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Siemens 5SY6303-8 — 3-Pole MCB (DIN Rail)

Siemens 5SY6303-8 SENTRON MCB, 3A D-Curve, 3-Pole, 6kA

MPN5SY6303-8

Siemens SENTRON 5SY6 series, miniature circuit breaker, 5SY6303-8, 3 A, D tripping characteristic, 3-pole, 400 V AC, 6 kA breaking capacity per EN 60898, 30 kA per IEC 60947-2, IP20.

$96.02Ref. price · indicative, final on quote
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

5SY6303-8 — Identification
ParameterValue
Design / model code5SY6
Brand nameSENTRON
Number of poles3
Suitability for operationMechanical engineering / industry
5SY6303-8 — Protection
ParameterValue
Tripping characteristic (curve)D
Breaking capacity per EN 608986 kA
Breaking capacity per IEC 60947-230 kA
Overvoltage categoryIII
IP protection classIP20, with connected conductors
5SY6303-8 — Electrical
ParameterValue
Rated current (AC)400 V
Rated voltage (AC, multi-phase)440 V
Rated frequency50/60 Hz
5SY6303-8 — Mechanical
ParameterValue
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
SealableYes
5SY6303-8 — 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

UL 1077 and CSA C22.2 No. 235 listing at 5 kA means it is recognized for supplementary protection in North American panels — not a branch-circuit rated device under UL 489, but accepted downstream of a main breaker. DC rating to IEC 60947-2: 15 kA at 72 V maximum — usable in DC control buses or battery-backed circuits within that voltage ceiling. Temperature derating per the spec: full rating up to 55 °C, then linearly reduced current from 55 °C to 75 °C (95% RH at 55 °C, 55% at 70 °C, 35% at 75 °C). If your enclosure runs hot, you must derate or the breaker may trip thermally below 3 A.

Mechanical fit — snaps onto DIN rail

Mounts via quick assembly system (integral clip) onto 35 mm DIN rail. Occupies 3 width units (54 mm). Depth 76 mm, height 90 mm — clearance for the arc chamber and terminals. Any mounting position allowed. Combined terminal at top and bottom accepts busbar or cable. Sealable cover option (yes) lets you lock the handle position for lockout/tagout compliance.

Frequently asked questions

Who supplies 5SY6303-8 and how is it quoted for volume purchases?

Sourced and quoted to order against an RFQ through independent distribution; availability and current pricing confirmed at quote time.

What is 5SY6303-8's listed depth?

76 mm.

What is 5SY6303-8's listed width?

54 mm.

What compliance documentation does this brand provide for 5SY6303-8?

The part carries IEC 60898, IEC 60947-2, UL 1077, and CSA C22.2 No. 235 listings. Halogen-free and silicon-free construction. RoHS/REACH documentation is standard for SENTRON series products.

MPN
5SY6303-8