Chint NXB63 and NXB40 air switches

The core differences between Chint NXB63 and NXB40 air switches are mainly reflected in aspects such as rated current, breaking capacity, pole number options, and application scenarios, as follows:

1. **Rated Current Range**

- **NXB40**: The rated current range is 6A to 40A, which is suitable for circuits with smaller loads, such as household lighting, ordinary sockets, or small appliances (like TVs, computers).

- **NXB63**: The rated current range is 6A to 63A, which can cover larger load requirements, such as air conditioners, electric water heaters, high - power kitchen appliances, or the main incoming line of distribution boxes.

 2. **Breaking Capacity**

- **NXB40**: The rated short - circuit breaking capacity is 4500A (4.5kA), suitable for civil or small - scale commercial environments with small short - circuit currents.

- **NXB63**:

  - The breaking capacity of the basic version is 6kA, suitable for general residential and industrial scenarios.

  - Some models (such as 2P/230V) have a breaking capacity of up to 10kA, which is suitable for industrial or high - power equipment circuits with a high risk of short circuits.

3. **Pole Number and Installation Flexibility**

- **NXB40**: It mainly provides 1P + N pole number, which is suitable for single - phase circuit protection, such as household single - phase power supply systems.

- **NXB63**: It supports multiple pole numbers such as 1P, 2P, 3P, and 4P, and can meet the needs of single - phase and three - phase circuits, such as three - phase power supply for commercial buildings or industrial equipment.

4. **Size and Installation Space**

- **NXB40**: The width of the 1P + N model is 18.8mm, which is compact in size and suitable for scenarios where the distribution box space is limited.

- **NXB63**:

  - The size of 1P is 18.8mm, but multi - pole models are wider. For example, 2P is 36mm, 3P is 54.9mm, and 4P is 72mm.

  - Multi - pole models need to occupy more distribution box space, so the installation position should be planned in advance.

5. **Tripping Characteristics and Protection Types**

- **Tripping curve**: Both provide Type C (5 - 10 times the rated current instantaneous tripping) and Type D (10 - 16 times the rated current instantaneous tripping).

  - **Type C**: Suitable for conventional loads such as lighting and sockets.

  - **Type D**: Suitable for loads with large inrush currents such as motors.

- **Protection function**: Both provide overload and short - circuit protection, but the high - current models of NXB63 (such as 63A) can withstand higher instantaneous inrush currents.

6. **Application Scenarios**

- **NXB40**:

  - **Household scenarios**: Lighting circuits, ordinary sockets, small household appliances (such as refrigerators, washing machines).

  - **Small - scale commerce**: Office lighting, single - phase power supply for small shops.

- **NXB63**:

  - **Household high - power equipment**: Air conditioners, electric ovens, instant water heaters.

  - **Industry and commerce**: Three - phase motor control, main incoming line of distribution boxes, temporary power consumption places (such as construction sites).

  - **High short - circuit risk environment**: Models with a breaking capacity of 10kA are suitable for industrial automation equipment or high - current circuits.

7. **Price and Certification**

- **Price**: Due to its higher current and breaking capacity, NXB63 is usually more expensive than NXB40. For example, the market price of NXB63 4P C40 is about 73.82 yuan, while that of NXB40 1P + N C20 is about 20 - 30 yuan.

- **Certification**: Both have passed the CCC certification, but international certifications such as UL are not clearly mentioned, and they are mainly oriented to the domestic market.

Summary

- **NXB40**: Suitable for civil or small - scale commercial scenarios with small current and low short - circuit risk, it is small in size and low in cost.

- **NXB63**: Suitable for industrial, commercial or household high - power circuits with large current and high short - circuit risk, it has strong breaking capacity and flexible pole number options.

**Selection suggestions**: Choose according to the circuit load requirements and distribution box space. If the load exceeds 40A or higher breaking capacity is required, NXB63 is preferred; for conventional household use, NXB40 is more economical and practical.