3SE2120-1UW
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Siemens 3SE2 Series
843 variants · Siemens
Siemens 3SE2 — SIRIUS Position Switch for General Limit and Presence Detection
The Siemens 3SE2 series is a general-purpose position switch (limit switch) with over 840 variants, providing reliable detection of mechanical position, presence, and end-of-travel in industrial automation, material handling, and machine tool applications. Unlike the safety-rated 3SE5 series, the 3SE2 is designed for control and signaling functions rather than safety interlocking.
Position Switch vs Proximity Sensor
A mechanical position switch uses physical contact with the target object through a plunger, roller lever, or rod actuator — providing positive mechanical operation with visible actuation. An inductive or capacitive proximity sensor detects the target without contact. Choose position switches when mechanical reliability and visual confirmation of actuation are required; choose proximity sensors when non-contact sensing is needed (high-speed, dirty environments, small targets).
Actuator Options
- Plunger: Short stroke, direct axial actuation. For end-of-travel detection on linear slides.
- Roller Plunger: Plunger with roller for angled approach by cam or moving ramp.
- Roller Lever: Rotary actuation with adjustable lever length. For cam-operated sequencing.
- Rod / Spring Rod: Long flexible actuator for irregular targets or wide sensing area.
Availability
3SE2 position switches: broadly stocked at Siemens distributors. Wide range of actuator heads, contact blocks, and connector options.
About the Siemens 3SE2 Series
The Siemens 3SE2 Series series groups 843 related part numbers, each listed with full specifications, a datasheet where available, and an RFQ option. Variants differ by circuit principle, temp operating max and temp operating min, so you can match the exact circuit principle your application requires using the selection guide below.
Select a variant by
- Circuit principle
- slow-action contacts · snap-action contacts
- Temp operating max
- 80 °C · 85 °C
- Temp operating min
- -30 °C · -25 °C
- Cable entry type
- M20 x 1.5 · M25 x 1.5
- Depth
- 221 mm · 265 mm · 267 mm
- Height
- 68 mm · 138 mm · 140 mm
- Width
- 156 mm · 193 mm · 284 mm
Variant comparison
| Parameter | 3SE2932-0AA20 | 3SE2912-2AA20 | 3SE2932-1AB20 | 3SE2 120-6XX | 3SE2100-0C | 3SE2100-0D |
|---|---|---|---|---|---|---|
| Circuit principle | — | — | — | — | slow-action contacts | slow-action contacts |
| Temp operating max | 80 °C | 80 °C | 80 °C | 85 °C | — | — |
| Temp operating min | -25 °C | -25 °C | -25 °C | -30 °C | — | — |
| Cable entry type | M25 x 1.5 | M20 x 1.5 | M25 x 1.5 | — | — | — |
| Depth | 267 mm | 265 mm | 221 mm | — | — | — |
| Height | 140 mm | 138 mm | 68 mm | — | — | — |
| Width | 284 mm | 156 mm | 193 mm | — | — | — |
Request a quote on any Siemens 3SE2 Series part number and we confirm price, availability and lead time per line — including end-of-life and allocation-constrained variants.
