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Schneider Electric C40N31M320 — Miniature Circuit Breakers (MCB)

Schneider Electric C40N31M320 ComPacT NSX400N, 320 A, 85 kA

MPNC40N31M320
Active

Schneider Electric ComPacT NSX400N, circuit breaker, 3P, 320 A, MicroLogic 1.3 M electronic trip unit, 85 kA Icu at 240 V AC, motor protection.

$709.19Ref. price · indicative, final on quote
Schneider Electric C40N31M320 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

C40N31M320 — Identification
ParameterValue
Product nameComPacT NSX
Product rangeComPacT
Product/component typeCircuit breaker
Device applicationMotor protection
C40N31M320 — Ratings
ParameterValue
Rated current (In)320 A at 65 °C
Poles configuration3P
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 42 kA Icu at 440 V AC 50/60 Hz conforming to IEC 60947-2 30 kA Icu at 500 V AC 50/60 Hz conforming to IEC 60947-2 22 kA Icu at 525 V AC 50/60 Hz conforming to IEC 60947-2 10 kA Icu at 660/690 V AC 50/60 Hz conforming to IEC 60947-2 85 kA Icu at 240 V AC 50/60 Hz conforming to UL 60947-4-1 50 kA Icu at 480 V AC 50/60 Hz conforming to UL 60947-4-1 20 kA Icu at 600 V AC 50/60 Hz conforming to UL 60947-4-1
Rated service breaking capacity (Ics)85 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 42 kA at 440 V AC 50/60 Hz conforming to IEC 60947-2 30 kA at 500 V AC 50/60 Hz conforming to IEC 60947-2 11 kA at 525 V AC 50/60 Hz conforming to IEC 60947-2 10 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
Rated impulse withstand voltage (Uimp)8 kV
Network type (AC/DC)AC
Network frequency50/60 Hz
Utilisation categoryCategory A
Overvoltage categoryIII
C40N31M320 — Protection
ParameterValue
Trip unit technologyElectronic
Earth-leakage protectionWithout
Suitability for isolationYes conforming to EN/IEC 60947-2
Electrical durability (cycles)12000 cycles at 440 V In/2 6000 cycles at 440 V In 6000 cycles at 690 V In/2 3000 cycles at 690 V In
Mechanical durability (cycles)15000 cycles
C40N31M320 — Mechanical
ParameterValue
Mounting supportBackplate
Control typeToggle
Local signalling/indicationFlashing LED (green) for ready to operate
C40N31M320 — 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 60664-1
Relative humidity0...95 %
C40N31M320 — Approvals
ParameterValue
StandardsEN/IEC 60947-2
C40N31M320 — Specifications
ParameterValue
Trip unit protection functionsSI

Product details

Schneider Electric C40N31M320 is a ComPacT NSX400N molded-case circuit breaker, 3-pole, rated 320 A at 65 °C with a MicroLogic 1.3 M electronic trip unit. It's built for motor protection — the 'M' in the trip unit designation means it carries motor-specific curves for starting inrush and overload. Backplate-mounted, front-connected, and toggle-operated, it fits a standard panel layout with 140 mm width and 255 mm height.

At 480 V AC it still holds 50 kA Icu, so it coordinates cleanly with downstream 18 kA or 25 kA rated feeders. The 85 kA at 240 V AC is the high side for 208/240 V distribution. Utilisation category A means it's not intended for frequent switching under load — that's the contactor's job. It's a protection device first.

Trip unit and motor protection

The S curve lets you set a deliberate delay for selectivity with downstream breakers — you can let a branch fault clear before the main trips. The I curve handles the short-circuit instant. Because it's electronic, it holds its calibration over temperature better than a thermal-magnetic unit. Power dissipation is 12.29 W per pole — factor that into your enclosure cooling calculation.

Physical integration

Mounts on a backplate — no DIN rail. Front connections top and bottom, 45 mm connection pitch. Six accessory slots for shunt trips, aux contacts, or communication modules. IP40 enclosure protection, IK07 impact resistance. Horizontal or vertical mounting allowed, flat on the back.

Frequently asked questions

How do I get current pricing and availability for C40N31M320?

The part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm quote.

What is C40N31M320's breaking capacity at 415 V?

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

What compliance documentation does Schneider provide for C40N31M320?

The breaker is certified to EN/IEC 60947-2 and UL 60947-4-1. It carries suitability for isolation per EN/IEC 60947-2. Pollution degree 3 per IEC 60664-1 and overvoltage category III per IEC 60947-2 are documented. Specific RoHS/REACH declarations are available from Schneider Electric's product compliance portal.

MPN
C40N31M320