# Siemens SIRIUS 3RH1921-1CA01 Auxiliary Switch Block, 1 NC Contact, Front-Mounting

**URL:** https://aio.lv/en/product--siemens-3rh1921-1ca01--1839364
**Data updated:** 2026-05-18 02:42 (EEST)
**Category:** Printer & Copier Parts
**Manufacturer:** Siemens
**Manufacturer code:** 3RH1921-1CA01
**EAN:** 4011209281639
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 15.99 €
**Prices and availability valid until:** 2026-07-21 23:59
**Price without VAT (21%):** 13.21 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--siemens-3rh1921-1ca01--1839364

## 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 | 7.10 EUR |

## Summary description

The Siemens SIRIUS 3RH1921-1CA01 is a single-pole auxiliary switch block designed for front mounting. It features one normally closed (NC) contact and is compatible with SIRIUS contactors. This modular component is essential for expanding control circuit capabilities in industrial automation and electrical switching systems, ensuring reliable signal transmission and operational safety.

## Long description

The Siemens SIRIUS 3RH1921-1CA01 is a high-quality auxiliary switch block engineered for seamless integration with SIRIUS contactors. This single-pole component is designed for front-mounting, providing a reliable normally closed (NC) contact to expand the switching capabilities of your electrical control systems. It is built to meet the rigorous demands of industrial automation, ensuring precise signal transmission and consistent performance in various switching applications.
Advantages
This auxiliary switch block offers exceptional reliability and ease of installation due to its modular design. By allowing for quick front-mounting onto compatible contactors, it simplifies the process of upgrading or modifying control circuits without requiring extensive downtime. The robust construction ensures long-term operational safety and durability, making it an essential addition for maintaining efficient electrical switching systems in demanding industrial environments.
Suitable for
Industrial automation control panels
Motor control and protection systems
Electrical signal feedback loops
Expanding contactor switching capacity
When it may not be suitable
This component is specifically designed for use with compatible Siemens SIRIUS contactors and may not be physically or electrically compatible with contactors from other manufacturers or different product series. It is not intended for high-power switching applications, as it is strictly an auxiliary device for control circuits.
Key specifications
Contact configuration: 1 normally closed (NC)
Mounting type: Front-mounting
Compatibility: Siemens SIRIUS contactors
Pole count: Single-pole
How to use
To install the auxiliary switch block, ensure that the power supply to the contactor is completely disconnected. Align the switch block with the front-mounting interface of the compatible SIRIUS contactor and press firmly until it clicks into place. Once secured, verify the mechanical connection and proceed to wire the NC contact into your control circuit according to your system schematic. Always perform a functional test before returning the system to full operation.
What to consider before purchase
Verify compatibility with your existing contactor model
Ensure the NC contact configuration meets your control logic requirements
Confirm that the front-mounting space is available within your enclosure
Usage recommendations
Always ensure that the electrical load connected to the auxiliary contact does not exceed the rated specifications to prevent damage to the switch block and ensure the longevity of your control system.

## FAQ

### How much does the Siemens SIRIUS 3RH1921-1CA01 Auxiliary Switch Block cost, and is it available for purchase?

The price is 15.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 23 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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