The NSX250F 250A4P circuit breaker of Schneider Electric is a highperformance molded case circuit breaker (MCCB), specifically designed for threephase fourwire systems, and is suitable for overload, shortcircuit, and undervoltage protection. The following is a detailed analysis of its core parameters, functional characteristics, and application scenarios:
- Core Parameters and Technical Specifications
- Model Analysis
NSX: It is a series of molded case circuit breakers of Schneider, featuring modular design and high breaking capacity.
250: Frame Current, indicating that the maximum carrying capacity of the circuit breaker frame is 250A.
F: Breaking capacity grade, corresponding to 36kA (applicable to the AC 415V system), suitable for medium shortcircuit current environments.
250A: Rated current (In), which is the current value for longterm stable operation.
4P: Fourpole design, which can simultaneously disconnect threephase live wires (L1/L2/L3) and the neutral wire (N), suitable for occasions where neutral wire protection is required (such as residential and commercial buildings).
- Electrical Performance
Rated voltage: AC 415V (applicable to the 60Hz system in the North American market).
Tripping Characteristics
Thermalmagnetic tripping (TM): Standard configuration with overload longtime delay (Ir) and shortcircuit instantaneous (Im) protection, suitable for power distribution lines and motor protection.
Electronic tripping (Mic series): Micrologic tripping units can be optionally configured, supporting advanced protection functions such as shortcircuit shorttime delay (Isd) and ground fault (Ig).
Breaking capacity: 36kA (F grade), which can quickly cut off the shortcircuit current and protect the equipment from damage.
- Mechanical Characteristics
Installation method: Fixed type, plugin type, or drawout type, supporting frontofpanel or rearofpanel wiring.
Operation method: Manual rotating handle or electric operating mechanism, compatible with remote control.
Size and weight: The width is approximately 100mm (4P), with a compact volume, making it easy to install in the distribution box.
- Functions and Application Scenarios
- Core Functions
Overload protection: Through the thermal tripping of the bimetallic strip, it will disconnect with a delay when the current exceeds the rated value (inverse timelag characteristic).
Shortcircuit protection: The electromagnetic tripper will trip instantaneously when the shortcircuit current reaches the set value (such as 10 times In).
Undervoltage protection: An undervoltage release (UVR) can be optionally configured, which will automatically disconnect when the voltage is lower than the set threshold.
Neutral wire protection: The neutral pole (N pole) of the 4P circuit breaker supports two modes:
Type B: No tripper is installed on the N pole, and it breaks synchronously with the phase wires (suitable for scenarios where the neutral wire current is small).
Type C: A tripper is installed on the N pole, and it breaks synchronously with the phase wires (suitable for scenarios where the neutral wire current may be overloaded).
- Typical Applications
Industrial power distribution: Main circuit protection of motor control centers (MCC) and power distribution cabinets.
Commercial buildings: Power distribution for lighting and air conditioning systems in office buildings and shopping malls.
Residential: Threephase incoming line distribution boxes, protecting highpower electrical appliances (such as air conditioners and water heaters).
Data centers: Power protection for small and mediumsized server cabinets (accurate monitoring can be achieved by matching with an electronic tripper).
III. Adaptability to the North American Market
- Certifications and Standards
UL certification: The NSX250F has passed the UL 489 certification, meeting the safety requirements of the North American market, and can be used in 120/240V singlephase or 208/480V threephase systems.
Compliance standards: IEC 609472 (international), UL 489 (North America), GB 14048.2 (China).
- Voltage and Frequency
Rated voltage: AC 415V (compatible with the 208/480V system in North America).
Frequency: 50/60Hz, supporting the 60Hz power grid in North America.
- Installation Specifications
Wiring requirements: Copper core wires conforming to UL standards should be used, and the torque requirement is 1215 N·m (refer to the installation manual for details).
Ambient temperature: 5°C to +40°C, adapting to the climate conditions in most regions of North America.
- Selection and Alternative Solutions
- Selection Suggestions
Type of Tripper
TM (Thermalmagnetic): Economical and practical, suitable for conventional power distribution.
Micrologic 2.2/5.2/6.2: Supports current measurement, communication (Modbus), and custom protection curves, suitable for complex systems.
Accessory Expansion
Auxiliary contact (AX): Indicates the status of the circuit breaker (closed/open).
Shunt trip (MX): Remotely controls the opening of the circuit breaker.
Residual current protection module (VE): Additional residual current protection (optional).
- Alternative Models
ComPacT NSX series: Schneider’s new generation of digital circuit breakers, supporting Internet of Things access, and compatible with the installation dimensions of the original NSX series.
EZD series: Economical molded case circuit breakers with a lower breaking capacity (such as 25kA), suitable for scenarios with limited budgets.
- Price and Supply
WhatsApp (8613811255435)
- Supply Channels
Schneiderhebei china electric CO.,LTD
- Maintenance and Troubleshooting
- Regular Inspections
Mechanical operation: Ensure that the handle moves flexibly without jamming.
Contact status: Regularly clean the contact oxides and replace the worn parts if necessary.
Tripping characteristic test: Use special testing equipment to verify the overload and shortcircuit protection functions.
- Common Faults
False tripping: Check whether the load current exceeds the rated value or whether the tripper parameter settings are incorrect.
Unable to close: Check whether the undervoltage release is powered or whether the energy storage spring has failed.
Contact overheating: Confirm whether the wiring terminals are loose or whether the crosssectional area of the wire is insufficient.
VII. Summary
The NSX250F 250A4P circuit breaker, with its high breaking capacity, modular design, and extensive certifications, has become a reliable choice for threephase fourwire systems in the North American market. Its core advantages include:
High reliability: The combination of a 36kA breaking capacity and thermalmagnetic/electronic trippers ensures rapid protection against short circuits and overloads.
Flexibility: Supports multiple installation methods and accessory expansions, adapting to different application scenarios.
Digital support: Intelligent trippers can be optionally configured to achieve power parameter monitoring and remote management.
- Verification of Core Information in the Quotation Sheet
- Supplier Qualification
Company name: hebei china Electric CO.,LTD
Contact information: The phone/WhatsApp (8613811255435) is consistent with the information on the official website (www.transformerandswitchgear.com), but it is necessary to confirm the identity of the contact person Kent Du through an official channel (such as email).
- Product Information
Model parameters: The breaking capacity of the Schneider NSX250F 4P 250A circuit breaker is 65kA, which complies with the IEC 609472 standard and is suitable for industrial power distribution systems.
Price Comparison
Market reference: The domestic procurement announcement in April 2025 shows that the unit price of this model is WhatsApp (8613811255435) yuan, while the unit price in the quotation sheet is WhatsApp (8613811255435) US dollars (approximately equivalent to WhatsApp (8613811255435) yuan), and the price is basically reasonable.
Bulk discount: The unit price of this product for bulk procurement (≥100 units) can be as low as WhatsApp (8613811255435) US dollars, and it is recommended to further negotiate the price.
- Delivery Terms
EXW terms: The buyer needs to bear the transportation, insurance, customs clearance, and export license fees from the factory to the destination by themselves. It is recommended to entrust a professional freight forwarder (such as DHL Global Forwarding) to handle the logistics, and the estimated transportation cost is about 30005000 US dollars (from Hebei to Nouakchott Port, Mauritania).
- Risk Assessment and Response Strategies
- Payment Risk (100%TT)
Risk points: After the advance payment, the supplier may delay the delivery or provide inferior products.
Response measures
Require the supplier to provide the company account (not a personal account) and a copy of the business license.
It is recommended to adopt the payment method of “30% advance payment + 70% against the copy of the bill of lading”.
- Currency Unit Error
Problem: The total price is marked as “WhatsApp (8613811255435) yuan”, but the unit price is in US dollars, and it should actually be WhatsApp (8613811255435) US dollars.
Handling suggestions: Immediately contact the supplier by email or phone, request a written confirmation of the currency unit and the total price, and clearly correct it in the contract.
III. Operation Suggestions
- Contract Signing
Clear terms
Specify the product model (NSX250F TM250D), technical parameters (breaking capacity 65kA), and acceptance standards (refer to the original Schneider instruction manual).
Agree on liquidated damages for delayed delivery (it is recommended to calculate at 0.5% per day).
Dispute resolution: Select the China International Economic and Trade Arbitration Commission (CIETAC) as the arbitration institution and apply Chinese law.
- Logistics Arrangement
Transportation plan
Transport from the Hebei factory to Tianjin Port by road (about 800 kilometers, with a cost of about 2000 yuan).
Sea freight to Nouakchott Port (about 35 days, with a freight cost of about 3000 US dollars).
Customs clearance documents: Require the supplier to provide the certificate of origin (CO), packing list, commercial invoice, and CE certification.
- Aftersales Guarantee
Warranty terms: Require a 12month warranty period, covering nonhuman damage.
Technical support: Confirm whether the supplier provides installation guidance or onsite services (with an additional cost of about 5000 US dollars).
- Summary and Suggestions
Acceptance of quotation conditions: If the supplier can correct the currency unit error, provide the company account information, and agree to the installment payment, cooperation can be considered.
Please proceed with the next step of operation only after receiving the written confirmation from the supplier. If necessary, a contract template and an analysis of trade terms can be provided.
