# Siemens SIRIUS 3RH1921-1CA10 Auxiliary Switch Block, 1 NO Contact, Front Mounting

**URL:** https://aio.lv/en/product--siemens-3rh1921-1ca10--1839365
**Data updated:** 2026-05-18 02:42 (EEST)
**Category:** Server Parts & Components
**Manufacturer:** Siemens
**Manufacturer code:** 3RH1921-1CA10
**EAN:** 4011209281332
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 18.49 €
**Prices and availability valid until:** 2026-07-23 23:59
**Price without VAT (21%):** 15.28 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--siemens-3rh1921-1ca10--1839365

## 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 | 8.15 EUR |

## Summary description

The Siemens SIRIUS 3RH1921-1CA10 is a high-quality auxiliary switch block designed for reliable switching operations. Featuring 1 normally open (NO) contact, this 1-pole unit is intended for front mounting on SIRIUS contactors. It is an essential component for industrial automation and control systems, ensuring precise signal transmission and operational safety in various electrical configurations.

## Long description

The Siemens SIRIUS 3RH1921-1CA10 is a professional-grade auxiliary switch block engineered for integration with SIRIUS contactors. This 1-pole unit features a single normally open (NO) contact, providing a reliable solution for expanding the switching capabilities of industrial control systems. Designed for front mounting, it allows for efficient installation and space-saving configuration within electrical panels.
Advantages
This auxiliary switch block offers exceptional mechanical durability and electrical reliability, ensuring consistent performance in demanding industrial environments. Its front-mounting design simplifies the assembly process, allowing for quick integration into existing contactor setups without requiring additional side space. The high-quality construction ensures precise signal transmission, which is critical for the stable operation of complex automation and control circuits.
Suitable for
Industrial automation systems
Control and monitoring circuits
Signal transmission in electrical panels
Expansion of contactor switching functions
When it may not be suitable
This component is specifically designed for use with compatible Siemens SIRIUS contactors and may not be compatible with other brands or older series of contactors. It is not intended for high-power switching applications, as it is strictly an auxiliary device for control signals.
Key specifications
Contact configuration: 1 normally open (NO)
Mounting type: Front mounting
Compatibility: SIRIUS contactor series
Number of poles: 1-pole
How to use
To install the auxiliary switch block, ensure that the power supply to the contactor is disconnected. Align the unit with the front mounting interface of the compatible SIRIUS contactor and press it firmly until it clicks into place. Once secured, connect the control wiring to the terminals according to your specific circuit diagram. Verify that the contact operates correctly by testing the signal transmission before putting the system back into full operation.
What to consider before purchase
Verify compatibility with your specific SIRIUS contactor model
Ensure the control circuit requirements match the 1 NO contact configuration
Confirm that front mounting space is available in your electrical cabinet
Usage recommendations
Always perform a functional test of the auxiliary switch after installation to ensure the normally open contact closes correctly when the contactor is energized. Regularly inspect terminal connections for tightness to maintain optimal electrical conductivity.

## FAQ

### How much does the Siemens SIRIUS 3RH1921-1CA10 Auxiliary Switch Block cost, and is it available for purchase?

The price is 18.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 113 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. 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

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