DC-Side Safety Protection Upgrade: Sungrow SG510HX Completes Extreme Test at 4,200 m

HEFEI, China, June 11, 2026 /PRNewswire/ -- Sungrow recently announced that its SG510HX utility string inverter (SG465HX for the Middle East region, offering equivalent performance) successfully completed an extreme safety challenge at a 4,200-meter-altitude PV plant. Conducted under harsh high-altitude conditions, the test aims to identify the product's safety boundary and validate its capability to operate reliably across a wider range of application scenarios with higher standards.

Reversed PV module connections, switch disconnection failures, and lightning surges - any of these faults or external impacts may trigger safety accidents on the DC side. Minor incidents may cause operational shutdowns and economic losses. Severe incidents may even lead to fires and irreversible damage to surrounding ecosystems. To address these challenges, Sungrow has introduced an upgraded DC-side safety protection system featuring redundant shutdown mechanisms, full-coverage temperature sensing and monitoring, and all-condition lightning protection – setting a new benchmark for inverter safety.

Smart Shutdown: Redundancy Protection Blocks Backflow Current

To address the risks of reverse connection of PV strings and other abnormalities, conventional solutions only rely on mechanical switches to interrupt the fault current. In extreme conditions, if that switch fails, the risk increases.

Sungrow has pioneered the industry-first "main and auxiliary mechanical switches with an electronic bypass" multi-layer redundant protection architecture. The main switch isolates DC-side faults within milliseconds, while the auxiliary switch can independently initiate rapid shutdown and support power-up safety self-checks. If both switches fail under extreme conditions, the system instantly triggers bypass conduction through the electronic switch, forming a low-impedance safety bypass for the fault current and maintaining robust protection.

In addition, the inverter integrates an intelligent locking mechanism that automatically locks the main and auxiliary switches, proactively preventing human-error risks such as accidental closing or failure to disconnect.

During the trial, engineers intentionally simulated both a reversed PV module connection and a mechanical switch failure. Without the redundant shutdown, a 5x backflow current surged back into the string, causing continuous overheating until ignition occurred. * By contrast, the inverter with Sungrow's redundant design responded instantly after the mechanical switch failed. The electronic switch rapidly provided a discharge path for the fault current, leaving both the PV modules and the inverter intact.

Smart Temperature Sensing: Zero‑Delay Warning for Loose Connection Risk

Inverters have many connection terminals. During installation or operation, loose terminal connections or abnormal crimping may occur, causing temperature rises that exceed the threshold and create potential fire risks.

Sungrow has embedded high-precision temperature sensors inside its inverters. With real-time NTC sampling and intelligent algorithms, the system actively identifies abnormal temperature rises. When an abnormality is detected, the system immediately issues a warning. If the temperature exceeds the threshold for a specified duration, the inverter automatically shuts down to cut off the fault risk at the source. *

During the trial, when testers intentionally created a loose terminal connection, Sungrow's inverter instantaneously detected the abnormal temperature rise and automatically shut down due to overtemperature. By contrast, an inverter without temperature sensing and monitoring failed to respond after temperatures exceeded safe limits, causing smoke, fire, and the fire quickly spread to the vegetation laid on the nearby ground. *

All-Condition Lightning Protection: Eliminating Lightning Blind Spots with Industry-First Technology

According to the latest data from the World Meteorological Organization (WMO), global warming continues to intensify, increasing the frequency of extreme weather events such as thunderstorms. Utility-scale PV plants are exposed to lightning hazards from construction through grid connection operation. Traditional industry solutions, however, fail to cover 80% of lightning-fault scenarios.

Sungrow has pioneered all-condition lightning protection. By reinforcing the hardware design at lightning-vulnerable points, the technology provides reliable lightning protection during construction with switches open, grid-connected standby, and grid-connected operation.

During the trial, Sungrow's inverter accurately conducts the simulated lightning current into the discharge channel and prevents interference with internal circuits. This technology has obtained CGC Level 4 certification.

In addition to the on-site test above, Sungrow has also adopted 24-hour insulation monitoring and MPPT-level fault localization technologies. These features enable early warnings of insulation faults as well as rapid fault positioning and troubleshooting, thus guaranteeing the safety of the PV plant throughout its entire life cycle.

As global PV plants face increasingly complex application scenarios and more severe climate challenges, Sungrow has established a three-dimensional safety protection system - PDC model, including Prevent, Diagnose, Contain. This enables closed-loop management from source prevention, fault diagnosis, and accident containment, providing stronger safety assurance for PV plants while helping protect surrounding fragile ecosystems.

* All the above procedures were conducted under a professional fire protection testing environment, and no ecological damage was caused in the process.

Contact: 
Sungrow 
Scarlett Rong
rongtianjiao@sungrowpower.com

Photo - https://mma.prnewswire.com/media/2996629/DC_Side_Safety_Protection_Upgrade.jpg
Logo - https://mma.prnewswire.com/media/1344575/Logo.jpg