Schneider NSX400N Circuit Breaker — Specs, Status & Replacement

By Abdullah Zahid
15 min read
Schneider Electric NSX400N 400A molded case circuit breaker, 3-pole bolt-on, industrial panel distribution application

Circuit Breaker Compact NSX400N: Complete Specifications, Discontinued Status, and Replacement Strategy

If you are specifying or sourcing a Schneider NSX400N for a 400A distribution circuit, the first thing you need to know is that the standard configuration — LV432693 with the MicroLogic 2.3 trip unit — was discontinued by Schneider Electric on December 25, 2023. That single fact changes the procurement conversation entirely. Whether you are maintaining an existing panel that uses this molded case circuit breaker or evaluating it for a new build, this guide gives you the technical specifications, the honest discontinuation context, and the replacement strategy you need before committing budget or schedule.

If you have already confirmed the NSX400N is the right part and need to check current stock, view pricing and availability for the Schneider NSX400N at LeadTime.ca — we ship worldwide and can help confirm whether distributor inventory exists before you lock in your project timeline.

Who Should Buy the Schneider NSX400N — and Who Shouldn't

This breaker is the right choice for a specific and narrowing set of buyers. It fits your project if all of the following are true:

  • Your circuit demands exactly 400A at 40°C — not 250A, not 630A — and your short-circuit study confirms available fault current at the breaker location does not exceed 50kA at 415V
  • Your system voltage is 690V AC or lower and operates at 50 or 60 Hz
  • You are retrofitting an existing panel where the 140mm wide, 3-pole bolt-on footprint must match legacy mounting positions and terminal pitch
  • Your trip unit requirement aligns with MicroLogic 2.3 (9 adjustable long-time positions from 160A to 400A) or MicroLogic 5.3 A — and you have confirmed which part number you need
  • You have received dated stock confirmation from a distributor, not a generic availability estimate

If you are designing a new installation and have not yet committed to a part number, specify the Schneider replacement C40N32D400 instead. It is the manufacturer-recommended successor with assured production supply and avoids the supply chain uncertainty that now surrounds residual NSX400N inventory.

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What the Schneider NSX400N Actually Does in Your Panel

The Circuit Breaker Compact NSX400N is a molded case circuit breaker rated at 400A continuous current at 40°C, designed for primary protection and isolation of branch circuits in 690V AC industrial and commercial power distribution panels. It is not a contactor, not a soft starter, and not a fusible switch — it is the device that stands between your feeder and your downstream load, watching for overload conditions using long-time protection, discriminating against motor inrush with short-time protection, and responding to hard faults with instantaneous interruption. When a fault clears or a nuisance condition resolves, its 20-minute thermal memory helps distinguish genuine overload events from transient load spikes before allowing reclosure.

The NSX400N belongs to the Compact NSX product family, which is part of the Schneider EcoStruxure Power architecture. It complies with IEC 60947-2 for low-voltage switchgear and control gear, and carries CCC, EAC, and marine classification approvals, making it deployable in industrial, commercial, infrastructure, and marine environments worldwide without re-certification. The 3-pole version measures 140mm wide by 255mm high by 110mm deep and weighs 6.05 kg — a compact footprint that matters in panel designs where every millimeter of width is allocated. Connection is bolt-on only at a 45mm terminal pitch, meaning this is a fixed, permanent installation device.

Typical System Architecture: Where the NSX400N Sits

The NSX400N occupies the branch protection position in a low-voltage distribution chain — downstream of the main incomer and upstream of the load group it protects. Understanding where it sits helps confirm whether it is the right device for your coordination study.

  • Utility transformer or generator output feeds into the main distribution board through a main incomer or bus-tie breaker rated above 400A
  • The NSX400N is installed as a branch or feeder breaker on a 400A circuit drawn from that main distribution bus
  • Downstream of the NSX400N sit sub-distribution panels, motor control centers, or large individual loads drawing up to 400A continuously
  • The MicroLogic trip unit communicates fault and trip status through built-in signaling outputs (on MicroLogic-equipped variants) to the panel's monitoring or alarm system
  • Adjacent breakers in the same panel frame may include other Compact NSX variants at different current ratings, all coordinated through a short-circuit study that uses the NSX400N's 50kA at 415V breaking capacity as the defining constraint

Typical Applications and Deployment Scenarios

In industrial manufacturing — food processing, beverage production, chemical plants, automotive assembly — the NSX400N appears most often as the branch circuit protector for multi-motor feeder lines or high-load process equipment. Its 9-position adjustable long-time pick-up (160A to 400A) means a single SKU can be configured to match the actual circuit demand rather than forcing panel designers to stock multiple breaker ratings for similar loads.

Commercial HVAC systems and data center power distribution also use the NSX400N where 400A branch circuits feed large air handling units, chiller banks, or uninterruptible power supply systems. The compact 140mm panel footprint matters in these environments, where switchgear real estate is expensive and densely populated.

For retrofit and maintenance applications, the NSX400N remains relevant specifically because existing panels were built around its bolt-on bolt pattern and 45mm terminal pitch. A plant maintenance team replacing a failed unit in a legacy panel often cannot swap in a physically incompatible replacement without modifying the enclosure — which is why residual NSX400N inventory continues to have value even after the December 2023 discontinuation.

The EAC certification also makes it suitable for installations in Eurasian Economic Commission member countries, and marine classification approvals extend its application scope to vessel electrical systems where other MCCB options may not qualify without additional testing.

Application Typical Deployment
Industrial multi-motor feeder protection Branch breaker in MCC or main distribution panel, 400A circuit feeding 3-6 motors or a combined load group
Commercial HVAC distribution Sub-panel branch protection for chiller or AHU feeders in commercial buildings or data centers
Legacy panel retrofit or spare stock Direct replacement for failed NSX400N in existing enclosures where bolt-on mounting and 45mm terminal pitch must be preserved
OEM pre-assembled control cabinets Fixed branch protection integrated into cabinets shipped to end customers; LV432699 (MicroLogic 5.3 A) used when diagnostics output is required
Marine vessel electrical systems Branch circuit protection in shipboard distribution panels where marine classification approval is required
Infrastructure: water and wastewater Pump station distribution panel, protecting 400A feeders to large submersible or horizontal pump motors

Specifications and Variant Comparison

Parameter Value
Rated Current 400A at 40°C
Voltage Rating 690V AC, 50/60 Hz
Breaking Capacity (Icu) 50kA at 415V
Ultimate Breaking Capacity 85kA (at various voltages per datasheet)
Long-time Pick-up Range (MicroLogic 2.3) 9 adjustable positions, 160A to 400A
Thermal Memory 20 minutes before and after tripping
Connection Type Bolt-On terminals, 45mm pitch
Dimensions (3-pole) 140mm W x 255mm H x 110mm D
Net Weight (3-pole) 6.05 kg
Operating Temperature -20°C to +60°C ambient (trip unit calibrated at +40°C)

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

Configuration Part Number Trip Unit Adjustable Settings Status
3-pole with MicroLogic 2.3 LV432693 MicroLogic 2.3 9 positions, 160–400A Discontinued Dec 25, 2023
3-pole with MicroLogic 5.3 A LV432699 MicroLogic 5.3 A Extended diagnostics and communication Limited availability
3-pole without trip unit LV432403 None (thermal-magnetic only) Fixed characteristic Limited availability
4-pole with MicroLogic 2.3 LV432694 MicroLogic 2.3 9 positions, 160–400A Verify with distributor
Replacement model C40N32D400 Verify trip unit type Per specification In production — Schneider recommended successor

If your application requires the MicroLogic 5.3 A with enhanced diagnostics and communication, the LV432699 is the configuration to specify — but confirm stock before committing to a schedule. For new installations where the LV432693 was previously specified, the C40N32D400 is the correct path forward: check current availability and pricing at LeadTime.ca.

Expert Verdict: Should You Still Buy the Schneider NSX400N?

The Circuit Breaker Compact NSX400N earned its place in industrial distribution panels on the strength of a genuinely compact 3-pole footprint, a 9-position adjustable MicroLogic 2.3 trip unit that covers the full 160A to 400A range without field rewiring, and IEC 60947-2 compliance with CCC, EAC, and marine certifications that qualify it for deployment across industries and geographies. For plant maintenance teams replacing a failed unit in an established enclosure — where the 140mm width, 255mm height, and 45mm bolt-on pitch must match exactly — NSX400N residual inventory remains a legitimate and justified purchase, provided you receive a dated stock confirmation before you commit budget. The same applies to OEMs and integrators whose design drawings were locked before the December 2023 discontinuation announcement and who cannot absorb the engineering time to validate a different form-factor replacement mid-project.

Where the NSX400N no longer makes sense is in any new installation or greenfield panel design. The December 25, 2023 end-of-life of LV432693 is not a soft sunset — it is a hard production stop, and residual distributor inventory is depleting. For new builds, Schneider Electric's own recommendation is the C40N32D400, which carries the same current rating with a current production supply chain. If you are evaluating alternatives beyond the Schneider family, the ABB SACE Tmax XT and Eaton EMAX 2 are functionally comparable molded case circuit breakers at the 400A class, but both require verification that bolt-on terminal layout and mounting pitch will accommodate your existing panel frame before substituting — a non-trivial engineering step that should not be skipped to meet a delivery deadline.

The procurement reality with this part is straightforward: do not accept a distributor's verbal assurance that stock exists. Request a dated written lead-time or in-stock confirmation before committing your project schedule to NSX400N availability. Lead times for residual inventory are market-dependent — the brief documents a typical range of 2 to 6 weeks depending on regional warehouse — and that window will only tighten as existing stock depletes. A specialist distributor with active Schneider supply chain relationships can tell you definitively whether the specific pole count and trip unit configuration you need is on a shelf today. Check current NSX400N availability at LeadTime.ca — we source globally and can advise on the C40N32D400 replacement if your required configuration is no longer available.

For volume pricing, project-based quotes, or to confirm lead time before you commit a build schedule, contact the LeadTime.ca team directly — we ship worldwide and work with procurement teams at every stage of the sourcing process.

What Engineers Need to Know Before Ordering the NSX400N

Because there is no active community discussion in public forums — no PLCTalk threads, no Reddit posts in r/PLC or r/automation, no DigiKey Q&A — buyers sourcing the NSX400N do not have the benefit of peer-sourced war stories to learn from. That absence is itself informative: this is a circuit breaker that tends to be specified by electrical engineers and procured by specialist distributors rather than debated in open forums. The decisions that go wrong happen quietly, inside procurement cycles, and they almost always trace back to one of three failure modes that the brief's technical documentation makes clear.

The first and most consequential mistake is ordering LV432693 without confirming its discontinued status. Buyers referencing legacy panel drawings or older specification sheets will still find LV432693 listed as the standard NSX400N. They place the order, procurement commits to a schedule, and the distributor comes back weeks later with no stock and a recommendation to switch to C40N32D400 — a transition that requires engineering review to confirm trip unit compatibility. The fix is to check product lifecycle status at Schneider Electric's official site before any NSX400N order is placed, and to request C40N32D400 as the approved replacement if LV432693 is unavailable.

The second mistake is confusing the two breaking capacity figures. The NSX400N datasheet lists an Icu of 50kA at 415V and an ultimate breaking capacity of 85kA. Buyers who use the 85kA figure in their short-circuit coordination study without understanding that this value applies at different voltages per the datasheet may find their installation under-protected at 415V. Always use the 50kA at 415V Icu value for standard coordination calculations unless your installation voltage differs and the datasheet explicitly provides an alternate figure for that voltage. Conduct a short-circuit study that confirms available fault current at the breaker location does not exceed this rating before finalizing any panel design.

The third recurring specification error is selecting the NSX400N for circuits that draw less than 160A. The MicroLogic 2.3 trip unit's lowest long-time pick-up position is 160A — below that threshold, the trip unit cannot provide proportionate protection. For sub-160A circuits, the correct specification is a lower-rated Compact NSX variant such as the NSX160N or NSX250N. Fitting an NSX400N to a 100A circuit does not add protection headroom; it removes it.

Wiring and Installation Overview

The following is an installation overview for qualified electrical personnel. Full wiring procedures, torque specifications, and commissioning checklists are in the Schneider Electric installation manual for the Compact NSX family — always consult manufacturer documentation before beginning work.

  • Connection is bolt-on only using the 45mm pitch terminal blocks on the top (line) and bottom (load) of the breaker; conductor sizing must be selected per IEC 60947-2 or the applicable national wiring code for the 400A rated current and system voltage
  • Terminal torque values must be confirmed in the Schneider installation manual before tightening — overtorque risks terminal deformation; undertorque creates resistive heating that will degrade connection integrity over time
  • Before installation, confirm your short-circuit study shows available fault current at the installation point does not exceed 50kA at 415V; if it does, a higher-rated breaker or upstream current-limiting protection is required
  • For MicroLogic 2.3 equipped units, set the long-time pick-up dial to the position matching your branch circuit demand (9 positions from 160A to 400A) with the breaker de-energized; document the selected position in your commissioning record
  • If the 4-pole variant (LV432694, 185mm wide) is being installed in a panel originally designed for the 3-pole (140mm wide), verify the additional 45mm of panel width is available before proceeding

Trip Unit Options and Compatible Configurations

The NSX400N is available in three trip unit configurations, each carrying a different part number and delivering a different level of protection and diagnostics capability. Selecting the wrong trip unit type is one of the most common ordering mistakes with this product family.

  • MicroLogic 2.3 (LV432693 — DISCONTINUED; LV432694 for 4-pole): Standard LSI protection — long-time adjustable (9 positions, 160A to 400A), short-time at 6x long-time setting with adjustable delay, instantaneous fixed. Trip signal output included. The most commonly specified configuration for industrial distribution.
  • MicroLogic 5.3 A (LV432699): Enhanced diagnostics and communication features beyond the 2.3 baseline. Preferred when the panel design requires fault data logging, communication output to a monitoring system, or advanced protection coordination documentation. Limited availability — confirm stock before specifying.
  • Without trip unit (LV432403): Fixed thermal-magnetic operation only. No adjustable settings and no trip signal output. Lower cost and simpler design — suitable only where adjustable electronic protection is not required and a fixed characteristic is acceptable.
  • C40N32D400 (Replacement): Schneider Electric's recommended production successor to the discontinued LV432693. Trip unit type must be verified against your specification before substituting — do not assume the replacement replicates the MicroLogic 2.3 configuration without confirming with the distributor or Schneider directly.

Wrong-Part Prevention Checklist

Before placing any NSX400N order, verify every item on this checklist. These are the exact points that generate incorrect orders, project delays, and retrofit complications:

  1. Confirm EXACT breaking capacity required at your location (50kA @ 415V vs. 85kA ultimate — verify short-circuit study)
  2. Verify trip unit presence and type (MicroLogic 2.3 / 5.3 A / none) before ordering — different part numbers
  3. Check pole count: 3-pole (140mm wide) vs. 4-pole (185mm wide) — panel space determines choice
  4. Confirm rated current: NSX400N is 400A only — do NOT substitute 250A, 320A, 630A models from same family
  5. Validate voltage: 690V AC rated — confirm your system matches exactly
  6. Review discontinued status: LV432693 end-of-life Dec 25, 2023 — confirm distributor stock or request replacement C40N32D400
  7. Connection type: Bolt-On fixed only — confirm panel layout accepts bolt terminals

If any item on this checklist cannot be confirmed before your order is placed, contact the LeadTime.ca team — we can help verify part numbers, confirm stock status, and identify the correct replacement configuration before you commit to a purchase.

Frequently Asked Questions

Is the NSX400N (LV432693) still available to order, or is it completely gone?

LV432693 with the MicroLogic 2.3 trip unit was discontinued by Schneider Electric on December 25, 2023, meaning it is no longer manufactured. Some distributors may hold residual stock, but availability is not guaranteed and is depleting. Before specifying LV432693 for any project, request a dated in-stock confirmation from your distributor. If stock is unavailable, Schneider Electric's recommended replacement is C40N32D400 — verify that its trip unit type and form factor match your electrical design drawing before accepting it as a substitute.

What is the difference between the 50kA and 85kA breaking capacity figures on the NSX400N datasheet?

The NSX400N carries an Icu (rated ultimate short-circuit breaking capacity) of 50kA at 415V and an 85kA value that applies at different system voltages as documented in the Schneider datasheet. For standard protection coordination at 415V AC, use the 50kA figure. Using the 85kA figure in a 415V coordination study risks under-protecting your installation if available fault current exceeds 50kA at that voltage. Always conduct a short-circuit study and confirm Isc at the breaker location does not exceed the Icu rating for your specific system voltage.

Can the MicroLogic 2.3 trip unit be adjusted to protect a circuit drawing only 200A, even though the breaker is rated 400A?

Yes — the MicroLogic 2.3 long-time pick-up dial supports 9 positions from 160A to 400A, so a 200A circuit can be accommodated by selecting the appropriate position (approximately position 3, corresponding to 224A). However, the minimum pick-up is 160A, meaning circuits drawing less than 160A cannot be adequately protected by the NSX400N with this trip unit. For sub-160A circuits, specify a lower-rated Compact NSX variant.

Is the 4-pole NSX400N a direct swap for the 3-pole in an existing panel?

No. The 4-pole variant (LV432694) is 185mm wide compared to the 3-pole's 140mm width, a difference of 45mm. Installing the 4-pole in a panel slot sized for a 3-pole requires verifying that the additional panel width is physically available and that the bus bar or terminal connections accommodate a fourth pole. Never assume dimensional interchangeability between pole configurations — measure the available panel space and confirm terminal layout before ordering the 4-pole variant.

What happens if the NSX400N trips on an overload — does it require manual reset or can it reclose automatically?

The NSX400N requires manual lever operation to reset and reclose after a trip — it does not automatically reclose. The 20-minute thermal memory built into the MicroLogic trip unit retains heat state information both before and after a trip event, meaning the unit will account for accumulated thermal stress when evaluating conditions for reclosure. Allow sufficient cooling time before attempting to reset after a thermal overload trip to avoid immediate re-tripping on residual heat.

How do I confirm the C40N32D400 is a valid replacement for LV432693 in my existing panel?

Confirm three things with your Schneider distributor or Schneider technical support: that the C40N32D400 matches the 400A current rating and 690V AC voltage rating of LV432693; that the trip unit type is equivalent or compatible with the protection scheme documented in your electrical design drawings; and that the physical form factor — specifically the bolt-on terminal pitch and pole width — accommodates your panel's existing mounting provisions. Do not assume dimensional or functional equivalence without written confirmation from Schneider Electric or an authorized technical representative.

Why Order From LeadTime.ca

  • LeadTime.ca ships worldwide — Canadian, US, and international procurement teams can source through a single point of contact without navigating regional distributor boundaries
  • We specialize in industrial automation and power distribution components, including legacy and transitional inventory of discontinued products like the NSX400N
  • Our team can confirm stock status, provide lead-time quotes, and identify approved replacement options — including C40N32D400 — before you commit project budget or schedule
  • Volume pricing and project-based quotes are available; contact us directly for orders requiring multiple units or phased delivery
  • We source hard-to-find parts through active distributor relationships — if residual NSX400N inventory exists in the supply chain, we will find it

At-a-Glance Summary

  • Schneider NSX400N is a 400A, 690V AC molded case circuit breaker in the Compact NSX family, rated Icu 50kA at 415V
  • Standard 3-pole configuration (LV432693 with MicroLogic 2.3) was discontinued December 25, 2023 — residual stock only
  • Schneider Electric recommended replacement: C40N32D400 — verify trip unit type and form factor before substituting
  • MicroLogic 2.3 trip unit offers 9 adjustable long-time pick-up positions from 160A to 400A without field rewiring
  • 3-pole footprint: 140mm W x 255mm H x 110mm D, 6.05 kg — 4-pole variant (LV432694) measures 185mm wide
  • Bolt-on terminal connection at 45mm pitch — fixed installation only, not sliding or plug-in
  • Thermal memory: 20 minutes before and after tripping, supporting nuisance-trip discrimination during load recovery
  • Certifications: IEC 60947-2, CCC, EAC, marine — qualifies for industrial, commercial, infrastructure, and marine deployment globally
  • LV432699 (MicroLogic 5.3 A) and LV432403 (no trip unit) remain in limited availability — confirm stock before specifying
  • Wrong-part risks: breaking capacity figure confusion (50kA vs. 85kA at different voltages), pole count mismatch, and ordering discontinued LV432693 without stock confirmation are the three most critical errors to prevent

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