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Siemens 5SY8125-7 — 1-Pole MCB (DIN Rail)

Siemens 5SY8125-7 SENTRON MCB, 1P C-Char, 30 kA IEC, 18 mm

MPN5SY8125-7
Active

Siemens SENTRON 5SY8125-7 miniature circuit breaker, 1-pole, C characteristic, 30 kA at 400 V AC per IEC 60947-2, 18 mm width, 76 mm depth.

Siemens 5SY8125-7 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

5SY8125-7 — Identification
ParameterValue
Product designationMiniature circuit breaker
Brand nameSENTRON
Number of poles1
Pole design1P
Application suitabilityMechanical engineering / industry
5SY8125-7 — Electrical & Protection
ParameterValue
Tripping characteristic classC
Overvoltage categoryIII
5SY8125-7 — 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
5SY8125-7 — Environmental
ParameterValue
IP protection classIP20, with connected conductors
Pollution degree3
Halogen-freeYes
Silicone-freeYes

Product details

Siemens 5SY8125-7 — 1-pole C-characteristic MCB, 30 kA breaking capacity

The Siemens 5SY8125-7 is a 1-pole miniature circuit breaker from the SENTRON series, with a C tripping characteristic and a rated breaking capacity of 30 kA at 400 V AC per IEC 60947-2. On the DC side, it's rated 15 kA at 60 V per IEC 60947-2, and under UL 1077 it carries 5 kA — so if you're specifying for a North American panel under UL 508A, that 5 kA SCCR is the number that governs the branch-circuit coordination study.

Environmental and installation notes

Rated for ambient temperatures from -40 °C to 75 °C, with humidity derating: max 95% RH at 55 °C, tapering to 35% at 75 °C. Vibration resistance per IEC 60068-2-6: ±1 mm at 5–25 Hz, 50 m/s² at 25–150 Hz.

Frequently asked questions

What is the breaking capacity of the 5SY8125-7?

30 kA at 400 V AC per IEC 60947-2, 15 kA at 60 V DC per IEC 60947-2, and 5 kA per UL 1077. The 30 kA AC rating is the headline figure for high-fault industrial panels.

What is the width and depth of the 5SY8125-7?

Width is 18 mm (1 modular unit), depth is 76 mm, height is 90 mm. It mounts on standard DIN rail in any position.

Where can I buy the 5SY8125-7?

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

Does the 5SY8125-7 comply with UL and IEC standards?

Yes, it is certified to IEC / EN 60947-2 and UL 1077. The UL 1077 rating is 5 kA, which governs North American branch-circuit coordination.

MPN
5SY8125-7