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Siemens 5SY8305-8 — 3-Pole MCB (DIN Rail)

Siemens 5SY8305-8 SENTRON MCB, 3-Pole D-Curve 0.5A, 70kA

MPN5SY8305-8
Active

Siemens SENTRON 5SY8305-8, 3-pole miniature circuit breaker, D characteristic, 0.5 A at 45 °C, 70 kA IEC breaking capacity, 400 V AC.

Siemens 5SY8305-8 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

5SY8305-8 — Identification
ParameterValue
Brand nameSENTRON
Number of poles3
Suitability for operationMechanical engineering / industry
5SY8305-8 — Protection
ParameterValue
Tripping characteristic (curve)D
Breaking capacity per IEC 60947-270 kA
Overvoltage categoryIII
IP protection classIP20, with connected conductors
Pollution degree3
5SY8305-8 — Electrical
ParameterValue
Rated current (AC)400 V
Rated voltage (AC, multi-phase)440 V
5SY8305-8 — 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
5SY8305-8 — Environmental
ParameterValue
Halogen-freeYes
Silicone-freeYes
Influence of surrounding temperaturemax. 95% to 55°C, max. 55% to 70°C, max. 35% to 75°C

Product details

It's built for 400 V AC systems at 50/60 Hz and carries a 70 kA breaking capacity per IEC 60947-2 — that's the fault level it can safely interrupt without welding contacts or cascading upstream. For UL 1077 / CSA C22.2 No. 235 installations, the interrupting rating is 5 kA.

The 0.5 A rating is temperature-sensitive: at 45 °C it's 0.5 A, at 50 °C it derates to 0.49 A, and at 55 °C to 0.47 A. The 5 kA UL/CSA rating tells you this isn't a primary building breaker in North America — it's a supplementary protector for equipment-level circuits.

Frequently asked questions

What is 5SY8305-8's breaking capacity at 400 V AC?

70 kA per IEC 60947-2 at 400 V AC, 50/60 Hz. For DC circuits the rating is 15 kA per the same standard; under UL 1077 / CSA C22.2 No. 235 it's 5 kA.

What does the D tripping characteristic mean for this MCB?

The D-curve provides magnetic trip between 10× and 20× In (roughly 5 to 10 A for this 0.5 A breaker), making it suitable for loads with high inrush current such as small transformers, solenoid valves, or motor starters where a B- or C-curve would nuisance-trip on startup.

Where can I buy 5SY8305-8 and how is it quoted?

This part is sourced through independent industrial distribution and quoted to order against an RFQ. Availability and current pricing are confirmed at quote time — no stock figures or lead-time numbers are published here.

What compliance documentation is available for 5SY8305-8?

The breaker carries IEC 60947-2 and UL 1077 / CSA C22.2 No. 235 ratings. It is halogen-free and silicon-free. The SENTRON series typically provides CE, UKCA, and EAC declarations; specific RoHS/REACH statements are available from the manufacturer on request.

MPN
5SY8305-8