At 20 A it feeds a 4–5 kW resistive load on a 230 V single-phase circuit. The 18 mm width (1 modular unit) snaps into any standard DIN-rail distribution board, and the 76 mm depth plus 70 mm installation depth fits flush in shallow enclosures. Temperature derating is built in: at 40 °C the breaker is rated 18.78 A, dropping to 16.08 A at 60 °C.
Siemens 5SY4120-6KK11 SENTRON MCB, 1P B-20A, 10/20 kA
MPN5SY4120-6KK11
Siemens SENTRON 5SY4120-6KK11 miniature circuit breaker, 1-pole, B characteristic, 20 A rated current, 10 kA (EN 60898) / 20 kA (IEC 60947-2) breaking capacity, 18 mm width, IP20.
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026
Specifications
| Parameter | Value |
|---|---|
| Product designation | Miniature circuit breaker |
| Brand name | SENTRON |
| Number of poles | 1 |
| Pole design | 1P |
| Application suitability | Mechanical engineering / industry |
| Parameter | Value |
|---|---|
| Tripping characteristic class | B |
| Rated value (EN 60898) | 10 kA |
| Energy limitation class | 3 |
| Overvoltage category | III |
| Parameter | Value |
|---|---|
| Mounting position | any |
| Fastening method | Quick assembly system |
| Combined terminal, top | Yes |
| Combined terminal, bottom | Yes |
| Width | 18 mm |
| Height | 90 mm |
| Depth | 76 mm |
| Installation depth | 70 mm |
| Modular width units | 1 |
| Torque, min. | -40 °C |
| Torque, max. | 75 °C |
| Sealable | Yes |
| Parameter | Value |
|---|---|
| IP protection class | IP20, with connected conductors |
| Pollution degree | 3 |
| Halogen-free | Yes |
| Silicone-free | Yes |
Product details
Frequently asked questions
What is the breaking capacity of 5SY4120-6KK11?
10 kA per EN 60898 and 20 kA per IEC 60947-2. The higher IEC figure applies when the breaker is used in an industrial panel with upstream current-limiting devices.
What compliance documentation does Siemens provide for 5SY4120-6KK11?
The breaker is halogen-free and silicon-free, and carries IP20 protection with connected conductors. It is designed per IEC 81346-2 and DIN EN 61346-2. Standard Siemens declarations of conformity (CE, UKCA) and material compliance (RoHS, REACH) are available on request with the RFQ.
Where can I buy 5SY4120-6KK11 and what is the lead time?
This part is sourced to order against an RFQ through independent distribution channels. Current pricing and lead time are confirmed at quote time — submit an RFQ for a firm commitment.
MPN
5SY4120-6KK11