# Siemens 3RH1921-2CA01 Auxiliary Switch Block, 1 NC Contact

**URL:** https://aio.lv/en/product--siemens-3rh1921-2ca01--12455728
**Data updated:** 2026-05-18 09:33 (EEST)
**Category:** Printer & Copier Parts
**Manufacturer:** Siemens
**Manufacturer code:** 3RH1921-2CA01
**EAN:** 4011209281363
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 7.49 €
**Prices and availability valid until:** 2026-07-18 23:59
**Price without VAT (21%):** 6.19 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--siemens-3rh1921-2ca01--12455728

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 13.07.2026 | free |
| Pickup points | 16.07.2026 | 1.99 EUR |
| Courier delivery to door | 16.07.2026 | 4.99 EUR |

## Summary description

The Siemens 3RH1921-2CA01 is a high-quality auxiliary switch block featuring 1 normally closed (NC) contact. Designed for reliable integration with contactors and control relays, this component ensures precise switching operations in industrial automation and electrical control systems. It provides robust performance and easy installation for professional electrical engineering applications.

## Long description

The Siemens 3RH1921-2CA01 is a professional-grade auxiliary switch block designed to expand the switching capabilities of SIRIUS contactors and control relays. Featuring one normally closed (NC) contact, this component is engineered for seamless integration into industrial control circuits, ensuring reliable signal transmission and precise operational feedback. Its robust construction and compatibility with various contactor sizes make it an essential element for complex electrical automation systems.
Advantages
This auxiliary switch block offers significant flexibility through its tool-free mounting design, allowing for rapid installation on compatible contactors. The use of spring-type terminals ensures a secure and vibration-resistant connection, which is critical for maintaining signal integrity in demanding industrial environments. As part of the modular SIRIUS system, it provides a standardized solution that simplifies maintenance and system upgrades while supporting positively driven or mirror contact configurations depending on the application requirements.
Suitable for
Industrial automation control panels
Expansion of auxiliary contacts in control circuits
Integration with 3RT1 contactors and 3RH1 contactor relays
Systems requiring reliable normally closed signal feedback
When it may not be suitable
This component is specifically designed for use with the Siemens SIRIUS 3RT1 and 3RH1 series. It may not be compatible with contactors from other manufacturers or older product lines that do not support this specific mounting interface. It is not intended for high-power switching applications, as it is strictly an auxiliary control device.
Key specifications
Contact configuration: 1 NC (Normally Closed)
Mounting type: Front-side
Connection type: Spring-type terminal
Compatibility: SIRIUS 3RT1 contactors and 3RH1 contactor relays (sizes S0-S12)
How to use
The auxiliary switch block is designed for straightforward front-side mounting. Ensure the power supply to the main contactor is disconnected before installation. Align the switch block with the designated mounting interface on the front of the 3RT1 or 3RH1 device and press firmly until it clicks into place. Once mounted, insert the control circuit wires into the spring-type terminals, ensuring they are fully seated to establish a reliable electrical connection.
What to consider before purchase
Verify the compatibility with your specific contactor model and size
Ensure the control circuit voltage and current ratings align with the switch specifications
Confirm that the front-side mounting space is available within your control cabinet
Usage recommendations
Always verify that the auxiliary switch is securely locked into the contactor housing before energizing the system. Regularly inspect the spring-type terminals during routine maintenance to ensure connections remain tight and free from debris.

## FAQ

### How much does the Siemens 3RH1921-2CA01 Auxiliary Switch Block cost, and is it available for purchase?

The price is 7.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 10 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 13.07.2026 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. All transactions are 100% secure and encrypted.

### 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

https://aio.lv/img/cache/product/12455728/68795357_large.webp