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Siemens 5SY4103-8 — 1-Pole MCB (DIN Rail)

Siemens 5SY4103-8 SENTRON MCB, 1P D-curve, 10 kA, 400 V AC

MPN5SY4103-8
Active

Siemens SENTRON 5SY4103-8, 1-pole miniature circuit breaker, D tripping characteristic, 10 kA per EN 60898, 35 kA per IEC 60947-2, 400 V AC, 1 MW width.

$30.48 – $69.48Ref. price · indicative, final on quote
Siemens 5SY4103-8 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

5SY4103-8 — Identification
ParameterValue
Product designationMiniature circuit breaker
Brand nameSENTRON
Number of poles1
Pole design1P
Application suitabilityMechanical engineering / industry
5SY4103-8 — Electrical & Protection
ParameterValue
Tripping characteristic classD
Overvoltage categoryIII
5SY4103-8 — Mounting & Connection
ParameterValue
Mounting positionany
Fastening methodQuick assembly system
Combined terminal, topYes
Combined terminal, bottomYes
Width18 mm
Height90 mm
Depth76 mm
Installation depth70 mm
Modular width units1
Torque, min.-40 °C
Torque, max.75 °C
SealableYes
5SY4103-8 — Environmental
ParameterValue
IP protection classIP20, with connected conductors
Pollution degree3
Halogen-freeYes
Silicone-freeYes

Product details

That D-curve means it's built for loads with high inrush — motor starters, transformers, welding equipment — where the magnetic trip holds off until roughly 10–20× rated current before instantaneously opening. It's a standard DIN-rail unit, 18 mm wide (1 modular width), and mounts in any position.

Breaking capacity and standards — what the ratings mean

This breaker carries three breaking-capacity ratings depending on the standard applied. For UL 1077 and CSA C22.2 No. 235 the rating is 5 kA at 400 V AC — relevant if the panel is destined for North American markets. On DC circuits (up to 72 V) it's rated 15 kA per IEC 60947-2. The D-curve's magnetic trip threshold is higher than B or C curves, so it won't nuisance-trip on the inrush of a 3-phase motor or a bank of discharge lamps.

Vibration resistance per IEC 60068-2-6 covers typical industrial panel conditions.

Frequently asked questions

Who supplies 5SY4103-8 and how is it quoted for volume purchases?

The 5SY4103-8 is sourced through independent distribution and quoted to order against an RFQ. Availability and current pricing are confirmed at quote time; no stock or price figures are published here.

Will 5SY4103-8 drop into a panel that was specified around 5SY4140-7 without rewiring?

Both are 1-pole SENTRON MCBs on the same 18 mm DIN-rail footprint, so the mechanical fit is identical. The difference is the tripping characteristic: 5SY4103-8 is a D-curve (high inrush), while 5SY4140-7 is a different curve. If the panel's load type matches the D-curve, it's a direct swap; if the original design called for a B or C curve, the D-curve may not provide adequate protection for low-inrush circuits.

What compliance documentation does this brand provide for 5SY4103-8?

The breaker is certified to IEC / EN 60898-1, IEC / EN 60947-2, and UL 1077 / CSA C22.2 No. 235. It is halogen-free and silicon-free. The manufacturer provides a declaration of conformity and test reports covering these standards; RoHS and REACH compliance documentation is available on request.

MPN
5SY4103-8