Comprehensive Guide to IEC 61730-1:2023: Photovoltaic (PV) Module Safety Qualification – Part 1: Requirements for Construction

Solar power plant and Photovoltaic Systems Safety Qualification

IEC 61730-1:2023 is a critical standard that sets forth the safety requirements for the construction of photovoltaic (PV) modules. This guide provides a detailed overview of the standard, covering all essential aspects and technical updates to help manufacturers, designers, and testing institutions ensure compliance and enhance the safety and reliability of PV modules.

Scope

The standard applies to PV modules intended for permanent installation in terrestrial applications, including both crystalline silicon and thin-film technologies. It is relevant for modules used in residential, commercial, and industrial settings, and it covers modules with integrated electronics.

Key Technical Updates

3.6.2 Device Category Marking

• II Class Devices with Functional Grounding:
  • The standard has updated the marking requirements for II class devices that include functional grounding. These devices must now clearly display the functional grounding symbol if they meet any of the following criteria:
    • Use II class power input connectors and provide independent functional grounding connections.
    • Use I class power input connectors where the grounding pin is connected only to functional grounding.
    • Use I class power input connectors where the grounding pin is not connected to functional or protective grounding but provides a separate functional grounding connection.
  • The functional grounding symbol must be clearly visible and legible, and it should be placed near the power input connector.

9 Component Testing Methods

• Interconnecting Cables:
  • The scope of testing for interconnecting cables has been expanded. These cables must now comply with the requirements specified in Chapter G.7, similar to power cords.
  • ES2/ES3/PS3 circuits’ interconnecting cables are also required to undergo the soft wire stress relief test outlined in G.7.3.
  • The test involves subjecting the cables to mechanical stress to ensure they do not break or degrade under normal operating conditions.
• Pressurized Liquid-Filled Components (LFC):
  • Chapter G.15 has been updated to include new requirements for LFC components and modular LFC systems.
  • Additional requirements have been added for liquid-cooled equipment with a capacity greater than 1 liter.
  • The LFC components must be tested for their ability to withstand pressure and temperature changes without leaking or failing.
  • The test methods include pressure cycling, thermal cycling, and leak testing.

10 Annex M: Lithium Battery Requirements

• Basic Requirements:
  • Annex M.1 now includes provisions for batteries that can be removed from the device and charged using external battery chargers, provided these chargers are within the scope of the standard.
  • The batteries must be designed to prevent accidental short circuits and must have appropriate protection mechanisms.
• Safety Requirements:
  • Annex M.2.1 has been updated to include IEC 62133-2 as an alternative standard for lithium batteries used in fixed equipment for subsystem power supply applications.
  • Additional safety protection requirements for stationary devices with lithium batteries have been introduced, such as overcharge protection, overdischarge protection, and thermal runaway protection.
• Additional Protective Measures:
  • Annex M.4 has been revised to remove the term “portable” devices, thereby expanding its applicability to non-portable devices.
  • This ensures that all types of devices containing secondary lithium batteries adhere to the same safety standards.
  • The standard now requires that lithium batteries in stationary devices have multiple layers of protection, including mechanical, thermal, and electrical safeguards.

11 Annex S.6: Material Fire Resistance Testing

• Grid Cover Materials, Fabrics, and Mesh Foams:
  • New testing methods and requirements have been added for grid cover materials, fabrics, and mesh foams.
  • These materials must undergo specific combustion tests to ensure their fire resistance properties.
  • The tests include vertical and horizontal flame spread tests, as well as smoke density and toxicity tests.
  • The materials must not ignite, melt, or drip when exposed to flames, and they must not produce toxic smoke.

Detailed Requirements

3.4 Stability and Mechanical Hazard Requirements

• Enclosure Pressure Resistance:
  • The enclosure of battery-powered devices must withstand the pressure generated by one-piece metal ion chemical batteries during fault conditions.
  • The total area of unobstructed openings in the enclosure must meet the values specified in Table 2.
  • A test is conducted by injecting a specified amount of air into a sealed chamber at an initial overpressure of 2070 kPa ± 10%. The overpressure must drop to below 70 kPa within 30 seconds without causing any unexpected damage to the sealed chamber.
  • The test setup must be carefully calibrated to ensure accurate measurement of pressure changes.
  • The device must remain functional and safe after the test, with no signs of physical damage or leakage.

3.5 Mechanical Strength Requirements

• Drop Test:
  • Handheld battery-powered devices, removable batteries, and separable batteries must undergo a free fall test.
  • Before the test, the batteries are fully charged, and the device is dropped three times from a height of 1 meter onto a concrete surface, changing the starting position to vary the impact points.
  • After the test, the device must not catch fire, show visible signs of liquid leakage, or explode.
  • Additionally, the device must still meet the standard requirements for stability, mechanical hazards, electrical clearances, and creepage distances.
  • If there is only a slight leakage of electrolyte, the battery’s voltage and internal resistance should not change significantly within a short period, preventing further reactions that could lead to fire or explosion.
  • The tested samples should be observed for 12 hours after the test to ensure no abnormalities occur.
  • The test environment must be controlled to avoid external factors that could influence the results, such as temperature and humidity.

3.6 Structural Requirements

• User-Accessible Interfaces:
  • User-accessible interfaces between battery system components should not use connectors that conform to IEC 60320 or IEC 60309-2 unless the battery system is adequately protected against incorrect power sources.
  • For user-accessible interfaces (not power connections), the standard recommends avoiding cylindrical connectors with an outer diameter of 6.5 mm or less, or concentric connectors with a diameter of 3.5 mm or smaller, as defined by IEC 60603-11.
  • The interfaces must be designed to prevent accidental disconnection or improper insertion.
  • Clear instructions and warnings must be provided to users to ensure safe handling and operation.
• Thermal Protection:
  • During thermal testing, the outer surfaces of removable and separable batteries should be protected from excessive heat generated by the device during operation or from heated discharge air.
  • Ventilation holes in the battery must not obstruct the normal operation of the device.
  • The thermal testing must simulate real-world conditions, such as high ambient temperatures and direct sunlight exposure.
  • The batteries must be able to dissipate heat effectively to prevent overheating and potential safety hazards.
  • Temperature sensors must be used to monitor the battery’s surface temperature during the test.

Testing and Evaluation

4.1 Quality Control

• Imaging Conditions:
  • Controlled conditions are essential for ensuring the quality of imaged panels and minimizing negative effects on the images.
  • Overexposure and background irradiation can interfere with the electroluminescence (EL) imaging process.
  • PV modules emit light only during acquisition in a dark room, ensuring uniform illumination.
  • However, out-of-focus EL images can still occur due to incorrect lens focusing and should be included in the dataset for comprehensive testing.
  • The imaging equipment must be regularly calibrated to maintain accuracy and consistency.
• Environmental Stress Testing:
  • PV modules must undergo environmental stress testing to ensure they can withstand various conditions, such as extreme temperatures, humidity, and UV exposure.
  • The tests include damp heat, thermal cycling, and UV radiation resistance.
  • Each test must be performed according to the specified parameters and duration.
  • The modules must show no significant degradation in performance or structural integrity after the tests.

4.2 Defect Detection

• Electrical and Mechanical Defects:
  • Minor operational errors during manufacturing, as well as vibrations and shocks during transportation and installation, can cause module damage.
  • Common defects include cracks, solder corrosion, and cell interconnect breakage, which can render PV modules unusable.
  • Microcracks, though difficult to observe, can significantly affect future output power and the module’s lifespan.
  • They may cause power attenuation ranging from 0.9% to 42.8% and potentially lead to hot spot effects.
  • Advanced imaging techniques, such as electroluminescence (EL) and photoluminescence (PL), are recommended for detecting microcracks.
• Current-Voltage (I-V) Curve Analysis:
  • The I-V curve is a primary method for detecting heavily degraded PV modules.
  • Changes in I-V characteristics can indicate significant issues, such as shading, soiling, or internal faults.
  • However, tiny cracks may not affect the I-V curve, making them challenging to identify through this method alone.
  • Electroluminescence imaging is recommended for more accurate defect detection.
  • The I-V curve analysis must be performed under standardized conditions to ensure comparability and reliability of the results.

4.3 Electrical Safety Requirements

• Insulation Resistance:
  • PV modules must have sufficient insulation resistance to prevent electrical leakage and ensure user safety.
  • The insulation resistance is measured between the module frame and the electrical circuit.
  • The minimum acceptable insulation resistance is specified in the standard.
  • Regular testing is required to ensure ongoing compliance.
• Dielectric Withstand Test:
  • The dielectric withstand test is performed to verify the module’s ability to withstand high voltage without electrical breakdown.
  • The test involves applying a specified voltage between the module frame and the electrical circuit for a defined period.
  • The module must not show any signs of electrical breakdown, such as arcing or insulation failure.
  • The test must be conducted in a controlled environment to ensure accurate results.

4.4 Environmental Protection

• Waterproofing:
  • PV modules must be designed to prevent water ingress, which can cause electrical failures and reduce performance.
  • The standard specifies the IP (Ingress Protection) rating required for different types of modules.
  • Testing methods include water spray, immersion, and pressure water tests.
  • The modules must show no signs of water ingress or electrical shorts after the tests.
• Corrosion Resistance:
  • PV modules must be resistant to corrosion, which can occur due to exposure to salt, chemicals, and other environmental factors.
  • The standard outlines specific corrosion resistance tests, such as salt mist testing and chemical resistance testing.
  • The modules must show no significant corrosion or degradation after the tests.
  • Regular maintenance and inspection are recommended to ensure long-term corrosion resistance.

Documentation and Compliance

5.1 Design Documentation

• Detailed Design Information:
  • Manufacturers must provide detailed design documentation for their PV modules, including material specifications, construction methods, and safety features.
  • The documentation must be clear and comprehensive, allowing for easy review and verification by testing institutions.
  • Any changes to the design must be documented and retested to ensure continued compliance with the standard.
• Testing Reports:
  • All testing must be documented in detailed reports, including test methods, results, and any deviations from the standard.
  • The reports must be signed and dated by the testing personnel and reviewed by a qualified engineer.
  • Testing reports must be made available to customers and regulatory bodies upon request.

5.2 Labeling and Marking

• Compliance Markings:
  • PV modules must be clearly marked with the necessary compliance symbols and information, such as the IEC 61730-1:2023 logo, serial numbers, and manufacturing dates.
  • The markings must be durable and resistant to weathering and wear.
  • Instructions for installation and maintenance must be included on the module or in accompanying documentation.
• Warning Labels:
  • Warning labels must be affixed to the module to alert users of potential hazards, such as electrical shock and high temperatures.
  • The labels must be easily readable and positioned in a location where they are visible during installation and operation.
  • Specific warning messages and symbols are provided in the standard for consistent application across different modules.

Conclusion

IEC 61730-1:2023 is a comprehensive and updated standard that addresses the safety and construction requirements for PV modules. By adhering to the detailed provisions and testing methods outlined in this standard, manufacturers can ensure that their modules meet the highest safety and performance standards. This guide aims to assist stakeholders in understanding and implementing the key requirements of IEC 61730-1:2023, contributing to the overall quality and reliability of photovoltaic modules in various applications.

The standard’s focus on detailed and rigorous testing, coupled with clear documentation and labeling requirements, helps to minimize risks and enhance the longevity of PV modules. As the photovoltaic industry continues to grow, adherence to such standards is crucial for maintaining consumer trust and ensuring sustainable development.

Essential IEC Standards for Photovoltaic Systems: Design, Safety, and Performance Guidelines

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