Chint 4P Surge Protector NXU-II 40/385

Chint 4P Surge Protector NXU-II 40/385 is a Class T2 surge protective device (SPD) specifically designed for three-phase four-wire power distribution systems. It is suitable for protecting against lightning and operational overvoltage in residential, commercial, and industrial scenarios. The following is a detailed analysis based on the latest technical data and market feedback:

1. Core Technical Parameters and Performance
2. Protection CapabilityChint NXR series thermal overload relays price

Maximum Discharge Current (Imax) : 40kA (8/20μs waveform), which can effectively discharge instantaneous overcurrent caused by direct lightning strikes or induced lightning.

Nominal Discharge Current (In) : 20kA, meeting daily surge protection requirements.

Maximum Continuous Operating Voltage (Uc) : 385V AC, compatible with 380V three-phase systems (such as TT and TN-S grounding systems).

Voltage Protection Level (Up) : ≤1.8kV, ensuring precision equipment (e.g., PLCs, frequency converters) is protected from residual voltage damage.

2. Response Speed and ReliabilityCHINT circuit breaker price

– Response time <25 nanoseconds, enabling immediate activation of protection when a surge occurs.

– Adopts a collaborative work mode of zinc oxide varistors (MOV) and gas discharge tubes (GDT), featuring both high current handling capacity and low residual voltage characteristics.

– Equipped with a built-in thermal trip module, which automatically disconnects the circuit when components age or are overloaded to avoid short-circuit risks, and indicates deterioration status through a red window.

3. Certifications and Standards

– Complies with international and domestic standards such as IEC 61643-11 and GB/T 18802.11, and has obtained CQC, CE, and CB certifications.

– Note: UL certification has not been explicitly obtained; users in the U.S. market need to confirm the applicability of local electrical regulations or choose other compatible models.

1. Application Scenarios and Installation Points
2. Typical Applications

Main distribution cabinets: Used as secondary protection, it can achieve multi-level protection in conjunction with Class T1 SPDs (such as the NXU-I series). A minimum decoupling distance of ≥10m or additional decoupling inductors must be maintained.

Floor distribution boxes: Directly installed at the incoming line end to protect downstream equipment from lightning and operational overvoltage.

Industrial equipment: Suitable for equipment sensitive to voltage fluctuations, such as photovoltaic inverters and motor control centers (MCC).

2. Installation Specifications

Wiring method: The 4P structure needs to be connected to L1, L2, L3 phase lines, and neutral line (N). The cross-sectional area of the grounding wire should be ≥16mm², with a length ≤0.5m and kept short and straight.

Backup protection: A 63A gG type fuse or Type B circuit breaker must be connected in series at the front end to prevent fire caused by SPD failure.

Dimensions: Modular design with a width of 45mm (3 modules), compatible with TH35-7.5mm standard guide rails, requiring compact installation space.

III. Market Feedback and Purchase Recommendations

1. User Reviews

Users report convenient installation and stable protection performance, especially reliable performance in thunderstorm-prone areas. Some users mentioned that “no equipment damage occurred after full configuration of the top-floor distribution box.”

2. Price and Channels

U.S. procurement: For U.S. procurement, please contact via international business WhatsApp: 0086-13811255435. It is recommended to confirm UL compatibility and import tariffs in advance.

3. Alternative Solutions

– If UL certification is required, consider Chint’s NU6-II series (e.g., NU6-II 40/385 4P), which has similar technical parameters to the NXU-II but with a broader certification scope.

– For high-end needs, a T1+T2 combination scheme (such as the NXU-I+II series) can be selected to provide more comprehensive lightning protection.

1. Precautions and Maintenance
2. Environmental Requirements

– Operating temperature range: -40℃~+70℃, humidity ≤95% (no condensation). Avoid installation in flammable, explosive, or corrosive environments.

– Altitude ≤2000m; derating is required for use in high-altitude areas.

2. Regular Inspection

– Check the status indicator window before the annual thunderstorm season; if it is red, the module needs to be replaced.

– It is recommended to use professional equipment to test leakage current (Ile <100μA/pole) and voltage protection level to ensure performance meets standards.

1. Summary

Chint NXU-II 40/385 has become a mainstream choice for surge protection in three-phase systems due to its high cost performance and stable performance. Its modular design, multi-level protection compatibility, and clear status indication make it particularly suitable for small and medium-sized projects. For U.S. users, it is recommended to prioritize confirming UL compliance or selecting alternative models, and purchase through authorized channels to ensure after-sales support. Strictly following decoupling and grounding specifications during installation can maximize its protection effectiveness.