The CHINT NXM250S-3300/180A Kompaktleistungsschalter (MCCB) is a protective device specially designed for low-voltage power distribution systems, suitable for industrial, kommerziell, and residential applications. The following is a detailed analysis of its technical parameters, application scenarios, selection points, and maintenance suggestions:
- Technische KernparameterChint NB2LE C20 circuit breaker
- Elektrische Leistung
Nennstrom: 180A, suitable for medium to high-load circuits (z.B., Motoren, lighting distribution boxes).
Bruchkapazität:
Class S: Icu (ultimate breaking capacity) = 50kA, ICs (service breaking capacity) = 36kA (72% of Icu), applicable to scenarios where the short-circuit current ≤ 50kA.
Short-time withstand current (Icw): 30Die (1 second), ensuring stable contact closure during faults.
Polzahl: 3P (three-phase), supporting grounding systems such as TN-C-S.
Trip Type: Thermomagnetic (der zweite “3” In 3300 represents thermomagnetic tripping), providing overload long-time delay (Umkehrzeit) and short-circuit instantaneous protection.
Nennspannung: AC 400V (up to 690V supported, but the 250A frame is not applicable at 690V).
- Mechanical Characteristics
Installationsmethode: Fixed type, front-wiring design, compatible with standard 35mm rails.
Operation Mode: Manual closing, supporting remote shunt tripping (accessories need to be selected separately).
Abmessungen: Approximately 105mm (W) × 188mm (H) × 85mm (D), compact size to save distribution cabinet space.
- Umweltanpassungsfähigkeit
Betriebstemperatur: -5°C bis +70°C, adaptable to high-temperature environments (z.B., unairconditioned power distribution rooms).
Altitude: ≤2000m, pollution degree 3, suitable for industrial environments.
- Anwendungsszenarien
- Typische Anwendungen
Power Distribution System: As a branch circuit switch to protect lines from overload and short-circuit faults (z.B., floor distribution boxes in commercial complexes).
Motorsteuerung: Provides direct starting protection for motors below 150kW (needs to be used with contactors).
Renewable Energy: Protection for the output side of photovoltaic inverters, supporting bidirectional current (reverse power feeding capability needs to be confirmed).
- Industry Adaptation
Industrie: Power distribution for factory production lines, pump houses, and other power equipment.
Construction: Control of lighting and air conditioning systems in intelligent buildings.
Infrastructure: Small data centers, hospital emergency power systems.
III. Technical Features and Advantages
- Intelligent Protection Functions
Overload Long-time Delay: Inverse time characteristics, allowing adjustment of the tripping curve according to load characteristics (z.B., motors require extended tripping time).
Short-circuit Instantaneous Protection: Quickly breaks short-circuit current with a response time <10MS.
Undervoltage Protection: Shunt undervoltage release can be selected (needs to be ordered separately), automatically tripping when the voltage is below 70% des Nennwerts.
- High-reliability Design
Arc-guided Contacts: Reduces arc energy and extends contact life to 10,000 electrical operations.
Vibration-resistant Structure: Passed IEC 60068-2-6 vibration testing, suitable for industrial scenarios with frequent start-stop operations.
Flame-retardant Housing: Made of PA66+GF30 material, heat-resistant up to 125°C, compliant with UL94 V-0 Standards.
- Flexible Expandability
Abundant Accessories: Supports auxiliary contacts (AX/AL-M1), alarm contacts (AX/AL-M3), shunt trip coils, usw., enabling remote monitoring and fault alarm.
Phase Spacers: Arc-shaped arc-dividing plates can be selected to enhance interphase insulation and reduce short-circuit arc risks.
- Selection and Installation Suggestions
- Selection Points
Matching Breaking Capacity: Choose Class S (50Die) or Class H (70Die) based on the system short-circuit current. Zum Beispiel, Class S is usually sufficient when the transformer capacity ≤1600kVA.
Trip Unit Type:
Thermomagnetic (3300): Suitable for mixed loads (z.B., motors and lighting combined).
Electromagnetic (3200): Short-circuit protection only, suitable for pure resistive loads.
Accessory Selection:
– Remote control: Shunt trip coil (MX) + Hilfskontakt (AX).
– Leakage protection: Need to select the NXMLE series (z.B., NXMLE-250S/3300-180A).
- Installationshinweise
Verkabelungsspezifikationen: Use 240mm² copper cables (need to crimp OT terminals), tighten with a torque of 8N·m to avoid excessive contact resistance.
Umgebungsbedingungen: The installation location should be well-ventilated to prevent dust accumulation (z.B., regular cleaning is required in textile factories).
Erdungsanforderungen: The metal housing must be reliably grounded with a yellow-green two-color wire, and the grounding resistance ≤4Ω.
- Wartung und Fehlerbehandlung
- Routinewartung
Cleaning and Inspection: Use dry compressed air to remove internal dust quarterly, and check contact wear (replace if wear exceeds 1mm).
Funktionstest: Use a testing box annually to verify tripping characteristics, ensuring that overload protection does not trip within 2 hours at 1.13 times the rated current and trips within 1 hour at 1.45 mal.
- Häufige Fehler und Lösungen
Inability to Close: Check if the energy storage spring is loose or if the trip unit is in the “re-tripping” Position (needs manual reset).
False Tripping: View fault records through the control unit. If it is an instantaneous overcurrent, adjust the short-circuit protection threshold (z.B., increase from 10In to 12In).
Contact Overheating: Check if wiring terminals are loose or if the load has long-term exceeded the rated current (needs to be derated).
- Garantiebestimmungen
– The product comes with a 24-month warranty, and non-human damage can be replaced for free. It is recommended to purchase through CHINT authorized dealers to ensure after-sales service.
- Zertifizierung und Compliance
Inländische Zertifizierung: Passed CCC certification (certificate number 2020980307002101), compliant with GB14048.2 standards.
Internationale Standards: Compliant with IEC 60947-2, but CE certification is not explicitly marked; separate confirmation is required for exports.
VII. Comparison and Alternative Solutions
- Comparison with Other NXM Series Models
NXM250H/3300: Breaking capacity increased to 70kA, suitable for systems with higher short-circuit currents (z.B., parallel transformers).
NXM250S/3300 vs NM1-250S: The NXM series is a new-generation product with a smaller size and higher breaking capacity (NM1-250S has a breaking capacity of 50kA but a larger size).
- Competitor References
Schneider EasyPact NSX250N: Breaking capacity 50kA, supporting electronic trip units, but 30% higher in price.
Delixi CDB6LE-250: 15% lower in price, but breaking capacity is only 40kA, suitable for cost-sensitive civil projects.
VIII. Procurement and Technical Support
Channels: Purchase through CHINT’s official website or contact WhatsApp: 0086-13811255435, and verify the product serial number and CCC mark.
Zusammenfassung: CHINT NXM250S-3300/180A has become an ideal choice for medium and low-voltage power distribution with its high cost-effectiveness, reliable protection performance, and flexible expandability. Bei der Auswahl, focus on matching the breaking capacity and accessory requirements, and conduct regular maintenance after installation to ensure long-term stable operation.
Comparison Between CHINT NXM250S-3300/180A and Schneider MT16N1
The CHINT NXM250S-3300/180A molded case circuit breaker (MCCB) and Schneider MT16N1 air circuit breaker (ACB) differ significantly in technical positioning, functional design, and application scenarios. The following is a comparative analysis of core dimensions:
- Product Positioning and Basic Types
NXM250S: Belongs to MCCB, positioned as a mid-range power distribution protection device, suitable for overload and short-circuit protection of branch circuits, with a rated current covering 180A (250A frame).
MT16N1: Belongs to ACB, positioned as a high-end power distribution core device, mainly used for main inlets or large-capacity circuits, with a rated current up to 1600A, supporting bidirectional current and complex system protection.
- Comparison of Core Technical Parameters
| Parameter | NXM250S-3300/180A | MT16N1 |
| Nennstrom | 180A (250A frame) | 1600A |
| Bruchkapazität | Icu=50kA, Ics=36kA (72% of Icu) | Icu=50kA, Ics=50kA (100% of Icu) |
| Short-time Current | Icw=30kA (1s) | Icw=50kA (1s) |
| Control Unit | Thermomagnetic tripping (basic overload + Kurzschlussschutz) | MIC series intelligent control unit (four-stage protection + communication) |
| Mechanisches Leben | 10,000 electrical operations | 20,000 mechanical operations |
| Installation Mode | Fixed type, front wiring | Fixed/drawer type, supporting rear wiring/mixed connection |
III. Differences in Functions and Expandability
- Depth of Protection Functions
NXM250S: Only provides two-stage thermomagnetic protection (overload long-time delay + short-circuit instantaneous), without selective protection capability, unable to distinguish fault levels.
MT16N1: Achieves four-stage protection (overload long-time delay, short-circuit short-time delay, instantaneous, ground fault) through the MIC control unit, supporting flexible adjustment of protection parameters to realize selective protection and narrow the power outage range.
- Intelligence and Communication Capability
NXM250S: No built-in communication function, requiring a shunt trip coil to achieve remote opening, but cannot access energy management systems (EMS).
MT16N1: Supports communication-type control units such as MIC 6.0D, integrating Modbus, Profibus protocols, enabling real-time monitoring of power quality, fault recording, and seamless docking with smart grids.
- Accessory Ecosystem
NXM250S: Accessories focus on basic control (shunt trip coils, auxiliary contacts), lacking advanced expansion functions.
MT16N1: Provides rich accessories, including phase spacers, door interlocks, electric operating mechanisms, Kommunikationsmodule, usw., supporting reverse power feeding and distributed energy access.
- Application Scenarios and Adaptability
NXM250S:
Typische Szenarien: Commercial building floor distribution boxes, small industrial motor control (≤150kW), residential power distribution systems.
Limitations: Requires manual reset after tripping, no selective protection, unsuitable for scenarios with high requirements for power supply continuity.
MT16N1:
Typische Szenarien: Data center main inlets, hospital emergency power systems, factory power distribution main switches, photovoltaic inverter outlet protection.
Vorteile: Drawer-type structure supports quick replacement, and the intelligent control unit can achieve precise fault positioning, ensuring continuous power supply for critical loads.
- Reliability and Environmental Adaptability
- Strukturelles Design
NXM250S: Molded case packaging, compact size (100×40×3mm, 1kg), but internal contacts and arc extinguishers are small, with higher temperature rise under long-term high loads.
MT16N1: Metal frame + modular design, contact cross-sectional area more than 5 times that of NXM250S, better heat dissipation performance, suitable for long-term full-load operation.
- Environmental Tolerance
NXM250S: Adaptable to -5°C to +70°C, Höhe ≤2000m, but weak vibration resistance, unsuitable for industrial environments with frequent start-stop operations.
MT16N1: Passed IEC 60068-2-6 vibration testing, wider operating temperature range (-5°C bis +70°C), anti-condensation design applicable to high-humidity environments (z.B., underground power distribution rooms).
- Zertifizierung und Compliance
NXM250S: Passed domestic CCC certification, and some models (such as the NXMLE series) comply with CE and CB standards, but international market adaptability is limited.
MT16N1: Entspricht internationalen Standards wie IEC 60947-2, UL, and ship classification societies, supports global project deployment, and has passed ISO 50001 energy efficiency certification, suitable for green energy projects.
VII. Cost and Maintenance
Procurement Cost: The price of NXM250S is about 1/3 Zu 1/2 of MT16N1, suitable for budget-sensitive projects.
Maintenance Cost:
NXM250S: Maintenance-free design, but overall replacement is required after contact wear, with lower single maintenance costs.
MT16N1: Modular design supports component replacement (such as control units, contact groups), but maintenance complexity is higher, requiring professional technicians.
Zusammenfassung: How to Choose?
Scenarios Prioritizing NXM250S:
Limited budget, simple protection requirements (z.B., residential, small commercial), need for quick installation, and no intelligent monitoring requirements.
Scenarios Prioritizing MT16N1:
Main inlets or large-capacity circuits, requiring selective protection and intelligent communication (z.B., Rechenzentren, hospitals), long-term high-load operation, or harsh industrial environments.
The essential difference between the two lies in functional positioning: NXM250S is an economical and practical “branch guardian,” while MT16N1 is a “power distribution hub” ensuring system stability. Users should make comprehensive decisions based on system scale, protection complexity, and long-term operation and maintenance costs.
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