Schneider Electric Compact NSX Modules: NSX400N Fixed Circuit Breaker

Technical Dossier

Product Details And Specifications

Schneider Electric Compact NSX Series Technical Notes

The Schneider Electric Compact NSX series is one of the most widely deployed molded case circuit breaker (MCCB) platforms in global heavy industry. Rated from 16 A to 630 A, the NSX range is installed across petrochemical complexes, nuclear auxiliary power distribution panels, offshore oil platforms, and large-scale refinery motor control centers (MCCs). Its IEC 60947-2 compliance and high short-circuit breaking capacity (up to 150 kA at 415 V for the H-frame) make it the reference standard for critical power distribution in environments where nuisance tripping and arc flash risk must be minimized. The NSX400N (400 A, N-frame, 50 kA Icu at 415 V AC) is a fixed-mount variant widely specified in main distribution boards and sub-distribution panels across these sectors.

The Evolution of Compact NSX Architecture

The Compact NSX platform succeeded the earlier Compact NS series (introduced in the 1990s), which itself replaced the legacy Compact C range. The NS-to-NSX transition, completed by approximately 2007–2010, introduced a redesigned thermal-magnetic and electronic trip unit interface, improved arc-flash containment geometry, and a standardized accessory rail system compatible with Micrologic trip units (A, E, P, H variants). The NSX frame is segmented into four current classes: NSX100 (up to 100 A), NSX160/250 (up to 250 A), NSX400/630 (up to 630 A). Each frame class shares a common accessory ecosystem — auxiliary contacts, shunt trips, undervoltage releases, and rotary handles — ensuring backward compatibility within the same frame size. The breaking capacity suffix designates the Icu rating: F (36 kA), N (50 kA), H (70 kA), S (100 kA), L (150 kA). As of 2024, the Compact NSX series remains in active production, though select accessories and trip unit variants have been consolidated or superseded by Micrologic 6.0 and 7.0 firmware generations.

Compact NSX Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked models across the Compact NSX range. Models are classified by frame, function, and trip unit type.

Fixed Circuit Breakers — NSX400 Frame (400 A)

• NSX400N: 400 A fixed MCCB, N-frame, 50 kA Icu @ 415 V, 3P, thermal-magnetic TM400D trip unit.
• NSX400F: 400 A fixed MCCB, F-frame, 36 kA Icu @ 415 V, 3P, standard distribution duty.
• NSX400H: 400 A fixed MCCB, H-frame, 70 kA Icu @ 415 V, 3P, high short-circuit environments.
• NSX400S: 400 A fixed MCCB, S-frame, 100 kA Icu @ 415 V, 3P, industrial switchgear panels.

Withdrawable Circuit Breakers — NSX400 Frame

• NSX400NA: 400 A withdrawable MCCB, N-frame, plug-in chassis, Micrologic 2.3 trip unit.
• NSX400HA: 400 A withdrawable MCCB, H-frame, plug-in chassis, Micrologic 5.3 E trip unit.

Fixed Circuit Breakers — NSX630 Frame (630 A)

• NSX630N: 630 A fixed MCCB, N-frame, 50 kA Icu @ 415 V, 3P, TM630D trip unit.
• NSX630F: 630 A fixed MCCB, F-frame, 36 kA Icu @ 415 V, 3P, feeder protection.
• NSX630H: 630 A fixed MCCB, H-frame, 70 kA Icu @ 415 V, 3P, motor protection duty.
• NSX630S: 630 A fixed MCCB, S-frame, 100 kA Icu @ 415 V, 3P, high-fault-level distribution.

Fixed Circuit Breakers — NSX100/160/250 Frame

• NSX100F: 100 A fixed MCCB, F-frame, 36 kA Icu @ 415 V, 3P, branch circuit protection.
• NSX100N: 100 A fixed MCCB, N-frame, 50 kA Icu @ 415 V, 3P, standard industrial feeder.
• NSX160N: 160 A fixed MCCB, N-frame, 50 kA Icu @ 415 V, 3P, sub-distribution panels.
• NSX250N: 250 A fixed MCCB, N-frame, 50 kA Icu @ 415 V, 3P, MCC incomer duty.
• NSX250H: 250 A fixed MCCB, H-frame, 70 kA Icu @ 415 V, 3P, high-fault-level feeders.
• NSX160H: 160 A fixed MCCB, H-frame, 70 kA Icu @ 415 V, 3P, motor starter panels.
• NSX100H: 100 A fixed MCCB, H-frame, 70 kA Icu @ 415 V, 3P, critical branch circuits.