The core difference is that the NA8 is a upgraded and replacement model of the NA1, with comprehensive enhancements in rated current upper limit, breaking capacity, environmental adaptability, contact system and arc-extinguishing technology, while maintaining compatibility in intelligent protection and basic electrical characteristics.
- Comparison of Core Parameters
| パラメータ | NA1 Series | NA8 Series | Difference Description |
| Rated Current Range | 200A ~ 6300A | 200A ~ 7500A | The NA8 supports a maximum of 7500A, covering larger capacity scenarios |
| Rated Ultimate Short-Circuit Breaking Capacity (Icu) | Up to 100kA | Up to 150kA | The breaking capacity of NA8 is increased by 50%, providing more reliable short-circuit protection |
| Rated Operating Voltage | AC 400V/690V | AC 400V/690V | Identical, both suitable for medium and high voltage distribution systems |
| Operating Ambient Temperature | -5°C ~ +40°C (24h average ≤35°C) | -45°C ~ +70°C | The NA8 has significantly enhanced adaptability to extreme environments |
| Breaking Characteristics | Standard breaking | High breaking + zero arcing design | The NA8 features superior arc-extinguishing performance and higher safety |
| Contact System | Traditional design | New contact system + advanced materials | The NA8 has extended electrical service life and reduced maintenance costs |
| Relationship between Icu/Ics/Icw | Varies with different specifications | Icu=Ics=Icw (for some specifications) | The NA8 offers more consistent protection coordination, simplifying model selection |
- Technical Features and Functional Differences
- Intelligent Protection Functions
NA1: Equipped with basic intelligent protection, supporting overload, undervoltage, 短絡, and single-phase grounding protection. Its precise selective protection improves power supply reliability.
NA8: Upgraded based on the NA1, adding advanced measurement and fault recording (capable of recording 8 faults), zone interlocking and other safety features. Some models support current fault early warning, with a higher level of intelligence.
- Leakage Protection Implementation
NA1: Some models have a built-in leakage protection module.
NA8: Leakage protection is achieved by combining the H-type controller, optional leakage protection function and leakage current transformer (LEC) accessory.
- Installation and Operation Characteristics
– Both support 3P/4P pole numbers, drawout/fixed installation, and manual/electric operation.
– The NA8 has an optimized mechanical interlocking and secondary connector design, facilitating easier installation and maintenance.
Ⅲ. Differences in Application Scenarios
| パラメータ | NA1 Series | NA8 Series | Difference Description |
| Rated Current Range | 200A ~ 6300A | 200A ~ 7500A | The NA8 supports a maximum of 7500A, covering larger capacity scenarios |
| Rated Ultimate Short-Circuit Breaking Capacity (Icu) | Up to 100kA | Up to 150kA | The breaking capacity of NA8 is increased by 50%, providing more reliable short-circuit protection |
| Rated Operating Voltage | AC 400V/690V | AC 400V/690V | Identical, both suitable for medium and high voltage distribution systems |
| Operating Ambient Temperature | -5°C ~ +40°C (24h average ≤35°C) | -45°C ~ +70°C | The NA8 has significantly enhanced adaptability to extreme environments |
| Breaking Characteristics | Standard breaking | High breaking + zero arcing design | The NA8 features superior arc-extinguishing performance and higher safety |
| Contact System | Traditional design | New contact system + advanced materials | The NA8 has extended electrical service life and reduced maintenance costs |
| Relationship between Icu/Ics/Icw | Varies with different specifications | Icu=Ics=Icw (for some specifications) | The NA8 offers more consistent protection coordination, simplifying model selection |
- Model Selection Recommendations
- Capacity Expansion: When upgrading the existing NA1 system to over 6300A, the NA8 series is preferred.
- Harsh Environments: For outdoor applications, metallurgical, chemical, new energy and other industries with large temperature fluctuations or harsh environments, select the NA8.
- High Short-Circuit Risk: For locations close to generators, transformers and other equipment with high short-circuit current, choose the NA8 model with 150kA breaking capacity.
- Cost Sensitivity: For conventional building power distribution and general industrial loads, the NA1 can meet performance requirements with higher cost-effectiveness.
- Intelligence Requirements: For applications requiring fault recording, remote monitoring and early warning functions, the NA8 series is preferred.
As an upgraded model of the NA1, the NA8 achieves generational improvements in performance, reliability and environmental adaptability, while maintaining electrical and installation compatibility with the NA1, facilitating the upgrade and replacement of existing projects. Model selection should be comprehensively determined based on load capacity, short-circuit level, environmental conditions and intelligent requirements. For critical systems, it is recommended to prioritize the NA8 to improve power supply safety and stability.
As a fully upgraded version of the NA1, the NA8 is fully compatible with all basic application scenarios of the NA1, and provides superior performance and protection capabilities in scenarios such as extreme environments, large capacity, high short-circuit risk and high intelligence requirements.
- Basic Application Scenarios of NA1 (Fully Supported by NA8)
The NA8 fully covers the standard application fields of the NA1, with compatible electrical characteristics and installation methods, enabling direct replacement and upgrade:
| Series | Optimal Application Scenarios | Unsuitable Scenarios |
| NA1 | Conventional power stations, factories, mines (690V systems), modern high-rise buildings, intelligent buildings, wind power/photovoltaic and other green energy projects | Extreme temperature environments (below -5°C or above 40°C), and scenarios with ultra-high short-circuit current (>100の) |
| NA8 | Full scenario coverage, especially suitable for extreme environments (例えば, frigid zones/desert areas), large-capacity distribution systems (6300A~7500A), high short-circuit risk (>100kA) industrial scenarios, and critical loads requiring advanced fault diagnosis | No obvious restrictions; NA1 can be considered when cost-effectiveness is a priority |
- Additional Enhanced Application Scenarios of NA8 (NA1 Is Restricted or Unsuitable)
With advantages such as performance upgrade (rated current up to 7500A, breaking capacity up to 150kA), enhanced environmental adaptability (-45°C~+70°C), and improved intelligence (8 fault records, harmonic monitoring), the NA8 expands its adaptability to the following scenarios:
- Extreme Environment Scenarios
Frigid Regions: Outdoor power distribution in Northeast/Northwest China, plateau power stations, withstanding low temperatures of -45°C (NA1 only supports -5°C)
High-Temperature Environments: Industrial furnace areas in metallurgical, glass, chemical industries, desert areas, withstanding high temperatures of +70°C (NA1 only supports +40°C)
High Humidity/Salt Spray Environments: Coastal/marine platforms, chemical parks, with optimized protection design to improve reliability
- Large-Capacity Distribution Scenarios
Ultra-Large Factories: Production lines of steel, automotive, semiconductor industries requiring 7500A-level main switches
Data Centers/Cloud Computing: High-density IT loads requiring larger current carrying capacity and more precise protection
Regional Energy Centers: Centralized energy supply systems with multi-power interconnection, requiring high short-circuit breaking capacity (150の)
- High Short-Circuit Risk Scenarios
Proximity to Generators/Transformers : Areas with short-circuit current up to 120-150kA, the NA8 has a 50% higher breaking capacity
Grid Interconnection Nodes : Multi-power parallel connection with superimposed fault current, requiring coordinated protection with Icu=Ics=Icw
Industrial Heavy-Duty Starting : Frequent starting and stopping of large motors with high inrush current, optimized contact system with extended electrical service life
- High Intelligence Requirement Scenarios
Predictive Maintenance : Critical equipment requiring fault recording (8 回) and current fault early warning
Smart Grid Integration : Supporting communication protocols such as Modbus/Profinet, harmonic monitoring, remote monitoring
Enhanced Safety Interlocking : Complex distribution systems requiring advanced zone interlocking and optimized mechanical interlocking
Ⅲ. Core Technical Guarantees for NA8 Supporting NA1 Scenarios
- Electrical Compatibility: Identical rated voltage (400V/690V), installation dimensions, pole numbers (3P/4P) and operation methods (manual/electric), enabling direct replacement and upgrade
- Protection Function Compatibility: Inheriting all basic protection functions of the NA1, adding advanced measurement, fault diagnosis, harmonic analysis and other functions
- Accessory Compatibility: Supporting common accessories of the NA1 (shunt release/undervoltage release, auxiliary contacts), while providing more intelligent accessory options
- Scenario-Adaptive Model Selection Recommendations
| Scenario Type | 代表的な用途 | Core Requirement Matching |
| Power Station and Grid Distribution | Substations, distribution stations, regional grid hubs | Overload/undervoltage/short-circuit/single-phase grounding protection, selective breaking, improving power supply reliability |
| Industrial Production Distribution | Factory production lines, large-scale equipment control, 690V mining systems | High current carrying capacity (≤6300A), resistance to industrial environmental interference, stable performance under frequent operation |
| Modern Building Distribution | High-rise buildings, intelligent buildings, commercial complexes | Hierarchical protection to avoid unnecessary power outages, supporting building automation systems |
| New Energy Projects | Wind power/photovoltaic power stations, エネルギー貯蔵システム | Adapting to new energy characteristics, protecting inverters and grid-connected equipment, supporting intelligent monitoring |
| Data Centers/Hospitals | Critical load locations | High requirement for power supply continuity, precise protection, rapid fault isolation |
The NA8 not only 100% covers all application scenarios of the NA1, but also solves the application limitations of the NA1 in extreme conditions, large-capacity and high-risk scenarios through upgrades in three dimensions: performance, environmental adaptability and intelligence . For model selection, NA1 or NA8 can be chosen according to cost in basic scenarios, while for critical scenarios with higher requirements for power supply reliability and safety, it is recommended to prioritize the NA8 series to obtain more comprehensive protection and longer service life.
コンタクタ,サーキットブレーカー,ソーラーインバーター,電気メーター,太陽電池


