# Siemens SIRIUS 3UG5512-2BR20 Phase Monitoring Relay, 3-Phase, 160-690V AC, 2CO Contacts

**URL:** https://aio.lv/en/product--siemens-3ug5512-2br20--12464901
**Data updated:** 2026-05-18 09:27 (EEST)
**Category:** Sensors & Detectors
**Manufacturer:** Siemens
**Manufacturer code:** 3UG5512-2BR20
**EAN:** 4047621099873
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 112.49 €
**Prices and availability valid until:** 2026-08-07 23:59
**Price without VAT (21%):** 92.97 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--siemens-3ug5512-2br20--12464901

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 28.07.2026 | free |
| Pickup points | 31.07.2026 | 1.89 EUR |
| Courier delivery to door | 31.07.2026 | 4.99 EUR |

## Summary description

The Siemens SIRIUS 3UG5512-2BR20 is a professional phase monitoring relay designed to detect phase failure, incorrect phase sequence, and asymmetry in 3-phase networks. Operating within a voltage range of 160-690V AC and 15-70Hz, it features 2 changeover (2CO) contacts and reliable spring-type terminals. This device ensures industrial equipment protection by monitoring supply quality and preventing operational faults caused by power irregularities.

## Long description

The Siemens SIRIUS 3UG5512-2BR20 is a high-performance phase monitoring relay engineered to provide comprehensive protection for 3-phase electrical networks. It is specifically designed to detect critical power issues such as phase failure, incorrect phase sequence, and phase asymmetry, ensuring that industrial equipment remains safe from damage caused by unstable power supply conditions. This relay is built for reliability and versatility, making it an essential component for maintaining operational continuity in demanding industrial environments.
Advantages
This monitoring relay offers significant benefits, including a wide operating voltage range that allows for global application without the need for auxiliary power. Its slim design helps optimize space within control cabinets, while the integrated spring-loaded terminals ensure a fast, vibration-proof, and maintenance-free connection. The device is built to replace the proven 3UG4 series, offering improved performance and standardized accessories for easier installation and maintenance.
Suitable for
Monitoring phase sequence and failure in mobile systems like A/C compressors
Refrigerated containers and transport cooling units
Construction site compressors and heavy-duty cranes
Photovoltaic systems and wind turbine power management
When it may not be suitable
This device is intended for 3-phase AC networks and is not suitable for single-phase applications or DC power monitoring. It should not be used in environments that exceed the specified voltage or frequency ranges, as this may lead to inaccurate monitoring or device failure.
Key specifications
Voltage range: 160-690V AC
Frequency range: 15-70 Hz
Contacts: 2 changeover (2CO) contacts
Connection type: Spring-loaded terminals
Functionality: Phase failure, phase sequence, and asymmetry monitoring
How to use
The relay should be installed by a qualified professional within a control cabinet. Connect the 3-phase supply lines to the designated terminals. The spring-loaded connection system allows for quick wire insertion without the need for constant retightening. Once installed, the device automatically monitors the network parameters. Ensure that the wiring is secure and that the device is protected from environmental factors like excessive moisture or dust, as per standard industrial installation practices.
What to consider before purchase
Verify that your network voltage falls within the 160-690V AC range
Ensure the application requires 3-phase monitoring
Confirm that the spring-loaded terminal type is compatible with your existing wiring standards
Check if your specific safety requirements necessitate SIL 1/PL c certified versions
Usage recommendations
For optimal performance and longevity, ensure the relay is mounted in a clean, dry environment within a control cabinet. Regularly inspect the spring-loaded connections during routine maintenance to ensure they remain secure, especially in high-vibration applications.

## FAQ

### How much does the Siemens SIRIUS 3UG5512-2BR20 Phase Monitoring Relay cost, and is it available for purchase?

The price is 112.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 2 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 28.07.2026 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 SIRIUS 3UG5512-2BR20 Phase Monitoring 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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