, forced interruptions and legal headaches, in addition to, of course, ensuring the safety of the connection point to the public grid.
In short, being in compliance with the Resolution 1000/2021 and with technical standards (such as NBR 5410 and NBR 5419 for protection against atmospheric discharges) means protecting lives and assets, and safeguarding your solar project from penalties and civil liabilities. Integrators and technical responsible engineers (RTs) must be aware: failure to install adequate protective devices is seen as professional negligence and can result in sanctions if an incident occurs. Safety is never optional – it is a regulatory and ethical prerequisite in any distributed generation system.
The opinions and information expressed are the sole responsibility of the author and do not necessarily represent the official position of the author. Canal Solar.
An answer
Dear all, I would like to point out here that the omission of adequate coordination and protection equipment for an electrical system, whatever it may be, is a serious error that compromises a company, integrator and engineer. Once the system is implemented and approved by the concessionaire, let us that it is tly liable for any accident. Professor, engineer, master in electrical engineering sciences, designer in photovoltaic generation, energy efficiency and electric vehicle charging stations, including with solar carport.