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Siemens 5SY8308-8 — 3-Pole MCB (DIN Rail)

Siemens 5SY8308-8 SENTRON MCB, D-curve 8A 3P 40kA

MPN5SY8308-8
Active

Siemens SENTRON 5SY8308-8, 3-pole miniature circuit breaker, D tripping characteristic, 8 A rated current, 40 kA breaking capacity at 440 V AC.

Siemens 5SY8308-8 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

5SY8308-8 — Identification
ParameterValue
Brand nameSENTRON
Number of poles3
Pole configuration3P
Suitability for operationMechanical engineering / industry
5SY8308-8 — Protection
ParameterValue
Tripping characteristic (curve)D
Breaking capacity per IEC 60947-240 kA
Overvoltage categoryIII
IP protection classIP20, with connected conductors
Pollution degree3
5SY8308-8 — 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
5SY8308-8 — 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
5SY8308-8 — 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

Siemens 5SY8308-8 — D-curve MCB for motor and transformer branch protection

The 8 A rating holds at 45 °C ambient; at 50 °C it derates to 7.75 A, and at 55 °C to 7.5 A — factor that into the panel thermal budget if the enclosure runs warm.

Fastening is via the quick-assembly system — snaps onto the rail without tools.

DC and AC ratings

On DC circuits the breaking capacity is 15 kA at up to 72 V (per IEC 60947-2). The supply frequency is 50/60 Hz. The part is halogen-free and silicon-free, sealable, and suitable for mechanical engineering and industry environments.

Frequently asked questions

Will 5SY8308-8 drop into a panel specified around 5SY4310-7CV without rewiring?

No — the 5SY4310-7CV is single-pole; the 5SY8308-8 is 3-pole. The footprint, wiring, and circuit configuration are different.

Where can I buy 5SY8308-8?

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

MPN
5SY8308-8