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Siemens 5SY8305-8 — Miniature Circuit Breakers (MCB)

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)
Source DocumentedChannel stated on listing & quote
Condition PhotosReal unit photos / video on request
WhatsApp AnswersFast human replies for machine-down parts
Worldwide DispatchDHL/FedEx — transit quoted per order
Independent China distributor & sourcing agent· Listing updated Sep 2026

Specifications

5SY8305-8 — Ratings
ParameterValue
Overvoltage categoryIII
5SY8305-8 — Mechanical
ParameterValue
Width54 mm
Height90 mm
Depth76 mm

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