IEC 60364-7-712:2017: Low Voltage Electrical Installations — Particular Requirements for Solar Photovoltaic (PV) Power Supply
1. Scope
- Applicable to low voltage electrical installations with an AC voltage not exceeding 1000V or a DC voltage not exceeding 1500V.
- Covers standalone systems, grid-connected systems, and hybrid systems.
2. System Classification
- Standalone System: Completely disconnected from the grid, relying on energy storage devices.
- Grid-Connected System: Connected to the grid, capable of delivering power to the grid.
- Hybrid System: Combines the functions of standalone and grid-connected systems, having bidirectional power flow capabilities.
3. Design Requirements
- Selection of Electrical Equipment: Use equipment that complies with relevant safety standards, such as circuit breakers, fuses, and inverters.
- Cable Sizing: Choose appropriate conductor sizes based on maximum current and fault current.
- Environmental Adaptability: Consider factors such as temperature, humidity, dust, and electromagnetic interference at the installation site.
- Protection Measures: Set up protection measures for overload, short circuits, overvoltages, undervoltages, and power outages.
- Grounding Configuration: Select appropriate grounding electrodes and ensure reliable connections for equipotential bonding.
4. Installation Requirements
- Wiring: Consider factors such as site characteristics, supporting structure, accessibility to people or animals, voltage, electromagnetic interference, and potential short circuits or ground faults.
- Support Structure: Ensure that the support structure is sturdy and reliable, capable of withstanding environmental impacts such as wind and snow loads.
- Identification and Documentation: Provide clear operation manuals, maintenance guides, and safety warnings, ensuring that electrical equipment identification complies with international standards.
5. Operation and Maintenance
- Emergency Control: Install emergency control and disconnection devices to quickly cut off power in emergency situations.
- Space Requirements: Ensure that there is sufficient space for the installation, operation, inspection, testing, maintenance, and repair of electrical equipment.
- Regular Inspections: Conduct regular system inspections and maintenance, particularly focusing on the reliability of grounding configurations and protective devices.
6. Energy Efficiency Requirements
- Energy Efficiency Assessment: Use standard-defined energy efficiency assessment methods, including measurement and monitoring.
- Energy Efficiency Rating: Classify systems based on energy efficiency ratings to promote energy efficiency improvements and reduce emissions.
7. Safety Protections
- Heat Effect Prevention: Prevent overheating or arcing that could lead to fire, ensuring electrical installations do not ignite combustible materials.
- Overcurrent Prevention: Prevent electrical faults caused by overcurrent by limiting the magnitude or duration of overcurrent conditions.
- Insulation Failure: Ensure that fault currents generated during insulation failures do not cause overheating of conductors, which could lead to fusing and fire.
8. Special Scene Requirements
- Grid-Connected System: Must have synchronization capabilities with the grid to safely disconnect during grid faults.
- Standalone System: Must have energy storage capabilities to ensure power supply during periods of no sunlight.
- Hybrid System: Balance the characteristics of both grid-connected and standalone systems to ensure safe operation in different modes.
9. Standard Updates
- The latest version released in 2017 contains significant revisions to adapt to the latest technological developments and safety requirements.
10. Other Considerations
- Compliance: Ensure that all design, installation, operation, and maintenance activities comply with local laws, regulations, and standards.
- Training: Operation and maintenance personnel should receive professional training to be familiar with the system’s operating principles and safety procedures.
- Record Keeping: Maintain detailed records of installation, operation, and maintenance to facilitate future inspections and audits.
By following the above guidelines, it can be ensured that solar photovoltaic (PV) power supply systems meet the requirements of IEC 60364-7-712:2017 throughout the design, installation, operation, and maintenance processes, thereby enhancing the safety and reliability of the system.