Chint NM1-125S/3300-63A Molded Case Circuit Breaker

The Chint NM1-125S/3300-63A Molded Case Circuit Breaker (MCCB) is a high-performance power distribution protection device in the NM1 series of Chint Group (CHNT). It is suitable for power distribution systems with an AC frequency of 50Hz and a rated operating voltage up to 690V, и в основном используется для перегрузки, short-circuit, and under-voltage protection. The following is a detailed analysis based on Chint’s official data and industry standards:

1. Core Parameters and Technical Characteristics
2. Основные параметры

Номинальный ток (In): 63А, suitable for the load requirements of the circuit.

Ток кадра (Inm): 125А, indicating the maximum current-carrying capacity of the circuit breaker.

Разрывная способность:

Rated Ultimate Short-Circuit Breaking Capacity (Ику): 35тот (at 400V), meeting the safety requirements of medium and high-risk power distribution scenarios.

Rated Service Short-Circuit Breaking Capacity (Ics): 18тот, ensuring the circuit breaker can operate reliably after multiple faults.

Номер полюса: 3 столбы (the first “3” in 3300), applicable to three-phase four-wire or three-phase three-wire systems.

Характеристики срабатывания:

Thermomagnetic Release (the second “3” in 3300), with both overload long-time delay (inverse time) and short-circuit instantaneous protection functions.

Inverse Time Operation Characteristics: The conventional non-tripping current is 1.05In (no tripping within 2 часы), the conventional tripping current is 1.30In (tripping within 2 часы), and the instantaneous operation is set to 10In±20%.

2. Электрические характеристики

Номинальное напряжение изоляции (Ui): 800В, supporting the compatibility of high-voltage level systems.

Compliance with Standards: ГБ/Т 14048.2 (equivalent to IEC 60947-2), and has obtained certifications such as CCC, КОРАБЛЬ, и CE, ensuring international versatility and reliability.

3. Structural Design

Способ установки: Supports vertical or horizontal installation, flexibly adapting to different cabinet layouts.

Способ подключения: Front-panel wiring (standard configuration); some upgraded models offer plug-in design (например, NM1-125S/3300 63A G).

Arc Flash Distance: ≤50 мм, reducing the risk of damage to surrounding equipment caused by fault arcs.

1. Сценарии применения и типичные конфигурации
2. Области применения

Industrial Power Distribution: Power protection for power equipment such as machine tools and production lines.

Коммерческие здания: Control of distribution boxes and branch circuits in office buildings and shopping malls.

Residential and Small-Scale Infrastructure: Overload protection for indoor main incoming lines or high-power electrical appliances (например, air conditioners, электрические водонагреватели).

2. Accessory Expansion

Auxiliary Functions: Can be equipped with a shunt release (for remote circuit breaking), an under-voltage release (for automatic disconnection when voltage is abnormal), or an alarm contact (for fault status signal output) to meet the needs of intelligent control.

Installation Compatibility: Accessory modules are universal with other models in the NM1 series, facilitating later function upgrades.

III. Usage and Maintenance Recommendations

1. Installation Specifications

Экологические требования: Ambient air temperature ranges from -5℃ to +40℃, высота ≤2000 м, and strong magnetic field interference should be avoided.

Требования к проводке: Tighten terminal bolts to the specified torque (refer to the manual) to ensure reliable contact and prevent overheating.

2. Operation and Maintenance Key Points

Регулярный осмотр: Clean the dust on the housing every six months, check the wear of contacts, and replace them if necessary.

,Fault Troubleshooting: If frequent tripping occurs, it is necessary to check whether the load exceeds the limit, whether the line is short-circuited, or whether the setting value of the release is reasonable.

3. Замена и обновление

New Model Replacement: Since 2021, Chint has launched upgraded platform-type products (models with suffix “G”), such as NM1-125S/3300 63A G. The breaking capacity is increased to 50kA, and the installation dimensions are compatible with the old models, enabling seamless replacement.

Local Procurement: Contact Chint’s authorized distributor via WhatsApp: 0086-13811255435 to obtain spot goods and technical support.

1. Key Considerations for Selection
2. Matching of Breaking Capacity: Select the corresponding breaking level (например, Type S: 35тот, Type H: 50тот) according to the short-circuit current level to avoid equipment damage due to insufficient selection.
3. Adaptation of Tripping Curve: For power distribution scenarios, Type C (5-10 times In instantaneous tripping) is preferred; for motor protection, Type D (10-14 times In) требуется.
4. Certification Compliance: For domestic projects, CCC certification must be confirmed; for export projects, attention should be paid to the standards of the target market (например, CE, NOM).