# Siemens 3UG5512-1BR21 SIRIUS Phase Monitoring Relay, 3-Phase 160-690V AC, 2CO Contacts

**URL:** https://aio.lv/en/product--siemens-3ug5512-1br21--12469042
**Data updated:** 2026-05-18 09:43 (EEST)
**Category:** Sensors & Detectors
**Manufacturer:** Siemens
**Manufacturer code:** 3UG5512-1BR21
**EAN:** 4047621099903
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 123.49 €
**Prices and availability valid until:** 2026-08-01 23:59
**Price without VAT (21%):** 102.06 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--siemens-3ug5512-1br21--12469042

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 22.07.2026 | free |
| Pickup points | 27.07.2026 | 1.89 EUR |
| Courier delivery to door | 27.07.2026 | 4.99 EUR |

## Summary description

The Siemens 3UG5512-1BR21 SIRIUS monitoring relay is designed for reliable protection of 3-phase networks. It monitors phase sequence, phase failure, and asymmetry within a voltage range of 160-690V AC and a frequency of 15-70Hz. Equipped with 2 changeover (2CO) contacts and screw terminals, this device ensures industrial safety and operational stability in electrical systems.

## Long description

The Siemens 3UG5512-1BR21 SIRIUS phase monitoring relay is a high-performance industrial device engineered to ensure the operational integrity of 3-phase electrical networks. By continuously monitoring for phase sequence, phase failure, and phase asymmetry, this relay provides essential protection for sensitive equipment and machinery. It is designed to operate within a broad voltage range of 160-690V AC and a frequency range of 15-70Hz, making it a versatile solution for diverse global electrical environments.
Advantages
This monitoring relay offers significant benefits for industrial automation and power management. Its compact, slim design helps optimize space within control cabinets, allowing for more efficient panel layouts. The device features removable terminals, which simplifies installation and maintenance procedures. With its wide voltage range and the ability to function without auxiliary voltage, it is suitable for deployment in various international power grids. Furthermore, the relay is certified for SIL 1/PL c, ensuring a high level of functional safety for critical applications.
Suitable for
Air conditioning compressors
Refrigerated containers
Construction site compressors
Industrial cranes
Photovoltaic systems
Wind turbines
This device may not be suitable for single-phase electrical systems or DC power applications, as it is specifically designed for 3-phase network monitoring. It should not be used in environments where the electrical parameters exceed the specified voltage or frequency ranges, as this could lead to inaccurate monitoring or device failure.
Key specifications
Monitoring functions: Phase sequence, phase failure, and phase asymmetry
Voltage range: 3-phase 160-690V AC
Frequency range: 15-70Hz
Output contacts: 2 changeover (2CO) contacts
Connection type: Screw terminals
Safety certification: SIL 1/PL c
Installation should be performed by qualified personnel in accordance with local electrical regulations. The relay is mounted in the control cabinet, and the 3-phase supply lines are connected to the designated input terminals. Once powered, the device automatically begins monitoring the network parameters. The 2CO contacts can be integrated into the control circuit to trigger alarms or disconnect power in the event of a detected fault, such as a phase loss or incorrect sequence.
What to consider before purchase
Verify that your network voltage falls within the 160-690V AC range.
Ensure the 3-phase configuration matches the relay requirements.
Confirm that the screw terminal connection is compatible with your existing wiring standards.
Check if the SIL 1/PL c safety level meets your specific project requirements.
For optimal performance and safety, ensure that the relay is installed in a clean, dry environment protected from excessive vibration. Regularly inspect the terminal connections to maintain a secure electrical contact and ensure the device remains within its specified operating temperature range.

## FAQ

### How much does the Siemens 3UG5512-1BR21 SIRIUS Phase Monitoring Relay cost, and is it available for purchase?

The price is 123.49 € (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 22.07.2026 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 3UG5512-1BR21 SIRIUS 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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