# Siemens 3RN2012-1BW30 Thermistor Motor Protection Relay, 24-240V AC/DC, Screw Terminals

**URL:** https://aio.lv/en/product--siemens-3rn20121bw30--1805595
**Data updated:** 2026-05-18 02:47 (EEST)
**Category:** Control Systems
**Manufacturer:** Siemens
**Manufacturer code:** 3RN20121BW30
**EAN:** 4047621006635
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 132.99 €
**Prices and availability valid until:** 2026-07-19 23:59
**Price without VAT (21%):** 109.91 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--siemens-3rn20121bw30--1805595

## 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 3RN2012-1BW30 is a high-quality thermistor motor protection relay designed for reliable monitoring of motor temperatures. It features a wide supply voltage range of 24-240V AC/DC and is equipped with two changeover contacts. Utilizing screw terminals for secure installation, this device is ideal for industrial automation systems requiring precise thermal protection and operational safety.

## Long description

The Siemens 3RN2012-1BW30 thermistor motor protection relay is a robust industrial component engineered to monitor motor temperatures by evaluating resistance changes in integrated thermistors. This device ensures operational safety by detecting overheating conditions and triggering a protective response, thereby preventing potential motor damage in demanding industrial environments. Its versatile design supports a wide supply voltage range, making it compatible with various control system architectures.
Advantages
This relay offers exceptional reliability through its precise temperature monitoring capabilities, which are essential for maintaining the longevity of electric motors. The inclusion of two changeover contacts provides flexibility in control circuit design, allowing for multiple signaling or shutdown configurations. Furthermore, the use of secure screw terminals ensures a stable and vibration-resistant connection, which is critical for long-term performance in industrial settings. The wide-range power supply simplifies inventory management and installation by reducing the need for multiple device variants.
Suitable for
Industrial motor protection systems
Monitoring temperature in heavy-duty machinery
Automation control panels requiring thermal feedback
Applications where motor overheating poses a risk to equipment
When it may not be suitable
This device is specifically designed for use with PTC thermistor sensors and will not function correctly with other types of temperature sensors like thermocouples or RTDs. It is not intended for direct motor control of high-current loads without an intermediate contactor or relay.
Key specifications
Supply voltage: 24-240V AC/DC
Contact configuration: 2 changeover contacts
Connection type: Screw terminals
Function: Thermistor motor protection
How to use
To install the relay, mount it onto a standard DIN rail within the control cabinet. Connect the PTC thermistor sensor leads to the designated input terminals on the device. Wire the output contacts into your motor control circuit to ensure that the motor is de-energized when the relay detects an over-temperature state. Ensure all screw terminals are tightened to the manufacturer's specified torque to maintain a secure electrical connection.
What to consider before purchase
Verify that your motor is equipped with compatible PTC thermistors.
Ensure the control voltage matches the 24-240V AC/DC range.
Check available space in your control cabinet for DIN rail mounting.
Usage recommendations
Regularly test the relay functionality during scheduled maintenance to ensure the thermal protection circuit remains active and responsive to simulated fault conditions.

## FAQ

### How much does the Siemens 3RN2012-1BW30 Thermistor Motor Protection Relay cost, and is it available for purchase?

The price is 132.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 5 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, Installment. All transactions are 100% secure and encrypted.

### Can Siemens 3RN2012-1BW30 Thermistor Motor Protection Relay 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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