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Siemens 5SY6405-8 — 4-Pole MCB (DIN Rail)

Siemens 5SY6405-8 SENTRON MCB, 4P, D-curve, 0.5 A, 6 kA

MPN5SY6405-8

Siemens SENTRON 5SY6 series, miniature circuit breaker, 4-pole (4P), D tripping characteristic, 0.5 A rated current, 6 kA (EN 60898) / 30 kA (IEC 60947-2), 400 V AC, IP20.

Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

5SY6405-8 — Identification
ParameterValue
Type / order code5SY6
Brand nameSENTRON
Application suitabilityMechanical engineering / industry
5SY6405-8 — Ratings
ParameterValue
Number of poles4
Pole configuration4P
Rated current (In), AC400 V
Rated current (In), AC0.5 A
Rated voltage, AC (multi-phase)440 V
Rated voltage, AC (single-phase)440 V
Rated voltage, DC (max.)72 V
Voltage typeAC
Rated frequency50/60 Hz
5SY6405-8 — Protection
ParameterValue
Tripping characteristic (trip curve)D
Rated breaking capacity (Icn), per EN 608986 kA
Rated breaking capacity, per IEC 60947-230 kA
Breaking capacity, AC (UL 1077 / CSA C22.2 No.235)5 kA
Overvoltage categoryIII
Degree of protection (IP)IP20, with connected conductors
Neutral conductor switchingNo
Touch protectionYes
5SY6405-8 — Mechanical
ParameterValue
Width in modular units4
Width72 mm
Height90 mm
Depth76 mm
Installation depth70 mm
Mounting positionany
Combined terminal, topYes
Combined terminal, bottomYes
SealableYes
5SY6405-8 — Environmental
ParameterValue
Halogen-freeYes
Silicone-freeYes
Influence of ambient temperature (derating)max. 95% to 55°C, max. 55% to 70°C, max. 35% to 75°C
5SY6405-8 — Performance
ParameterValue
Mechanical service life (switching cycles, typ.)10 000

Product details

Siemens 5SY6405-8 — 4-pole D-curve MCB, 0.5 A, for industrial branch circuits

The Siemens 5SY6405-8 is a SENTRON 5SY6 series miniature circuit breaker with 4 poles (4P), a D tripping characteristic, and a 0.5 A rated current at 400 V AC. The D-curve means it tolerates inrush currents 10–20× rated — typical for motor starters, transformers, or lighting ballasts — without nuisance tripping on startup. At DC, it handles 72 V max with a 15 kA breaking capacity per IEC 60947-2, and under UL 1077 / CSA C22.2 No. 235 it is rated 5 kA at AC.

Mounting and wiring — quick-assembly DIN rail, 4 width units

Sealable, halogen-free, silicon-free. IP20 with connected conductors; touch protection built in.

Overvoltage category III. Humidity influence: max 95% at 55 °C, derating to 55% at 70 °C, 35% at 75 °C. Functional designation per DIN EN 61346-2 and DIN EN 81346-2: letter F. Suitability for mechanical engineering and industrial environments.

Frequently asked questions

Where can I buy 5SY6405-8?

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

What is the breaking capacity of 5SY6405-8?

6 kA per EN 60898, 30 kA per IEC 60947-2 at 400 V AC; 15 kA per IEC 60947-2 at 72 V DC; and 5 kA per UL 1077 / CSA C22.2 No. 235 at AC.

What wire sizes fit the 5SY6405-8 terminals?

Solid and stranded conductors from 0.75 to 35 mm² are accepted at the top and bottom combined terminals.

Will 5SY6405-8 drop into a panel specified for 5SY6602-8?

Both are 4-pole SENTRON 5SY6 breakers with the same 72 mm width and DIN-rail mount, so the footprint matches. The key difference is the tripping characteristic: 5SY6405-8 is D-curve (0.5 A), while 5SY6602-8 is a different curve/rating — verify the branch circuit's inrush requirement before swapping.

MPN
5SY6405-8