The 3SK1211-2BB40: The 5 A contact rating (at 24 V, 115 V, and 230 V) is the same across all three voltage levels — no derating needed when moving between common control voltages. That's unusual and simplifies BOM planning for panels with mixed-voltage safety circuits. The total current through the module must not exceed 12 A, so if you're ganging multiple contacts in series or parallel, watch the package limit. Spring-loaded push-in terminals accept solid wire 1x (20…16 AWG) or 2x (20…16 AWG), and stranded with ferrule 1x (0.5…1.0 mm²) or 2x (0.5…1.0 mm²). No screw torque to check — just strip to 8–10 mm and push. That saves a few minutes per termination on a 20-relay panel. Depth of 121.6 mm is typical for this class — no special clearance needed behind the rail.
Siemens 3SK1211-2BB40 SIRIUS Safety Relay Output Expansion,
MPN3SK1211-2BB40
Active
Siemens SIRIUS safety relay output expansion, 3SK1211-2BB40, 24 VDC coil, 5 A contacts, spring-loaded push-in terminals, 22.5 mm wide, UL.
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026
Specifications
| Parameter | Value |
|---|---|
| Product brand name | SIRIUS |
| Product designation | Output expansion |
| Product design / configuration | Relay enabling circuits |
| Parameter | Value |
|---|---|
| Category (EN ISO 13849-1) | 4 |
| PFHd, high demand rate (EN 62061) | 1.7E-9 1/h |
| Hardware fault tolerance (IEC 61508) | 1 |
| Stop category (EN 60204-1) | 0 |
| Safety device type (IEC 61508-2) | Type A |
| Parameter | Value |
|---|---|
| Safety-related instantaneous contacts | 4 |
| Safety-related delayed contacts | 0 |
| Signaling-function instantaneous contacts | 0 |
| Max. operating frequency | 360 1/h |
| Parameter | Value |
|---|---|
| Rated insulation voltage | 300 V |
| Rated surge voltage withstand | 4 000 V |
| Control supply voltage type (AC/DC) | DC |
| Required output short-circuit protection (fuse / MCB) | gL/gG: 6A or circuit breaker type A: 3A or circuit breaker type B: 2A or circuit breaker type C: 1A |
| Parameter | Value |
|---|---|
| Type of electrical connection | spring-loaded terminal (push-in) |
| Conductor cross-section, solid | 1x (20 ... 16), 2x (20 ... 16) |
| Conductor cross-section, stranded | 1x (20 ... 16), 2x (20 ... 16) |
| Conductor cross-section, with ferrule | 1x (0.5 ... 1.0 mm²), 2x (0.5 ... 1.0 mm²) |
| Plug-in socket connection | No |
| Parameter | Value |
|---|---|
| Touch protection against electric shock | finger-safe |
| Fastening method | screw and snap-on mounting |
| Mounting position | any |
| Width | 22.5 mm |
| Height | 100 mm |
| Depth | 121.6 mm |
| Parameter | Value |
|---|---|
| Operating temperature range | -25 ... +60 °C |
| Storage temperature range | -40 ... +80 °C |
| Relative humidity, operating | 10 ... 95 % |
| Enclosure protection rating (IP) | IP20 |
| Installation altitude, max. | 4 000 m; Derating, see Product Notification 109792701 |
| Shock resistance | 10g / 11 ms |
| Vibration resistance (IEC 60068-2-6) | 5 ... 500 Hz: 0.75 mm |
| Air pressure (SN 31205) | 900 ... 1 060 hPa |
| EMC / emitted interference standards | IEC 60947-5-1, IEC 61000 |
| Parameter | Value |
|---|---|
| UL approval | Yes |
Product details
Frequently asked questions
Where can I buy 3SK1211-2BB40?
This part is sourced and quoted to order through independent distribution. Submit an RFQ for current availability and pricing — no stock or lead-time numbers are published here.
What compliance documentation does Siemens provide for 3SK1211-2BB40?
The part carries UL approval and is designed to EMC standards IEC 60947-5-1 and IEC 61000. The evidence does not list RoHS or REACH declarations, but these are typically available from Siemens for current-production SIRIUS components.
MPN
3SK1211-2BB40