Chint NM1LE-125S/4300A63A: molded case circuit breaker

Chint NM1LE-125S/4300A63A is a molded case circuit breaker (MCCB) with residual current protection (leakage protection) function. It is mainly used for overload, short-circuit and leakage protection in power distribution systems.

I. Model Meaning and Core Parameters

1. **NM1LE**: Series code, representing a **molded case residual current circuit breaker** with leakage protection function.

2. **125S**:

   - **125**: Frame current rating is 125A, indicating the maximum current-carrying range of the circuit breaker.

   - **S**: Breaking capacity grade is **Standard type**, corresponding to a rated ultimate short-circuit breaking capacity (Icu) of 25kA (for 4-pole products).

3. **4300A**:

   - **4**: Number of poles is **4-pole (4P)**, suitable for three-phase four-wire circuits.

   - **300**: Tripper type is **thermal-magnetic type (dual tripping)**, providing both overload and short-circuit protection.

   - **A**: Accessory code. Combined with industry practices and official data, it may represent an **alarm contact (AL)** here, which is used to send signals when a leakage fault occurs.

4. **63A**: **Rated current**, meaning the maximum continuous current of the circuit breaker during normal operation is 63A.

II. Technical Performance and Functional Features

1. **Basic Parameters**:

   - **Rated Voltage**: AC 400V (for three-phase) / 230V (for single-phase), complying with GB/T 14048.2 and IEC 60947-2 standards.

   - **Leakage Protection Characteristics**:

     - **Rated Residual Operating Current (IΔn)**: 30-50-100mA with three adjustable gears, which can be selected according to scenarios (e.g., 30mA for personal safety protection, 100mA for fire prevention).

     - **Breaking Time**: ≤0.1s, enabling rapid response to leakage faults.

   - **Mechanical Life**: 20,000 operations; **Electrical Life**: 8,000 operations, suitable for scenarios requiring frequent operation.

2. **Breaking Capacity**:

   - The **rated ultimate short-circuit breaking capacity (Icu)** of 4-pole products is 25kA, which can safely cut off the circuit under short-circuit current, with an arcing distance of ≤50mm.

   - The breaking capacity of upgraded models (e.g., those with suffix "G") may be increased to 30kA, but it is subject to the specific model.

3. **Accessories and Extended Functions**:

   - **Alarm Contact (AL)**: When a leakage fault occurs, it triggers an external alarm device through auxiliary contacts, facilitating remote monitoring.

   - **Other Optional Accessories**: Shunt release (for remote circuit breaking), undervoltage release (for protection when voltage is abnormal), auxiliary contacts (for indicating on-off status), etc.

III. Application Scenarios and Installation Requirements

1. **Typical Applications**:

   - **Residential and Commercial Power Distribution**: Used as protection for main incoming lines or branch circuits to prevent safety accidents caused by overload, short-circuit and leakage.

   - **Industrial Control**: Used for protection of motor circuits, achieving precise overload protection in conjunction with thermal-magnetic tripping characteristics.

   - **New Energy Field**: Can be used for AC side protection of DC systems such as photovoltaic inverters and charging piles (compatibility needs to be confirmed).

2. **Installation Conditions**:

   - **Ambient Temperature**: -5℃ to +40℃, with the 24-hour average temperature not exceeding +35℃.

   - **Altitude**: ≤2,000 meters; derating is required for use in high-altitude areas.

   - **Wiring Method**: Front-panel wiring (standard configuration), supporting plug-in or rear-panel wiring (optional accessories required).

   - **Installation Direction**: Vertical or horizontal installation, but it is necessary to ensure that the operating handle is easy to operate.

 IV. International Certifications and Compatibility

1. **Domestic Certifications**:

   - Certified by **CCC (China Compulsory Certification)** with certificate number 2010010307409759, complying with the GB 16917.1 standard.

   - Complies with the **IEC 60947-2** international standard, and is compatible with some overseas markets (e.g., Southeast Asia, the Middle East).

2. **International Market Restrictions**:

   - **Lack of UL Certification**: No record shows that this model has obtained UL certification in the United States, so it is not recommended for direct use in the North American market.

   - **CE Certification**: Some upgraded models (e.g., NXMLE series) may have obtained CE certification, but specific confirmation with the product manual is required.

 V. Precautions and Selection Recommendations

1. **Alternative Models**:

   - For higher breaking capacity, **NM1LE-125H** (H stands for high breaking capacity, Icu=50kA) can be selected.

   - For remote control function, models with **shunt release (SHT)** or **electric operating mechanism (P)** can be selected.

2. **Compatibility Check**:

   - Confirm **Installation Dimensions**: The height of old models (without suffix "G") may differ from that of upgraded models (with suffix "G"), so it is necessary to avoid conflicts with the cabinet.

   - Verify **Accessory Compatibility**: Alarm contacts and auxiliary contacts need to match the circuit breaker body, and some models need to be purchased separately.

3. **Compliance Recommendations**:

   - Note for users in the United States: This model has not obtained UL certification. If it is to be used in the North American market, circuit breakers complying with the UL 489 standard (e.g., products of brands such as Square D and Eaton) should be selected.

   - For export projects, it is recommended to select the **NXMLE series**, as some models of this series have obtained CE and CB certifications and are more adaptable to international standards.

 VI. Reference Materials and Procurement Channels

1. **Official Materials**:

   - *NM1LE Series Residual Current Operated Circuit Breaker Specification (2023 Edition)* provides detailed parameters and installation guidelines.

2. **Procurement Channels**:

   - **International**: Contact Chint Overseas Offices via WhatsApp: 0086-13811255435 to inquire about compatible models.

Advantages and Disadvantages Analysis of Chint NM1LE-125S/4300A63A

As a **molded case circuit breaker with leakage protection function**, Chint NM1LE-125S/4300A63A has clear technical advantages and specific application limitations in power distribution systems. The following is an analysis from six dimensions based on official data, industry standards and user feedback:

I. Core Advantages: Balance between Cost-Effectiveness and Practical Functions

1. **Triple Protection Mechanism**  

It integrates **overload, short-circuit and leakage protection** functions, with the rated residual operating current (IΔn) supporting three adjustable gears of 30-50-100mA. For example, the 30mA gear can accurately protect against personal electric shock, and the 100mA gear is suitable for fire prevention scenarios, meeting the hierarchical requirements for leakage protection in the *Code for Design of Low-Voltage Electrical Installations* (GB 50054).

2. **Standard Breaking Capacity and Reliability**  

The rated ultimate short-circuit breaking capacity (Icu) is **30kA** (standard type), which can handle short-circuit faults in general power distribution systems, with an arcing distance of ≤50mm. Although it is lower than high-breaking-capacity models (e.g., 50kA for H series), it can meet the conventional needs of residential and commercial scenarios, and has obtained **CCC certification** (certificate number 2010010307409759).

3. **Modular Design and Expandability**  

It supports the expansion of accessories such as **alarm contacts, shunt releases and auxiliary contacts**. For example, the alarm contact (AL) can trigger external signals in case of leakage, which is suitable for scenarios requiring remote monitoring. However, the accessory compatibility of old models (without suffix "G") is relatively weak and needs to be strictly matched with the body.

4. **Outstanding Cost-Effectiveness**  

Its price is **more than 30% lower** than that of similar products of imported brands such as Schneider and ABB, while its performance is close to the international mainstream level. For example, the mechanical life of NM1LE-125S reaches 20,000 operations and the electrical life reaches 8,000 operations, which is equivalent to that of Schneider's EasyPact series, but the cost is significantly lower.

 II. Main Disadvantages: Design Limitations and Compatibility Challenges

1. **Lack of International Certifications and Market Restrictions**  

   - **Lack of UL Certification**: It has not passed the US UL 489 standard, so there is a compliance risk when used directly in the North American market.  

   - **Uncertainty about CE Certification**: Only some upgraded models (e.g., NXMLE series) have obtained CE certification, while NM1LE-125S has not clearly obtained this certification, so caution is required for export.

2. **Accessory Compatibility and Installation Limitations**  

   - **Dimension Incompatibility**: The height of the old model (without suffix "G") is 76mm, while that of the upgraded model (with suffix "G") is 72.5mm, which may cause conflicts with the cabinet or operating mechanism.  

   - **Poor Accessory Adaptability**: Alarm contacts and auxiliary contacts need to be purchased separately and strictly matched with the model. Some users reported that additional debugging is required.

3. **Environmental Adaptability and Derating Requirements**  

   - **Derating at High Altitudes**: When the altitude exceeds 2,000 meters, derating by 1% is required for every 100 meters increase in altitude, so it is not suitable for plateau areas.  

   - **Temperature Sensitivity**: Its performance may decrease when the ambient temperature is lower than -5℃ or higher than 40℃, and additional temperature control measures are required.

4. **Operational Convenience and Appearance Details**  

   - **No Remote Control Function**: A shunt release (SHT) or electric operating mechanism (P) needs to be optional to realize remote circuit breaking, which increases the cost.  

   - **User Experience Feedback**: Some users reported that the **screw design is not convenient for installation** and the texture of the shell material is average.

III. Key Parameter Comparison and Alternative Solutions

 IV. Typical Application Scenarios and Selection Recommendations

1. **Recommended Scenarios**  

   - **Domestic Residential Power Distribution**: Used as the main incoming line circuit breaker to provide basic overload, short-circuit and leakage protection.  

   - **Small and Medium-Sized Commercial Premises**: Suitable for cost-sensitive scenarios such as convenience stores and small offices.  

   - **Industrial Auxiliary Circuits**: Used in conjunction with motor protection switches for circuit protection of non-critical equipment.

2. **Scenarios Requiring Caution**  

   - **North American Market Projects**: Due to the lack of UL certification, it is necessary to switch to the Square D QO series or Eaton BR series.  

   - **Environments with High Short-Circuit Current**: For industries such as metallurgy and chemical engineering, it is recommended to select models with a breaking capacity of ≥50kA (e.g., NM1LE-125H).  

   - **Smart Grid Projects**: When remote monitoring function is required, priority should be given to the NXMLE series with communication modules.

3. **Compatibility Check List**  

   - **Installation Dimensions**: Confirm that the cabinet depth is ≥76mm to avoid conflicts with the operating handle.  

   - **Accessory Matching**: AX-type alarm contacts should be selected, and auxiliary contacts need to be adapted to the NM1LE-125S body.  

   - **Derating Calculation**: If installed in an area with an altitude of 2,500 meters, the rated current needs to be derated to 63A × 0.95 = 59.85A.

 V. User Feedback and Improvement Suggestions

1. **Positive Feedback**  

   - **Reliability**: Users reported that "it operates stably after installation, with no false tripping".  

   - **Response Speed**: The leakage breaking time is ≤0.1s, which meets the requirements of the GB 16917.1 standard.

2. **Negative Feedback**  

   - **Appearance Craftsmanship**: "The shell has a strong plastic feel, which is inferior to imported brands".  

   - **Installation Details**: "The wiring screw design is unreasonable, and additional tools are needed for fastening".

3. **Manufacturer's Improvement Directions**  

   - **Upgrade Accessory Compatibility**: Unify the installation dimensions of old and new models to reduce replacement costs.  

   - **Expand International Certifications**: Promote UL/CE certifications to enhance export competitiveness.  

   - **Optimize User Experience**: Adopt tool-free wiring design and improve the texture of the shell.

VI. Summary: Application Scope and Alternative Solutions

Chint NM1LE-125S/4300A63A is a **cost-effective choice in the domestic mid-to-low-end power distribution market**, especially suitable for scenarios that are cost-sensitive and focus on basic protection functions. Its core advantages lie in **functional integrity and price advantage**, but compromises need to be made in terms of **international compliance, accessory compatibility and installation details**. For higher performance or international applications, you can upgrade to **NM1LE-125H** (high breaking capacity) or switch to the **NXMLE series** (supporting CE certification). For the North American market, it is recommended to directly select UL-certified products of Square D or Eaton.

**Final Recommendation**: This model can be prioritized for domestic projects, but it is necessary to verify the installation dimensions and accessory compatibility in advance; for export or high-end projects, it is recommended to select international brands or Chint's NXMLE series.