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Siemens 5SY4308-8 — 3-Pole MCB (DIN Rail)

Siemens 5SY4308-8 SENTRON 3-Pole MCB, D-Curve, 10 kA

MPN5SY4308-8
Active

Siemens SENTRON 5SY4308-8, 3-pole miniature circuit breaker, D tripping characteristic, 10 kA interrupting capacity per EN 60898, 20 kA per IEC 60947-2, 3 modular width units.

$239.63Ref. price · indicative, final on quote
Siemens 5SY4308-8 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

5SY4308-8 — Identification
ParameterValue
Brand nameSENTRON
Number of poles3
Pole configuration3P
Suitability for operationMechanical engineering / industry
5SY4308-8 — Protection
ParameterValue
Tripping characteristic (curve)D
Breaking capacity per EN 6089810 kA
Breaking capacity per IEC 60947-220 kA
Overvoltage categoryIII
IP protection classIP20, with connected conductors
Pollution degree3
5SY4308-8 — Electrical
ParameterValue
Rated voltage (AC, multi-phase)440 V
Voltage type (AC/DC)AC
Supply frequency range50/60 Hz
Power loss per pole at rated current (AC, hot)0.8 W
Mechanical service life (operating cycles, typ.)10 000
Neutral conductor switchingNo
Rated voltage (AC, single-phase)440 V
5SY4308-8 — Mechanical
ParameterValue
Modular width units3
Mounting positionany
Width54 mm
Height90 mm
Depth76 mm
Installation depth70 mm
Terminal tightening torque, max.75 °C
Terminal tightening torque, min.-40 °C
Combined terminal, topYes
Combined terminal, bottomYes
Fastening methodQuick assembly system
SealableYes
Accepts supplementary devicesYes
5SY4308-8 — Environmental
ParameterValue
Halogen-freeYes
Silicone-freeYes
Influence of surrounding temperaturemax. 95% to 55°C, max. 55% to 70°C, max. 35% to 75°C
Vibration resistance (IEC 60068-2-6)±1mm at 5 to 25Hz; 50m/s² at 25 to 150Hz

Product details

D-curve for high-inrush loads

The 5SY4308-8: Rated for 3-pole operation at 400 V AC (440 V max under multi-phase or single-phase operation) and 60 V DC (72 V max), this SENTRON MCB covers the common 3-phase panel voltages across Europe and North American industrial installations.

Frequently asked questions

What is the difference between a B-curve and D-curve MCB like the 5SY4308-8?

The D curve (10–20× In) trips magnetically at a much higher multiple of rated current than a B curve (3–5× In) or C curve (5–10× In).

Can the 5SY4308-8 be used for 3-phase motor protection?

Yes — the D tripping characteristic and 20 kA interrupting capacity per IEC 60947-2 make it appropriate for motor branch-circuit protection in industrial panels, provided the motor full-load current and starting surge are within the breaker's thermal-magnetic curve. Verify coordination with the upstream short-circuit protective device.

MPN
5SY4308-8