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Schneider Electric C125H420FM — Miniature Circuit Breakers (MCB)

Schneider Electric C125H420FM ComPacT NS, 1250 A, 85 kA Icu

MPNC125H420FM
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Schneider Electric ComPacT NS new generation, C125H420FM, 4P 1250 A circuit breaker, MicroLogic 2.0 electronic trip unit, 85 kA Icu at 240 V AC, fixed mount.

Schneider Electric C125H420FM datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

C125H420FM — Identification
ParameterValue
Product nameComPacT NS new generation
Product rangeComPacT
Product range (series)ComPacT NS630b...1600 new generation
Product/component typeCircuit breaker
Device applicationDistribution
C125H420FM — 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 70 kA Icu at 380/415 V AC 50/60 Hz conforming to IEC 60947-2 65 kA Icu at 440 V AC 50/60 Hz conforming to IEC 60947-2 50 kA Icu at 500/525 V AC 50/60 Hz conforming to IEC 60947-2 42 kA Icu at 660/690 V AC 50/60 Hz conforming to IEC 60947-2
Rated service breaking capacity (Ics)52 kA at 220/240 V AC 50/60 Hz conforming to IEC 60947-2 52 kA at 380/415 V AC 50/60 Hz conforming to IEC 60947-2 48 kA at 440 V AC 50/60 Hz conforming to IEC 60947-2 37 kA at 500/525 V AC 50/60 Hz conforming to IEC 60947-2 31 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
C125H420FM — 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
C125H420FM — Mechanical
ParameterValue
Mounting supportBackplate
Mounting modeFixed
Control typeManually operated
Local signalling/indication4 LEDs (red) for fault indication 1 LED (yellow) for overload
C125H420FM — 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 %
C125H420FM — Approvals
ParameterValue
StandardsEN/IEC 60947-2
C125H420FM — Specifications
ParameterValue
[Ir] long-time protection pick-up adjustment range0.4...1 x In
Trip unit protection functionsLI

Product details

The C125H420FM is a 4-pole, 1250 A fixed-mount circuit breaker from the ComPacT NS new generation range, built for distribution duty in industrial and commercial switchboards. Its MicroLogic 2.0 electronic trip unit provides L (long-time overload) and I (instantaneous short-circuit) protection, with a 20-minute thermal memory that prevents nuisance reclosing on a hot breaker after a fault clears.

Fixed-mount on a backplate, with front-front connections (upside and downside both front) and a 70 mm connection pitch — standard for panel builder layouts where busbar and cable entry are on the same face.

Durability and electrical life

Electrical durability depends on load: 2,000 cycles at full rated current (1250 A) at 690 V, 3,000 cycles at half current at 690 V, and up to 5,000 cycles at half current at 440 V. For a distribution breaker that's not cycled daily, that's a long service life — but if your application involves frequent switching (like a capacitor bank or welding line), factor the electrical endurance curve into your maintenance schedule.

Frequently asked questions

Where can I buy C125H420FM and how do I get a price?

The C125H420FM is sourced to order against an RFQ through independent distribution. Submit a request for quote (RFQ) to confirm current availability and pricing — no stock or price figures are published here.

What is C125H420FM's breaking capacity at 415 V?

The C125H420FM is rated 70 kA Icu at 380/415 V AC 50/60 Hz per IEC 60947-2, which is the H breaking capacity code.

What compliance documentation does Schneider provide for C125H420FM?

The C125H420FM is designed and tested to EN/IEC 60947-2, with pollution degree 3 and overvoltage category III. Schneider Electric provides the standard IEC declaration of conformity and test certificates for the ComPacT NS new generation range. RoHS and REACH compliance documentation is available from Schneider's product support portal.

MPN
C125H420FM