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Siemens 5SL1225-6MB — 2-Pole MCB (DIN Rail)

Siemens 5SL1225-6MB SENTRON MCB, 2P, B Curve, 25A, 3kA

MPN5SL1225-6MB

Siemens SENTRON 5SL1225-6MB, miniature circuit breaker, 2-pole, B characteristic, 25 A rated current, 3 kA breaking capacity per IEC 60947-2, 230/400 V AC.

Siemens 5SL1225-6MB datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

5SL1225-6MB — Identification
ParameterValue
Product designationMiniature circuit breaker
Brand nameSENTRON
Application environmentResidential buildings/infrastructure
5SL1225-6MB — Electrical
ParameterValue
Number of poles2
Supply voltage at AC rated value230 V
5SL1225-6MB — Protection
ParameterValue
Tripping characteristic classB
Overvoltage categoryIII
5SL1225-6MB — Mechanical
ParameterValue
Modular width units2
Width36 mm
Height90 mm
Depth76 mm
Installation depth70 mm
Mounting positionany
Min.-40 °C
Max.75 °C
Protection degree (IP)IP20, with connected conductors
5SL1225-6MB — Environmental
ParameterValue
Pollution degree2
5SL1225-6MB — Specifications
ParameterValue
With single-phase operation at AC rated value253 V

Product details

The Siemens 5SL1225-6MB is a SENTRON miniature circuit breaker rated 25 A, B characteristic, 2-pole, with a 3 kA breaking capacity per IEC 60947-2.

Fit and footprint

Mounting position is any, so you can lay it sideways in a shallow enclosure without derating. IP20 with connected conductors, which is normal for a distribution board interior; no washdown rating here. The sealable design lets a panel builder lock the toggle position — useful for a lighting circuit that shouldn't be switched off by accident.

What the ratings mean

The 3 kA breaking capacity (IEC 60947-2) is the maximum prospective fault current this MCB can safely interrupt. At 230/400 V AC, single-phase or multi-phase, this part covers the typical residential and infrastructure branch circuit. Mechanical service life is 4 000 operating cycles typical. That's fine for a distribution board that sees a few operations a year; for a frequently switched load you'd want a contactor ahead of the MCB.

Frequently asked questions

Where can I buy 5SL1225-6MB and get a price?

This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ and we'll respond with a firm quote.

Will 5SL1225-6MB drop into a panel specified around 5SL4363-7?

Not without changes. The 5SL1225-6MB is 2-pole, 36 mm wide; the 5SL4363-7 is 3-pole, 54 mm wide. Both mount on DIN rail at the same 76 mm depth, but the pole count and width are different — you'd need to rework the busbar and possibly the enclosure fill factor.

What is the depth of 5SL1225-6MB?

76 mm overall depth, with a 70 mm installation depth behind the panel surface.

What compliance documentation does Siemens provide for 5SL1225-6MB?

The part carries halogen-free and silicon-free construction, and is rated for overvoltage category III and pollution degree 2 per IEC 60947-2. Standard Siemens SENTRON documentation includes CE declaration of conformity and the product datasheet. RoHS and REACH compliance is typical for this series; the specific declarations are available on request.

MPN
5SL1225-6MB