- Product Overview
Chint NA8 series Air Circuit Breakers (ACB) are the fully upgraded version of the NA1 series, integrating high breaking capacity, zero arcing design, and intelligent protection. With a rated current range of 200A to 7500A, these breakers are applicable to 50Hz power distribution networks with rated voltages of 400V/690V. They are mainly used for power distribution and protecting lines and equipment against overload, undervoltage, short circuit, single-phase grounding, and other faults. They are particularly suitable for scenarios with extreme environments, large-capacity power distribution, and high intelligent requirements.
- Основные технические параметры
2.1 Basic Electrical Parameters
| Parameter | Спецификация | Примечания |
| Rated Frame Current (Inm) | 1600А, 2500А, 3200А, 4000А, 7500А | Covers the entire product series |
| Номинальный рабочий ток (In) | 200A~7500A | Different current ratings for each frame size |
| Номинальное рабочее напряжение (Ue) | AC 400V/690V | AC 690V for 3200/6300 specifications is under trial production |
| Номинальное напряжение изоляции (Ui) | AC 1000V | Meets high-voltage insulation requirements |
| Rated Frequency | 50Гц | Standard industrial frequency |
| Номер полюса | 3P/4P | Rated current of the 4th pole is selectable |
| Breaking Capacity Class | Н (Standard), H (High Breaking), HU (High-Voltage High Breaking) | H class is available for 2500A and above |
| Rated Ultimate Short-Circuit Breaking Capacity (Ику) | Up to 150kA | Icu=Ics=Icw/1s (for some specifications) |
| Rated Service Short-Circuit Breaking Capacity (Ics) | Up to 150kA | Same as Icu, with better protection coordination |
| Rated Short-Time Withstand Current (Icw) | Up to 150kA/1s | Meets stringent short-circuit impact requirements |
| Ambient Temperature for Use | -45°C ~ +70°C | Far superior to NA1 (-5°C~+40°C), adaptable to extreme environments |
| Степень загрязнения | Class 3 | Complies with GB/T 14048.1 и МЭК 60664-1 стандарты |
| Степень защиты | IP30 | Standard protection level, can be enhanced with accessories |
2.2 Detailed Parameters by Frame Size
NA8-1600 Series
| Номинальный ток (А) | 200 | 400 | 630 | 800 | 1000 | 1250 | 1600 |
| Разрывная способность (Ику) | 55тот(400В) | 55тот(400В) | 55тот(400В) | 55тот(400В) | 55тот(400В) | 55тот(400В) | 55тот(400В) |
| Rated Current of the 4th Pole | 200А | 400А | 630А | 800А | 1000А | 1250А | 1600А |
NA8-2500/3200/4000 Series
| Frame Size | Диапазон номинального тока | Ику(400В) | Ику(690В) |
| 2500А | 1000~2500A | 100тот(Н)/125тот(H) | 75тот(Н)/85тот(H) |
| 3200А | 1600~3200A | 100тот(Н)/125тот(H) | 75тот(Н)/85тот(H) |
| 4000А | 2000~4000A | 100тот(Н)/125тот(H) | 75тот(Н)/85тот(H) |
NA8-7500 Series
| Номинальный ток (А) | 4000 | 5000 | 6300 | 7500 |
| Ику(400В) | 150тот | 150тот | 150тот | 150тот |
| Ику(690В) | 100тот | 100тот | 100тот | 100тот |
III. Breaking Characteristics and Arc Extinguishing System
- Zero Arcing Design: Optimized arc extinguishing chamber structure ensures no arc ejection from the breaker body during short-circuit breaking, improving safety.
- Контактная система: Adopts new material and structural design, significantly extending electrical service life and reducing maintenance costs.
- Arc Extinguishing Medium: Air arc extinguishing, combined with special arc extinguishing grids, featuring fast breaking speed and strong breaking capacity.
- Breaking Time: Short-circuit breaking time ≤20ms, quickly cutting off faults and reducing equipment damage.
- Intelligent Protection Functions
The NA8 series is equipped with M/S/L-type intelligent controllers, providing comprehensive protection functions. Some models support advanced features such as 8-time fault recording, harmonic monitoring, and current fault early warning.
4.1 List of Protection Functions
| Тип защиты | Function Description | Operating Characteristics |
| Защита от перегрузки (л) | Характеристика обратнозависимого времени, with three-stage protection (я>, я>>, я>>>) configurable | Complies with GB/T 14048.2 стандартный |
| Защита от короткого замыкания (S/I) | Short-time delay (С) and instantaneous (я) protection, with configurable thresholds | Short-time delay adjustable from 0.1~0.4s, instantaneous with no delay |
| Ground Fault Protection (G) | Detects single-phase ground faults, with alarm or trip options available | High sensitivity and reliable operation |
| Защита от пониженного напряжения | Detects low line voltage, with configurable delayed operation | Prevents equipment damage under low voltage conditions |
| Overvoltage Protection | Detects high line voltage, with configurable delayed operation | Protects sensitive equipment |
| Phase Failure Protection | Detects three-phase current imbalance, preventing motor operation under phase loss conditions | Accurate operation, avoiding motor burnout |
| Harmonic Monitoring | Supported by some models, monitors grid harmonic content | Early warning of power quality issues |
| Fault Recording | Can record 8 fault events, including fault type, current, and time | Facilitates fault analysis and maintenance |
4.2 Types of Intelligent Controllers
| Controller Type | Application Scenario | Functions |
| Type M | Basic protection requirements | Provides basic protection such as overload, short circuit, and ground fault protection |
| Type S | Standard protection requirements | Adds functions like fault recording and parameter configuration |
| Тип Л | Advanced protection requirements | Supports harmonic monitoring, remote communication, and current fault early warning |
- Характеристики установки и эксплуатации
5.1 Способы установки
| Installation Type | Applicable Scenario | Функции |
| Fixed Type | Limited space, no frequent maintenance required | Simple installation and low cost |
| Drawout Type | Occasions requiring frequent inspection and replacement | Can be pulled out for maintenance without cutting off the main power supply, improving power supply continuity |
5.2 Wiring Methods
- Horizontal Connection: Standard wiring method, suitable for most scenarios.
- Vertical Connection: Saves installation space, ideal for compact distribution cabinet layouts.
- Mixed Connection: Flexible combination according to actual requirements.
5.3 Operation Methods
| Operation Type | Функции | Applicable Scenario |
| Ручное управление | Mechanical handle operation, no power supply required | Standby operation method, suitable for emergency situations |
| Electric Operation | Motor-driven, supports remote control | High automation level, suitable for unattended occasions |
| Stored-Energy Operation | Spring energy storage mechanism, fast closing and opening speed | Improves breaking reliability, suitable for frequent operation occasions |
- Mechanical and Environmental Characteristics
| Parameter | Спецификация | Примечания |
| Механический срок службы | 10,000 операции (drawout type), 20,000 операции (фиксированный тип) | Complies with national standards |
| Electrical Service Life | 1,000 операции (at rated current) | Optimized contact system, extended service life |
| Рабочий механизм | Spring energy storage type | Fast closing and opening speed, not affected by power supply |
| Механическая блокировка | Optimized design, ensuring operation safety | Prevents misoperation and improves reliability |
| Secondary Connector | Improved design, reliable contact | Special for drawout installation, stable connection |
| Altitude | ≤2000m | Derating required when exceeding 2000m |
| Relative Humidity | ≤95% (at 25°C) | Adaptable to humid environments |
| Vibration and Shock Resistance | Complies with GB/T 14048.1 стандартный | Adaptable to industrial vibration environments |
VII. Accessory System
The NA8 series supports a rich range of accessories to meet different application requirements, and some accessories are compatible with the NA1 series.
7.1 Release Accessories
| Accessory Name | Функция | Model Example |
| Шунтовая поездка | Remote control of breaker tripping | NA8-F |
| Undervoltage Release | Automatic tripping when line voltage is undervoltage | NA8-U |
| Overvoltage Release | Automatic tripping when line voltage is overvoltage | NA8-OV |
| Alarm Contact | Sends alarm signal in case of faults | NA8-AL |
| Auxiliary Contact | Provides breaker status signal | NA8-AX (2 нормально открытый, 2 нормально закрытый) |
7.2 Operation Accessories
| Accessory Name | Функция | Applicable Scenario |
| Electric Operating Mechanism | Motor-driven closing and opening | Automatic control systems |
| Rotary Operating Handle | Manual operation of the breaker | On-site operation |
| Locking Device | Locks breaker status to prevent misoperation | Occasions with high safety requirements |
| Padlocking Device | Allows padlocking to prevent unauthorized operation | Public places or critical equipment |
7.3 Protection Accessories
| Accessory Name | Функция | Model Example |
| Leakage Current Transformer (LEC) | Detects leakage current, achieving residual current protection in conjunction with the controller | NA8-LEC |
| Residual Current Protection Module | Provides residual current protection function | NA8-RCM |
| Temperature Sensor | Monitors breaker temperature to prevent overheating | NA8-TS |
VIII. Selection Guide
8.1 Selection by Breaking Capacity
| Breaking Capacity Class | Applicable Scenario | Icu Value (400В) |
| Тип Н (Standard) | Conventional power distribution systems with short-circuit current ≤100kA | 55~100kA |
| Type H (High Breaking) | Occasions with large short-circuit current, например, near transformers | 125~150kA |
| Type HU (High-Voltage High Breaking) | 690V systems with large short-circuit current | 75~85kA |
8.2 Selection by Frame Size
| Frame Size | Диапазон номинального тока | Applicable Scenario |
| 1600А | 200~1600A | Small-sized factories, commercial buildings |
| 2500А | 1000~2500A | Medium-sized factories, high-rise buildings |
| 3200А | 1600~3200A | Large-sized factories, data centers |
| 4000А | 2000~4000A | Extra-large factories, regional energy centers |
| 7500А | 4000~7500A | Ultra-large factories, power grid hubs |
8.3 Selection by Installation Method
– Drawout Type: Recommended for occasions requiring frequent maintenance and breaker replacement, such as critical power distribution circuits.
– Fixed Type: Recommended for occasions with limited space and low maintenance frequency, such as general power distribution circuits.
- Core Differences from NA1 Series
Comparison Item NA8 Series NA1 Series Advantage Description Maximum Rated Current 7500А 6300А Covers larger capacity scenarios Разрывная способность Up to 150kA Up to 100kA 50% improvement, more reliable short-circuit protection Экологическая адаптивность -45°C~+70°C -5°C~+40°C Significantly enhanced adaptability to extreme environments Intelligence Level 8-time fault recording, harmonic monitoring, early warning Basic protection functions Comprehensive improvement in intelligence level Технология дугового тушения Zero arcing design with optimized arc extinguishing chamber Standard arc extinguishing design Higher safety, reduced installation distance Контактная система New material and structure Traditional design Extended electrical service life, lower maintenance cost - Recommended Application Scenarios
- Extreme Environment Scenarios: Frigid regions (-45°C), high-temperature environments (+70°C), high-humidity/salt spray environments (coastal areas/chemical industrial parks).
- Large-Capacity Power Distribution Scenarios: Ultra-large factories (steel/automotive/semiconductor), data centers/cloud computing facilities, regional energy centers.
- High Short-Circuit Risk Scenarios: Proximal ends of generators/transformers (short-circuit current 120-150kA), power grid interconnection nodes, industrial heavy-load starting occasions.
- High Intelligence Demand Scenarios: Predictive maintenance, smart grid integration, complex power distribution systems with enhanced safety interlocks.
- NA1 Upgrade Scenarios: Projects where the original NA1 system needs capacity expansion above 6300A, where environmental conditions are harsh, or where intelligence level needs to be improved.
- Ordering Information
Complete model designation of NA8 series products: NA8-Frame Size-Rated Current-Breaking Capacity/Pole Number-Installation Method-Controller Type
Пример: NA8-7500-5000H/4P-Drawout Type-Type L Controller
XII. Executive Standards
The product complies with the following national and international standards:
- ГБ/Т 14048.2-2018 Low-voltage Switchgear and Controlgear – Part 2: Circuit-breakers
- МЭК 60947-2:2019 Low-voltage switchgear and controlgear – Part 2: Circuit-breakers
Контактор,автоматический выключатель,солнечный инвертор,электрический счетчик,солнечные батареи


