Overview
IEC TS 63346-2-1:2026 is a technical specification developed by the International Electrotechnical Commission (IEC). It outlines the essential design criteria and general requirements for low-voltage auxiliary power systems (APS), crucial for the safe and reliable operation of substations, converter stations, hydropower, and thermal power stations. The standard applies to auxiliary power systems operating at nominal voltages up to 1 kV AC or 1.5 kV DC and frequencies up to 60 Hz.
By providing a structured framework for APS design, IEC TS 63346-2-1:2026 facilitates consistent electrical safety, operational reliability, and adaptability for future modifications across power infrastructure globally.
Key Topics
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Design Principles
- Safety: The APS must protect personnel, equipment, and the overall system from risks such as electric shock, overvoltage, and thermal effects.
- Reliability: The system should assure uninterrupted functioning, considering the criticality and importance of facility operations.
- Flexibility: The design should accommodate future modifications and expansions without compromising performance or safety.
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System Configuration
- AC Systems: Covers supply sources (transformers, generators, converters), distribution boards, load circuits, and earthing methods.
- DC Systems: Includes energy storage (batteries), chargers, transfer switches, distribution panels, monitoring, and protection devices.
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Safety and Protection
- Requirements for preventing electric shock, thermal hazards, overcurrents, and voltage or electromagnetic disturbances according to the IEC 60364 series.
- Emphasis on arc-fault mitigation, explosion protection, and fire safety-including specialized considerations for battery gases.
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Load Classification
- Differentiates critical/essential loads (e.g., control centers, emergency systems) from non-essential loads, influencing backup and redundancy arrangements.
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SCADA and Monitoring
- Integration of measurement, digitization, remote control, and online monitoring to ensure effective management and rapid response to abnormalities.
Applications
IEC TS 63346-2-1:2026 has broad application across various segments of the power industry:
- Substations: Ensures reliable auxiliary power for operations, protection, and control systems at the nodes of transmission or distribution networks.
- Converter Stations: Provides dependable low-voltage support for power conversion, control, and monitoring equipment.
- Hydropower Stations: Supports auxiliary loads, from control gear to monitoring instrumentation, crucial for water-to-energy processes.
- Thermal Power Stations: Addresses the auxiliary power needs for fuel handling, safety interlocks, and emergency systems.
By aligning with IEC 63346-2-1, organizations can reduce downtime, safeguard personnel, and comply with international best practices, ultimately ensuring grid stability and operational excellence.
Related Standards
IEC TS 63346-2-1:2026 references and aligns with several foundational IEC standards, including:
- IEC 60038: Standard voltages for electrical systems.
- IEC 60079-0: Equipment requirements for explosive atmospheres.
- IEC 60364 series: Comprehensive guidelines for low-voltage electrical installations.
- Part 1, 4-42, 4-43, 4-44, 5-51, 5-52, 5-53 for protection, equipment, and wiring.
- IEC 60909-0: Calculation of short-circuit currents in AC systems.
- IEC 61439-1/2: Rules for switchgear and controlgear assemblies.
- IEC TR 61641: Handling internal arc faults in low-voltage assemblies.
- IEC 61643-12: Selection and application of surge protective devices.
- IEC 61660-1: Calculation of short-circuit currents in DC auxiliary installations.
- IEC 61936-1: Power installations exceeding certain voltage thresholds.
- IEC TS 63346-1-1: Terminology for low-voltage auxiliary power systems.
Practical Value
Implementing IEC TS 63346-2-1:2026 ensures:
- Consistency and quality in APS design across global projects.
- Enhanced personnel safety and protection of critical infrastructure.
- Improved system resilience, reducing costly outages and operational risks.
- Compliance with current international best practices in low-voltage auxiliary power systems.
Organizations adopting this standard position themselves for future-proof, scalable, and robust infrastructure supporting the evolving needs of the energy sector.
Open preview (PDF)Low-voltage auxiliary power systems - Part 2-1: Design criteria - General requirements
