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Siemens 5SY5120-6 — 1-Pole MCB (DIN Rail)

Siemens 5SY5120-6 SENTRON MCB, 20A 1P B-Curve, 10kA

MPN5SY5120-6
Active

Siemens SENTRON 5SY5120-6, 1-pole miniature circuit breaker, 20 A rated, B tripping characteristic, 10 kA breaking capacity per IEC/EN 60898-2 and UL1077, 18 mm width.

Siemens 5SY5120-6 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

5SY5120-6 — Identification
ParameterValue
Product designationMiniature circuit breaker
Brand nameSENTRON
Number of poles1
Pole design1P
Application suitabilityuniversal current
5SY5120-6 — Electrical & Protection
ParameterValue
Tripping characteristic classB
Energy limitation class3
Overvoltage categoryIII
5SY5120-6 — 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
5SY5120-6 — Environmental
ParameterValue
IP protection classIP20, with connected conductors
Pollution degree3
Halogen-freeYes
Silicone-freeYes

Product details

That dual-standard listing (IEC + UL) is the authority signal: the part is accepted in both European and North American panels, so a BOM freeze across jurisdictions holds on one order code. Single-pole design (1P) with no neutral switching — it breaks only the line conductor, which is the normal arrangement for a 120/240 V branch circuit where the neutral is bonded elsewhere.

Temperature derating — the real-world current

The 20 A rating holds at 35 °C ambient. Above that, the MCB derates: 18.78 A at 40 °C, 18.14 A at 45 °C, 17.48 A at 50 °C, 16.8 A at 55 °C, and 16.08 A at 60 °C.

Sealable terminals allow the installer to lock the cover after commissioning, meeting some site security requirements.

Frequently asked questions

Where can I buy 5SY5120-6 and how do I get a price?

Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm price and lead time.

Will 5SY5120-6 drop into a panel that was specified around 5SY4116-6CC without rewiring?

Yes — both are 1-pole, 18 mm wide MCBs on the same DIN-rail footprint. The 5SY5120-6 is 20 A B-curve versus the 5SY4116-6CC's 16 A C-curve, so the mechanical fit is identical; only the rating and trip characteristic differ.

What compliance documentation does this brand provide for 5SY5120-6?

The part carries IEC/EN 60898-2 and UL1077 certifications. Housing materials are halogen-free and silicon-free. The manufacturer provides standard declaration of conformity and RoHS/REACH documentation upon request through the supply channel.

MPN
5SY5120-6