# Siemens 3SK1211-2BB40 Safety Relay Output Expansion Unit 24V DC

**URL:** https://aio.lv/en/product--siemens-3sk1211-2bb40--1779071
**Data updated:** 2026-05-18 02:40 (EEST)
**Category:** Control Systems
**Manufacturer:** Siemens
**Manufacturer code:** 3SK1211-2BB40
**EAN:** 4011209913783
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 169.49 €
**Prices and availability valid until:** 2026-07-24 23:59
**Price without VAT (21%):** 140.07 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--siemens-3sk1211-2bb40--1779071

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 14.07.2026 | free |
| Pickup points | 17.07.2026 | 1.89 EUR |
| Courier delivery to door | 17.07.2026 | 4.99 EUR |

## Summary description

The Siemens 3SK1211-2BB40 is a safety relay output expansion unit designed for industrial safety applications. Operating at 24V DC, this module provides additional safety-related switching contacts to extend the functionality of safety relay systems. It ensures reliable signal processing and circuit interruption in emergency stop or safety gate monitoring configurations, meeting essential industrial safety standards for machinery and automation control systems.

## Long description

The Siemens 3SK1211-2BB40 is a professional-grade safety relay output expansion unit engineered for demanding industrial safety applications. Operating on a 24V DC power supply, this module serves as a critical component for extending the contact capacity of existing safety relay systems. By providing additional safety-related switching contacts, it facilitates the expansion of complex safety circuits, ensuring that emergency stop signals and safety gate monitoring systems function with high reliability and precision in automated machinery environments.
Advantages
This expansion unit offers a robust solution for increasing the number of safety outputs without requiring a complete redesign of the control architecture. Its design focuses on seamless integration with standard safety relay systems, providing a dependable method to multiply switching contacts for diverse safety functions. The unit is built to meet stringent industrial safety standards, ensuring consistent performance and long-term operational stability in harsh manufacturing conditions. Its compact form factor allows for efficient use of space within control cabinets, while the 24V DC operation ensures compatibility with common industrial control voltage levels.
Suitable for
Emergency stop monitoring systems
Safety gate and protective door monitoring
Industrial automation and machinery control
Expansion of safety-related switching contacts
When it may not be suitable
This unit is not intended for standalone safety control and must be used in conjunction with a primary safety relay or safety controller. It is not suitable for applications requiring AC control voltages or environments that exceed the specified operating temperature and environmental ratings.
Key specifications
Operating voltage: 24V DC
Function: Safety relay output expansion
Contact configuration: 4 NO (Normally Open) and 1 NC (Normally Closed)
Application: Industrial safety and automation
How to use
The device should be installed by qualified personnel within a control cabinet on a standard mounting rail. Connect the input terminals to the output of the primary safety relay to ensure the expansion unit follows the safety logic of the main system. Ensure that all wiring is performed according to the local electrical codes and the manufacturer's technical documentation. Once installed, verify the functionality of the safety circuit by triggering the primary safety device and confirming that all associated outputs respond correctly.
What to consider before purchase
Verify compatibility with your existing safety relay system
Ensure the 24V DC power supply meets the unit's requirements
Check the number of required safety contacts for your specific application
Confirm the installation environment meets the technical specifications
Usage recommendations
Regularly inspect the wiring and terminal connections to ensure they remain secure and free from corrosion. Perform periodic functional tests of the entire safety chain to verify that the expansion unit correctly interrupts the circuit during emergency conditions.

## FAQ

### How much does the Siemens 3SK1211-2BB40 Safety Relay Output Expansion Unit cost, and is it available for purchase?

The price is 169.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 9 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 14.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay, Installment. All transactions are 100% secure and encrypted.

### Can Siemens 3SK1211-2BB40 Safety Relay Output Expansion Unit be purchased with a lease?

Yes, the purchase is available both on credit and with an interest-free installment plan. Learn more about installments and credit options: https://aio.lv/en/payment#b3

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All Siemens products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized Siemens service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

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