Chint NU6-II G40/440-3P/20KA Surge Protective Device (SPD)

Chint NU6-II G40/440-3P/20KA is a Class II Test Surge Protective Device (SPD) primarily designed for lightning protection and transient overvoltage protection in three-phase power distribution systems. It features a maximum discharge current of 40kA, a nominal discharge current of 20kA, a continuous operating voltage of 440V, a 3-pole configuration, and a voltage protection level of 2.0kV. This device complies with the standards of GB/T 18802.11 et CEI 61643-11, and has obtained certifications such as CQC and CE.

Core Specifications

Functions and Applications

Fonctions principales: Discharges transient energy such as lightning strikes and operational overvoltages, suppresses overvoltages, and protects downstream power distribution equipment and loads from damage caused by electrical surges.

Applications typiques: Lightning protection at the power supply input of three-phase power distribution incoming cabinets, floor distribution boxes, UPS front ends, frequency converters/servo drives, and other industrial control equipment. It can be used in combination with upstream Class I SPDs and downstream Class III SPDs to establish a cascaded protection system.

Selection and Installation Guidelines

1. Scénarios d'application: Suitable for three-phase 380V power distribution systems, especially occasions with significant line voltage fluctuations and a demand for higher Uc, such as industrial power grids and outdoor distribution boxes.
2. Backup Protection: It is recommended to equip with a Type C or Type D circuit breaker/fuse rated at 16-25A to prevent short circuits caused by SPD failures.
3. Exigences de câblage: The cross-sectional area of connecting wires should be ≤16mm². The length of phase wires and ground wires should be as short as possible (≤0.5m) to reduce the impact of line impedance on protection performance.
4. Méthode de montage: 35mm standard DIN rail mounting, occupying 3 modular positions (approximately 54mm in width).

Price Reference and Procurement Tips

The retail price is approximately 180-280 RMB per unit (as of December 2025, excluding tax and installation costs). For bulk purchases (≥10 units), the price can drop to 150-220 RMB per unit. Models with remote alarm (Type F) have a price increase of 10-15%.

Canaux d'approvisionnement: Chint Electric Mall and authorized distributors. It is crucial to verify the model suffix and certification marks to avoid non-standard or refurbished products.

Recommendations for Surge Protective Devices Similar to Chint NU6-II G40/440-3P/20KA

1. Recommendations for International Brands
2. Schneider Electric

iPRU SS Series: A9LM20403 (SS iPRU 40r 3P)

Specifications: In=20kA, Imax=40kA, Uc=350V, 3P., Voltage Protection Level ≤2.0kV

Caractéristiques: Intelligent design, fault indication, and remote monitoring capabilities

Price Reference: Approximately 280-380 RMB per unit

IST Series: IST 40 3P.

Specifications: In=20kA, Imax=40kA, Uc=340V, 3P.

Caractéristiques: Fixed design, taille compacte, ideal for space-constrained environments

Price Reference: Approximately 250-350 RMB per unit

2. ABB

OVR T2 Series: 9AKK108466A4410 (OVR T2 3L 40-440 P TS QS)

Specifications: In=20kA, Imax=40kA, Uc=440V, 3P., Voltage Protection Level ≤1.8kV

Caractéristiques: “TS” indicates with auxiliary contact; “QS” indicates pluggable for easy maintenance

Price Reference: Approximately 300-400 RMB per unit

3. Phoenix Contact

VAL-MS Series: 2817741 (VAL-MS 440/20/3+0)

Specifications: In=20kA, Imax=40kA, Uc=440V, 3P. (no neutral line), Voltage Protection Level ≤2.2kV

Caractéristiques: “Hot-swappable” modular design, enabling replacement without power cutoff, suitable for critical equipment

Price Reference: Approximately 350-450 RMB per unit

4. DEHN

DG M TNC Series: DG M TNC 440

Specifications: In=20kA, Uc=440V, 3P., Short-circuit Withstand Capacity 25kA

Caractéristiques: Compact design with 3-module width, suitable for TNC systems

Price Reference: Approximately 320-420 RMB per unit

DEHNguard SE CI Series: DEHNguard SE CI 440

Specifications: In=20kA, Uc=440V, integrated backup fuse

Caractéristiques: Integration of overvoltage protection and backup fuse, reducing installation space

Price Reference: Approximately 380-480 RMB per unit

5. OBO

V20 Series: V20-C/3-440V (Order No.: 5094710)

Specifications: In=20kA, Imax=40kA, Uc=440V, 3P.

Caractéristiques: Modular design with optional FS (remote signaling) fonction

Price Reference: Approximately 300-400 RMB per unit

1. Recommendations for Domestic Brands
2. DELIXI Electric

CDYN Series: CDYN-II 40kA 3P 440V YX

Specifications: In=20kA, Imax=40kA, Uc=440V, 3P., Voltage Protection Level ≤2.0kV

Caractéristiques: “YX” indicates with remote signaling function for remote fault indication

Price Reference: Approximately 160-260 RMB per unit

DZ47sY Series: DZ47sY-II 20kA 3P 440V

Specifications: In=10kA, Imax=20kA, Uc=440V, 3P.

Caractéristiques: Terminal power distribution type, cost-effective, suitable for household and small-scale industrial applications

Price Reference: Approximately 80-150 RMB per unit

2. Zhongguang Lightning Protection

ZGZNSD Series: ZGZNSD20-F

Specifications: In=20kA, integrated monitoring module, supporting remote monitoring

Caractéristiques: Intelligent design with lightning current and leakage current monitoring, suitable for critical systems

Price Reference: Approximately 220-320 RMB per unit

3. Other Models in Chint Series

NU6-II Series (Non-G Series)

NU6-II 40kA/440V 3P: Same specifications, the absence of “G” indicates no remote alarm

Price Reference: Approximately 180-280 RMB per unit

NXU-II Series (Kunlun Series)

NXU-II G 40kA/440V 3P: Similar positioning and performance to the NU6-II G Series

Price Reference: Approximately 170-270 RMB per unit

III. Comparison Table of Product Specifications

Note: Some parameters are estimated values; refer to official manuals for actual specifications.

1. Suggestions de sélection
2. Selection Based on Budget

Economical (<200 RMB): DELIXI DZ47sY-II Series, Standard Chint Models

Cost-Effective (200-300 RMB): Chint G Series, DELIXI CDYN Series, Schneider IST Series

High-End (>300 RMB): International Brands such as ABB, Phoenix Contact, and DEHN

2. Selection Based on Functional Requirements

Remote Monitoring Needed: Choose models with suffixes like “F”/”YX”/”FS” (par ex., NU6-II G40/440-3P/20KA-F)

Frequent Maintenance Needed: Choose models with “QS” (pluggable) fonction (par ex., ABB OVR T2 Series)

Space Constraints: Consider compact designs (par ex., DEHN DG M Series, only 3-module width)

3. Compatibility Considerations

Backup Protection: All recommended products should be equipped with Type C or Type D circuit breakers/fuses rated at 16-25A

System Compatibility: Confirm compatibility with your power distribution system type (TN-S/TN-C/TT)

Méthode de montage: All products support 35mm standard DIN rail mountin。

1. Summary of Recommendations
2. Best Cost-Effectiveness: Chint NU6-II Series (same-brand alternative) or DELIXI CDYN Series (equivalent performance at a lower price)
3. First Choice for High-End Quality: ABB OVR T2 Series (slightly better protection level) or Phoenix Contact VAL-MS Series (convenient maintenance)
4. Special Requirements:

Remote Monitoring: Schneider iPRU Series or models with “F” suffix

Wind Power/Photovoltaic Systems: DEHN DG M TNC 440 or OBO V20 Series

It is advisable to make a selection based on the actual application scenario, budget, and maintenance requirements, and purchase through official channels to ensure product quality and after-sales service. For more accurate selection, you can provide specific parameters of your power distribution system and protection requirements for further analysis.