Siemens · 3SB2 Series

3SB2-210-0AB01

Active
CE

3SB2 30mm Green Flush Button Legacy

Siemens 3SB2 Series Introduced circa 1990

Siemens 3SB2 legacy 30mm push button — predecessor to SIRIUS ACT.

Common Applications

Legacy Siemens 30mm button found on older German/European machinery from 1990-2013. Replaced by the 22mm SIRIUS ACT 3SU1 series. Still available for legacy replacement. If you see 3SB on a Siemens panel, these are the buttons.

Compatibility

Legacy 30mm — not compatible with 22mm SIRIUS ACT. For new builds, migrate to 3SU1 (22mm). 30mm cutout requires adapter plate for 22mm replacement.

Specifications

Actuator Type
Flush
Certifications
CE
Color
Green
Cutout Diameter
30mm
Material
Metal

Installation Quick Reference

Panel cutout: 30mm. Insert from the front of the panel, secure with mounting nut from behind (tighten to 2-3 Nm).

Contact block: Snap or screw the contact block onto the rear of the button body. Ensure the contact block orientation matches the wiring diagram — NO terminals are usually marked.

Wiring: Use 0.5-2.5mm² stranded wire with ferrules. Tighten screw terminals to 0.8 Nm. Test the button function before energizing the circuit.

Dimensions

Front 30mm cutout panel hole diameter Side panel contact ~45mm depth

Troubleshooting

Button doesn't respond when pressed

Check the contact block first — it's the most common failure point. Test continuity across the NO or NC terminals with a multimeter. If no click is felt, the return spring in the head may be broken.

Works intermittently

Contact block contacts are pitted or burned. Replace the contact block — don't try to file the contacts. Check if the rated cycle count has been exceeded.

Button feels mushy or doesn't click

The spring return mechanism in the button head is worn. Replace the head. The contact block can usually be reused if it tests OK.

Where to Buy

Price range

$3.02 — $51.07

across 2 distributors

Quick Specs

Actuator Type
Flush
Certifications
CE
Color
Green
Cutout Diameter
30mm
Material
Metal

What People Are Saying

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“Legacy Siemens 30mm button found on older German/European machinery from 1990-2013. Replaced by the 22mm SIRIUS ACT 3SU1 series. Still available for legacy replacement. If you see 3SB on a Siemens pan”

Reddit r/PLC 48 upvotes View thread →