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Siemens 5SY5120-6KK11 — 1-Pole MCB (DIN Rail)

Siemens 5SY5120-6KK11 SENTRON MCB, 1P B-20A, 10kA, Railway

MPN5SY5120-6KK11

Siemens SENTRON 5SY5120-6KK11, 1-pole B-curve miniature circuit breaker, 20 A rated current, 10 kA breaking capacity per EN 60898, 15 kA per IEC 60947-2, designed for railway applications.

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

Specifications

5SY5120-6KK11 — Identification
ParameterValue
Product designationMiniature circuit breaker
Brand nameSENTRON
Number of poles1
Pole design1P
Application suitabilityuniversal current
5SY5120-6KK11 — Electrical & Protection
ParameterValue
Tripping characteristic classB
Energy limitation class3
Overvoltage categoryIII
5SY5120-6KK11 — 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
5SY5120-6KK11 — Environmental
ParameterValue
IP protection classIP20, with connected conductors
Pollution degree3
Halogen-freeYes
Silicone-freeYes

Product details

B-curve 20 A — what that means for selectivity

The 5SY5120-6KK11: B-curve trips magnetically at 3–5× In (60–100 A instantaneous). That's fast enough to protect semiconductor loads or long cable runs, but it won't nuisance-trip on motor inrush the way a C-curve might. On a 20 A rail, expect instantaneous trip above 60 A; thermal overload holds the continuous 20 A.

Single modular width (18 mm) — one TE on a DIN rail. Fastens via the quick-assembly system: snap it on, no tools needed. Combined terminal top and bottom accept supply from either end. AC supply can connect to either polarity; DC requires polarity observation. Neutral conductor switching is not integrated — this is a 1-pole breaker for phase-only protection; neutral must be handled separately or via a 2-pole variant. IP20 with connected conductors — panel-internal only, not for wet locations.

Frequently asked questions

Where can I buy 5SY5120-6KK11 and get a price?

This part is sourced and quoted to order against an RFQ through independent distribution. Submit an RFQ for current availability and pricing — confirmed at quote time.

Will 5SY5120-6KK11 drop into a panel specified for 5SY5240-7 without rewiring?

Both are 1-pole SENTRON MCBs in 18 mm width with the same quick-assembly DIN-rail mount. The 5SY5120-6KK11 is a 20 A B-curve; the 5SY5240-7 is a higher-current variant. Physical fit is identical — same footprint, same terminal layout. The deciding factor is the current rating and tripping curve required by your circuit design.

What compliance documentation does Siemens provide for 5SY5120-6KK11?

The part is halogen-free and silicon-free, designed for railway applications with vibration resistance per IEC 60068-2-6. For RoHS, REACH, and UL documentation, request the manufacturer's declaration from your Siemens channel partner — these are standard for SENTRON products.

MPN
5SY5120-6KK11