Skip to main content
Schneider Electric C125N450FM — Miniature Circuit Breakers (MCB)

C125N450FM ComPacT NS circuit breaker, 1250 A, MicroLogic 5.

MPNC125N450FM
Active

Schneider Electric ComPacT NS new generation, C125N450FM, 4P circuit breaker, 1250 A at 50 °C, MicroLogic 5.0 electronic trip unit, 85 kA Icu at 240 V AC, fixed mount, IP40.

$4,992.32Ref. price · indicative, final on quote
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

C125N450FM — Identification
ParameterValue
Product nameComPacT NS new generation
Product rangeComPacT
Product range (series)ComPacT NS630b...1600 new generation
Product/component typeCircuit breaker
Device applicationDistribution
C125N450FM — Ratings
ParameterValue
Rated current (In)1250 A at 50 °C
Breaking capacity85 kA Icu at 220/240 V AC 50/60 Hz conforming to IEC 60947-2 50 kA Icu at 380/415 V AC 50/60 Hz conforming to IEC 60947-2 50 kA Icu at 440 V AC 50/60 Hz conforming to IEC 60947-2 40 kA Icu at 500/525 V AC 50/60 Hz conforming to IEC 60947-2 30 kA Icu at 660/690 V AC 50/60 Hz conforming to IEC 60947-2
Rated service breaking capacity (Ics)50 kA at 220/240 V AC 50/60 Hz conforming to IEC 60947-2 50 kA at 380/415 V AC 50/60 Hz conforming to IEC 60947-2 50 kA at 440 V AC 50/60 Hz conforming to IEC 60947-2 40 kA at 500/525 V AC 50/60 Hz conforming to IEC 60947-2 30 kA at 660/690 V AC 50/60 Hz conforming to IEC 60947-2
Rated operational voltage (Ue)690 V AC 50/60 Hz
Rated insulation voltage (Ui)800 V AC 50/60 Hz conforming to IEC 60947-2
Rated impulse withstand voltage (Uimp)8 kV conforming to IEC 60947-2
Network type (AC/DC)AC
Network frequency50/60 Hz
Utilisation categoryCategory B
Overvoltage categoryIII
C125N450FM — Protection
ParameterValue
Trip unit technologyElectronic
Earth-leakage protectionWithout
Suitability for isolationYes conforming to EN/IEC 60947-2
Electrical durability (cycles)2000 cycles at 690 V In 3000 cycles at 690 V In/2 4000 cycles at 440 V In 5000 cycles at 440 V In/2
Mechanical durability (cycles)10000 cycles
C125N450FM — Mechanical
ParameterValue
Mounting supportBackplate
Mounting modeFixed
Control typeManually operated
Local signalling/indication4 LEDs (red) for fault indication 1 LED (yellow) for overload
C125N450FM — Environmental
ParameterValue
Operating ambient temperature-25...70 °C
Storage ambient temperature-50...85 °C
IP degree of protectionIP40 conforming to IEC 60529
Pollution degree3 conforming to IEC 60947
Relative humidity0...95 %
C125N450FM — Approvals
ParameterValue
StandardsEN/IEC 60947-2
C125N450FM — Specifications
ParameterValue
[Ir] long-time protection pick-up adjustment range0.4...1 x In
Trip unit protection functionsLSI

Product details

It carries a 1250 A rated current at 50 °C and an 85 kA Icu breaking capacity at 240 V AC, with 50 kA Icu at 415 V AC. The MicroLogic 5.0 electronic trip unit provides L (long-time overload), S (short-time short-circuit), and I (instantaneous short-circuit) protection curves. This is a 4-pole, fixed-mount, manually operated unit designed for distribution applications per EN/IEC 60947-2. Mounted on a backplate, front-connected both sides, it occupies 280 mm width by 327 mm height by 147 mm depth.

Fixed-mount on a backplate — this breaker bolts to a panel, not a DIN rail. Front connection on both upside and downside simplifies bus-bar or cable routing in a switchboard. The 70 mm connection pitch matches standard bus-bar spacing for this frame size. IK07 impact resistance handles light mechanical shock. The 44 W power loss at rated current matters for thermal management in a sealed enclosure — factor it into your cooling budget.

Durability and protection features

Mechanical durability is 10,000 cycles; electrical durability ranges from 2,000 cycles at 690 V In to 5,000 cycles at 440 V In/2. For a main breaker that cycles infrequently, this is ample. The MicroLogic 5.0 trip unit includes a 20-minute thermal memory — after a trip, the thermal model retains the heat history so re-closing into a still-hot load does not reset the protection curve, preventing nuisance trips on repeated overloads. Local signalling uses 4 red LEDs for fault indication and 1 yellow LED for overload. No earth-leakage protection built in; if you need ground-fault, you add an external Vigi module or specify a different trip unit.

Frequently asked questions

Where can I buy C125N450FM and what is the lead time?

The C125N450FM is sourced to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — no stock count or lead-time figure is published here.

What is the closest alternative to C125N450FM in the ComPacT family?

Within the same ComPacT NS new generation range, the closest peer by rating is the C125N450FM itself — it is the 1250 A, 4P, MicroLogic 5.0 variant. A different trip unit rating (e.g., 1000 A or 1600 A) or a different breaking capacity code (e.g., S or H instead of N) would change the order code. No pin-compatible drop-in exists with a different rating; the frame size and connection pitch are specific to this ampere class.

What compliance documentation does Schneider provide for C125N450FM?

The breaker is certified to EN/IEC 60947-2. It carries an IP40 rating per IEC 60529 and IK07 per EN 50102. Pollution degree 3 and overvoltage category III are declared per IEC 60947. For RoHS, REACH, and UL documentation, refer to the manufacturer's compliance portal — those declarations are not listed in this evidence set.

MPN
C125N450FM