Schneider NSX250F MCCB — Specs, Trip Units & Availability

By Abdullah Zahid
16 min read
Schneider Electric ComPacT NSX250F 3-pole 250A molded case circuit breaker for industrial power distribution panels

Schneider Electric ComPacT NSX250F Molded Case Circuit Breaker — 3-Pole, 36 kA at 415VAC: Full Specifications, Trip Unit Guide, and Procurement Advice

If you are specifying or procuring a molded case circuit breaker for a 3-phase industrial distribution system and the ComPacT NSX250F is on your short list, there are two things you need to know before issuing an RFQ: this is a proven 36 kA, 250A MCCB with broad international certifications and genuine field history — and the product line was discontinued in June 2023, meaning specific SKU availability must be confirmed with a specialist distributor before any commitment is made. Whether you are retrofitting existing Schneider Electric infrastructure, protecting a motor feeder in a marine environment, or evaluating the NSX250F against Schneider's new ComPacT successor, this review gives you the technical clarity and procurement context to make the right call.

If you have already confirmed this is the correct part for your application, check current pricing and availability for the ComPacT NSX250F at LeadTime.ca — we ship worldwide and maintain direct relationships with Schneider Electric distribution channels to access legacy inventory.

Who Should Buy the ComPacT NSX250F — and Who Should Specify Something Else

The ComPacT NSX250F is the right choice if your application matches the following profile:

  • You need a 3-pole MCCB rated at 250A (or the 200A or 220A variant) for a 3-phase system at 415VAC
  • Your system fault level requires a breaking capacity of 36 kA at 415VAC — confirmed against your utility short-circuit contribution
  • You require a specific trip unit: TM-D for thermal-magnetic general-purpose protection, MA for motor circuits and soft-starter or VFD compatibility, or Micrologic 2.2 for electronic protection with adjustable thresholds
  • Your application requires IEC 60947-2 compliance, and optionally CCC (China), EAC (post-Soviet states), or marine certification
  • You are retrofitting existing Schneider Electric infrastructure where a direct plug-in replacement is preferred over a platform migration
  • Your distributor has confirmed your specific LV-series catalog number (for example, LV431630 for the TM-D 250A 3P 3D configuration) is in stock or within an acceptable procurement lead time

If you are designing a new system from the ground up, or if your distributor cannot confirm immediate stock for your specific SKU, the new ComPacT range — Schneider Electric's designated successor — is the more prudent specification. Continuing down the NSX250F path on a greenfield design introduces supply chain risk that is avoidable.

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What the ComPacT NSX250F Actually Does in an Industrial Power System

The ComPacT NSX250F is a molded case circuit breaker designed to serve as the primary protective device in medium to heavy industrial electrical distribution. Its core function is automatic disconnection of a 3-phase circuit under two conditions: sustained overload current that would damage conductors or connected equipment, and instantaneous short-circuit current that poses an immediate fault hazard. At 36 kA breaking capacity at 415VAC, it handles the fault levels present on industrial networks fed from medium-voltage transformers without requiring upstream current-limiting equipment in most standard applications.

What distinguishes the NSX250F from simpler MCBs is its trip-unit modularity. The same physical frame accepts a TM-D thermal-magnetic trip module for general distribution loads, an MA pure-magnetic module for motor and soft-starter circuits where inrush tolerance is critical, or a Micrologic 2.2 electronic unit for applications requiring adjustable protection thresholds and advanced selective coordination. This means a panel builder can standardize on a single frame size across multiple protection strategies within one enclosure, reducing inventory complexity and wiring labor.

The ComPacT NSX250F is also integrated into Schneider Electric's EcoStruxure Power architecture, supporting data collection and remote monitoring for predictive maintenance and energy optimization — a capability that becomes relevant in facilities pursuing intelligent power management. One analyzed SKU (LV431630) carries a measured lifecycle carbon footprint of 762 kg CO2 equivalent, providing documented support for corporate sustainability reporting in regulated industries.

Typical System Architecture: Where the NSX250F Sits in Your Distribution Chain

The ComPacT NSX250F sits at the protective boundary between an upstream supply source and one or more downstream load circuits, providing automatic fault isolation without affecting adjacent unfaulted circuits when coordinated correctly.

  • Upstream: Utility transformer secondary or standby generator output — the NSX250F acts as the main incoming feeder breaker at the main distribution board
  • NSX250F installed at the main distribution panel or motor control center — 3-pole connection on incoming line terminals; load-side terminals feed downstream distribution
  • Downstream from NSX250F: Outgoing feeders to sub-distribution panels, motor starters, soft starters, or VFD drives depending on the trip unit selected
  • Alongside: Other NSX250F units on parallel feeders, each protecting a discrete load group, coordinated for selective tripping so a fault on one feeder does not interrupt adjacent circuits
  • Optional: EcoStruxure Power monitoring system connected via Micrologic 2.2 electronic trip unit for real-time load data and remote fault diagnostics

Industries and Applications Where the NSX250F Is Deployed

In manufacturing environments — machine tool shops, food processing lines, automotive assembly, and textile production — the ComPacT NSX250F protects 3-phase feeder circuits that supply large motor loads and general distribution boards. Its 36 kA breaking capacity handles the fault levels common on transformer-fed panels in heavy production facilities, and the TM-D trip unit provides reliable overload protection for fixed-load circuits without nuisance tripping during normal production variation.

In motor circuit protection roles, the MA trip unit variant is the correct specification. Large pumps, compressors, and fan drives draw high inrush current during startup that a thermal-magnetic trip unit would interpret as a fault. The MA module responds only to instantaneous magnetic overcurrent, ignoring the inrush transient while still providing short-circuit protection. For soft-starter and VFD applications in water treatment, HVAC, and process industries, this distinction is the difference between a reliable installation and a commissioning headache.

Marine vessel power distribution is one of the NSX250F's strongest application fits. The breaker carries marine classification approval alongside IEC 60947-2, CCC, and EAC certifications — a compliance breadth that allows a single SKU to serve ship distribution panels across multiple flag-state jurisdictions. This multi-certification profile also makes the NSX250F appropriate for data centers and UPS output protection in hospitals and mission-critical facilities, where selective coordination and proven reliability under fault conditions are non-negotiable.

In mining, petrochemical, and refining environments, the combination of 36 kA breaking capacity and a compact frame that fits standard distribution enclosures reduces the engineering overhead of fault-level system studies. The operating temperature range of -20 to +60°C accommodates both outdoor switchgear enclosures in cold climates and hot utility rooms in tropical industrial facilities.

Application Typical Deployment
Incoming feeder protection Main 3-phase distribution board fed from utility transformer or generator; TM-D trip unit standard
Motor circuit protection Large pumps, compressors, fan drives; MA trip unit for soft-starter and VFD compatibility
Load-center distribution Secondary distribution point splitting power to multiple sub-circuits; selective coordination with downstream MCBs
Marine vessel power Ship distribution panel; marine certification; IEC 60947-2 compliant for multi-flag deployment
UPS and mission-critical systems Inverter output protection in hospitals and data centers; Micrologic 2.2 for selective coordination
Mining and heavy industry High-fault-level networks; 36 kA breaking capacity; -20 to +60°C operating range

Key Specifications for Purchase Decision Confidence

Parameter Value Notes
Poles 3 Standard; 2d and 3d mounting variants available
Rated Current 250 A 200A and 220A variants also available — confirm load before ordering
Rated Voltage 415 VAC 3-phase system typical; verify for your site voltage
Breaking Capacity (Icu) 36 kA at 415VAC Confirm against utility short-circuit contribution
Trip Unit Options TM-D, MA, Micrologic 2.2 Must be specified explicitly — not interchangeable at ordering stage
Standards Compliance IEC 60947-2, CCC, EAC, Marine Verify regional certification requirement before ordering
Operating Temperature Range -20 to +60°C Standard industrial ambient range
Switching Capacity Up to 500,000 cycles Typical industrial duty rating
Mounting DIN rail or bolt-on Verify with distributor for your specific configuration
Lifecycle Carbon Footprint 762 kg CO2 eq Per LV431630 SKU; varies by trip unit selection

Full technical specifications are available on the product page at LeadTime.ca.

TM-D vs. MA vs. Micrologic 2.2: Choosing the Right Trip Unit for Your Load

Trip unit selection is the most common source of wrong-part orders on the ComPacT NSX250F, and it cannot be corrected after delivery without a module swap. The three available options address fundamentally different protection strategies, and specifying the wrong one either leaves motor circuits vulnerable to nuisance tripping or leaves general distribution loads under-protected against sustained overloads.

Trip Unit Type Best For Protection Mechanism Selectivity
TM-D Thermal-Magnetic General industrial distribution, fixed loads, lighting, heating Thermal element for overload + instantaneous magnetic for short-circuit Standard
MA Pure Magnetic Motor circuits, soft starters, VFD-driven loads Magnetic only — no thermal element; tolerates motor inrush without tripping Good
Micrologic 2.2 Electronic Selective coordination applications, diagnostics, mission-critical distribution Electronic algorithm with adjustable long-time, short-time, and instantaneous thresholds Excellent

If your load schedule includes motors above 10 HP, soft starters, or VFDs, the TM-D is the wrong choice — the thermal element will interpret motor inrush as an overload and trip during startup. The MA module eliminates this problem. If your project requires documented selective coordination studies or real-time diagnostic data via EcoStruxure Power, only the Micrologic 2.2 provides the adjustable thresholds and communication interface to support that analysis. Check current availability for your preferred trip unit configuration at LeadTime.ca — trip unit selection must be confirmed at ordering, not assumed.

Expert Verdict: When to Buy the NSX250F and When to Migrate

The ComPacT NSX250F has earned its position as a global industrial standard through decades of deployment in manufacturing, marine, mining, and mission-critical power distribution. Its 36 kA breaking capacity at 415VAC delivers protection headroom that satisfies the fault-level requirements of most industrial networks without requiring system upgrades, and its multi-trip-unit architecture — TM-D, MA, and Micrologic 2.2 in a single frame — allows panel builders to address diverse load profiles within one standardized enclosure. The compliance breadth covering IEC 60947-2, CCC, EAC, and marine certification is a genuine operational advantage for integrators and facility managers deploying across multiple regions or jurisdictions. For retrofit projects in existing Schneider Electric infrastructure, for marine vessel panels requiring certified MCBBs, and for regional markets where new ComPacT stock availability is still developing, the NSX250F remains a technically sound and field-proven specification.

Where the calculation changes is new system design and long-term procurement planning. The NSX250F line reached end-of-primary-support status in June 2023, with Schneider Electric's new ComPacT range designated as the successor platform. Buyers specifying the NSX250F for greenfield installations face a supply chain that is in controlled decline — specific LV-series SKUs such as LV431630 may be unavailable or carry 6 to 12 week lead times on special order. If your project cannot absorb that uncertainty, or if long-term spare-parts continuity and access to advanced IoT integration through EcoStruxure Power are priorities, the new ComPacT range is the correct specification. Budget-sensitive projects should also evaluate total cost of ownership across the support lifecycle, not just unit price, before committing to NSX250F stock.

The procurement reality is straightforward: do not order on generic "NSX250F" nomenclature. You need an explicit LV-series catalog number, a confirmed trip unit, a verified pole and mounting configuration, and a distributor who can provide a committed delivery date rather than an estimate. Specialist distributors maintain the direct Schneider Electric relationships and legacy inventory access that generic e-commerce channels simply cannot offer for a discontinued product line. Confirm your specific SKU availability and current pricing at LeadTime.ca — our team has the technical staff and distribution access to verify stock, advise on trip-unit selection, and support migration to the new ComPacT range if that is the better path for your project.

For volume pricing, project-specific lead time confirmation, or guidance on NSX250F-to-new-ComPacT migration, contact the LeadTime.ca team directly — we ship worldwide and can source across North American and international distribution hubs.

What Engineers Need to Know Before Ordering the ComPacT NSX250F

Because the ComPacT NSX250F is an industrial B2B component purchased through authorized distribution channels rather than consumer retail, public forum discussions are essentially absent. Procurement and technical validation for safety-critical MCCBs happen through manufacturer technical hotlines, panel builder relationships, and specialist distributors — not Reddit threads or enthusiast forums. This means buyers specifying the NSX250F for the first time, or returning to the market after the June 2023 discontinuation announcement, are operating with limited peer reference data. What follows is the most important pre-order intelligence drawn directly from manufacturer documentation and distributor-reported ordering patterns.

The most consequential mistake is treating "NSX250F" as a complete part specification. It is not. The NSX250F designation describes the frame and breaking capacity — 36 kA at 415VAC in a 250A molded case — but it does not specify the rated current (200A, 220A, and 250A variants exist within the same frame), the trip unit (TM-D, MA, or Micrologic 2.2), the pole configuration (3-pole standard; 2d or 3d mounting depending on neutral handling), or the regional certification (marine, CCC, EAC). An order placed on the basis of the frame name alone will almost certainly produce a parts mismatch, a project delay, or both. Every order must be placed using the specific LV-series catalog number that encodes all of these selections — and that catalog number must be verified as currently available before committing.

The discontinuation status introduces a second layer of risk that does not exist with in-production MCCBs. Some regional variants and distributor stockpiles remain available, but availability is deteriorating and is not uniform across markets. Buyers in China and EAC regions may find NSX250F stock flowing through regional channels longer than buyers in North America or Western Europe. The lead time gap between in-stock and special-order is significant: 2 to 4 weeks for available stock, versus 6 to 12 weeks for discontinued SKU procurement — a difference that can determine whether a project ships on time or not. Engaging a specialist distributor with direct Schneider Electric access before finalizing your BOM is the single most effective way to avoid this risk. LeadTime.ca maintains the distributor relationships and technical expertise to verify real-time availability, advise on trip-unit selection for your specific load, and map your NSX250F specification to the equivalent new ComPacT SKU if a migration path is the right outcome for your project.

Installation and Wiring Overview

The following covers the key requirements and pre-installation verifications for the ComPacT NSX250F. Full installation procedures are detailed in Schneider Electric's official technical manual, which should be referenced for all commissioning work.

  • Verify the distribution enclosure meets IEC or NEMA thermal and ventilation ratings before mounting; operating temperature range is -20 to +60°C and adequate airflow must be maintained around the breaker body
  • Mount on DIN rail or bolt-on surface as applicable to your configuration; confirm 2d (2-pole plus neutral) or 3d (3-pole plus neutral) mounting requirement against your panel design — these are not interchangeable
  • Incoming line phases connect to top terminals; outgoing load phases connect to bottom terminals; if using a 3d configuration, connect neutral at the dedicated neutral terminal — torque all terminals to the values specified in the manufacturer manual
  • Trip unit wiring varies by type: TM-D and MA are self-contained mechanical modules requiring no external power; Micrologic 2.2 electronic units require verification of auxiliary supply connection before commissioning
  • Before energizing, perform manual handle operation with no load connected to confirm smooth mechanical action and proper reset function; do not force the handle if it does not return cleanly to the closed position

Wrong-Part Prevention Checklist

Before finalizing your RFQ or purchase order for the ComPacT NSX250F, confirm every item on the following checklist. These points reflect the most consequential specification errors that result in wrong deliveries, project delays, and safety compliance failures:

  1. DO NOT assume 250A — verify actual load current and select correct rating (200A, 220A, or 250A variants exist)
  2. DO confirm breaking capacity is 36 kA at YOUR system voltage (415VAC typical; other voltages may differ)
  3. DO specify trip unit explicitly: TM-D (thermal-magnetic, general purpose), MA (pure magnetic, motor protection), or Micrologic 2.2 (electronic smart protection with diagnostics)
  4. DO verify pole/phase requirement: NSX250F standard is 3-pole for 3-phase; do NOT order if application is single-phase or 2-pole
  5. DO check mounting config: 2d (2-pole + neutral) vs. 3d (3-pole + neutral) — selection depends on distribution board design
  6. DO confirm your specific SKU is in stock; do NOT assume LV431630 or similar legacy codes are available — NSX250F line discontinued, check distributor availability
  7. DO verify marine/regional certification requirement before ordering; some markets require specific approval (CCC for China, EAC for post-Soviet states)

If any item on this checklist cannot be confirmed before your order is placed, contact the LeadTime.ca team — our technical staff can work through each specification point with you and verify current stock status for your exact LV-series SKU before you commit.

Frequently Asked Questions

Is the ComPacT NSX250F truly discontinued, and can I still buy it?

The NSX250F product line was phased out in June 2023, with Schneider Electric's new ComPacT range designated as the successor. However, regional distributor inventory and some production variants remain available through authorized channels. Availability varies by SKU, region, and current stock levels — it is not uniform across markets. The critical step is contacting an authorized specialist distributor to verify your specific LV-series catalog number is in stock before committing your BOM. Do not assume availability based on the frame name alone.

What happens if I specify TM-D for a motor circuit — will it nuisance-trip?

Yes, in most cases it will. The TM-D thermal-magnetic trip unit responds to sustained overcurrent using a thermal element that cannot distinguish between motor startup inrush and a genuine overload condition. Motor inrush current — typically 6 to 8 times full-load current during startup — will trip a TM-D unit. Motor circuits, soft-starter applications, and VFD-driven loads require the MA pure-magnetic trip unit, which has no thermal element and responds only to instantaneous short-circuit level overcurrent, ignoring the inrush transient entirely.

Can the trip unit be swapped in the field after installation, or must it be specified at the point of order?

The ComPacT NSX250F frame is designed to accept different trip unit modules, and field swap is mechanically possible. However, given that the NSX250F line is discontinued, sourcing a replacement or upgraded trip unit module separately carries the same availability risk as ordering the complete breaker. Specifying the correct trip unit at the initial order stage is strongly recommended. If a trip unit change is required after installation, contact your distributor to confirm module availability before committing to the swap.

How do I confirm my system's short-circuit level is within the 36 kA breaking capacity?

The prospective short-circuit current at your installation point is determined by your utility's fault contribution and the impedance of the transformer and cabling between the source and the breaker. This figure appears in your electrical system's short-circuit calculation report or can be requested from your utility provider. If your calculated prospective fault current at the installation point is at or below 36 kA at 415VAC, the NSX250F breaking capacity is sufficient. If your fault level exceeds 36 kA, you require a higher-rated MCCB — this is a non-negotiable safety parameter, not a margin item.

Is the NSX250F a direct replacement for the new ComPacT range, or is there a SKU mapping required?

The new ComPacT range is the designated successor to the NSX250F, but it is not a direct pin-for-pin or hole-for-hole replacement in all configurations. Mounting dimensions, terminal arrangements, and accessory compatibility may differ between the legacy NSX250F and the new ComPacT equivalents. A formal SKU migration mapping should be obtained from Schneider Electric or an authorized distributor before specifying a new ComPacT unit as a drop-in replacement for an NSX250F in an existing panel.

What certifications does the ComPacT NSX250F carry, and do they cover marine and CCC applications?

The ComPacT NSX250F is compliant with IEC 60947-2 as the international baseline standard, and carries CCC certification for China, EAC certification for post-Soviet states, and marine classification approval for vessel power distribution applications. This compliance breadth enables deployment across EU, Asia-Pacific, marine, and EAC-regulated markets using a single product specification. However, you must verify at the SKU level that the specific variant you are ordering carries the required regional certification — not all trip unit and pole configuration combinations carry every certification.

Why Order Through LeadTime.ca

  • Direct Schneider Electric distributor relationships — enabling access to legacy NSX250F inventory windows and discontinued SKU stock that generic e-commerce channels cannot source
  • Technical staff who understand trip unit selection, compliance verification, and NSX250F-to-new-ComPacT migration — not just order fulfilment
  • Real-time stock verification across North American and international distribution hubs before you commit your BOM
  • Volume pricing and project-specific lead time confirmation available on request
  • Global shipping — LeadTime.ca serves procurement teams and system integrators worldwide, not a single region

At-a-Glance Summary

  • Product: ComPacT NSX250F Molded Case Circuit Breaker — 3-pole, 250A frame, 36 kA breaking capacity at 415VAC
  • Current variants: 200A, 220A, and 250A within the same NSX250F frame
  • Trip unit options: TM-D (thermal-magnetic, general distribution), MA (pure magnetic, motor and VFD circuits), Micrologic 2.2 (electronic, adjustable, selective coordination)
  • Compliance: IEC 60947-2, CCC (China), EAC (post-Soviet states), marine classification
  • Operating temperature: -20 to +60°C
  • Switching capacity: up to 500,000 cycles
  • Lifecycle carbon footprint: 762 kg CO2 equivalent (LV431630 SKU)
  • Discontinuation status: NSX250F line phased out June 2023 — verify LV-series SKU availability before ordering
  • Typical lead time: 2 to 4 weeks if in stock; 6 to 12 weeks for special order of discontinued SKUs
  • New designs: Specify Schneider Electric new ComPacT range for 10-plus year support continuity
  • Key ordering rule: Always specify the complete LV-series catalog number — never order on "NSX250F" frame name alone

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