# Siemens 3UG4511-1AP20 Phase Sequence Monitoring Relay, 3A, 1 Changeover Contact, 0.45s Delay, 320-500V AC

**URL:** https://aio.lv/en/product--siemens-3ug4511-1ap20--12463458
**Data updated:** 2026-05-18 09:43 (EEST)
**Category:** Sensors & Detectors
**Manufacturer:** Siemens
**Manufacturer code:** 3UG4511-1AP20
**EAN:** 4011209642195
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 104.99 €
**Prices and availability valid until:** 2026-07-23 23:59
**Price without VAT (21%):** 86.77 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--siemens-3ug4511-1ap20--12463458

## 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 | 4.99 EUR |

## Summary description

The Siemens 3UG4511-1AP20 is a professional phase sequence monitoring relay designed for industrial electrical systems. It features a 3A current rating, one changeover contact, and a 0.45-second response delay. Operating within a 320-500V AC voltage range, this device ensures reliable protection by monitoring phase sequence and failure, making it an essential component for safeguarding motors and sensitive equipment in various automation applications.

## Long description

The Siemens 3UG4511-1AP20 is a professional-grade phase sequence monitoring relay engineered to provide robust protection for industrial electrical systems. By continuously monitoring the phase sequence and detecting potential phase failures, this device helps prevent damage to motors and sensitive electrical equipment caused by incorrect power supply conditions. It is designed for reliable operation within a voltage range of 320-500V AC, ensuring consistent performance in demanding automation environments.
Advantages
This monitoring relay offers high reliability and precision in detecting phase-related faults, which is critical for maintaining the longevity of industrial machinery. Its compact design allows for efficient integration into control cabinets, while the integrated 0.45-second response delay helps prevent nuisance tripping caused by minor, transient voltage fluctuations. The inclusion of a changeover contact provides versatile switching capabilities, allowing it to be easily incorporated into various safety and control circuits.
Suitable for
Monitoring phase sequence in three-phase industrial networks
Protecting three-phase motors from phase failure
Automation systems requiring reliable power supply monitoring
Control panels for industrial machinery and equipment
When it may not be suitable
This device is specifically designed for three-phase AC systems and is not suitable for single-phase applications or DC power circuits. It should not be used in environments where the operating voltage falls outside the specified 320-500V AC range, as this may result in inaccurate monitoring or device failure.
Key specifications
Operating voltage range: 320-500V AC
Contact configuration: 1 changeover contact
Current rating: 3A
Response delay: 0.45 seconds
Function: Phase sequence and phase failure monitoring
How to use
The relay is designed for standard DIN rail mounting within an electrical control cabinet. Wiring should be performed by a qualified technician in accordance with the provided technical documentation, ensuring that the three-phase supply lines are connected to the designated input terminals. Once installed, the device automatically monitors the phase sequence and status. If a phase failure or incorrect sequence is detected, the internal relay will switch, allowing the connected control circuit to trigger an alarm or shut down the equipment to prevent damage.
What to consider before purchase
Verify that your system voltage is within the 320-500V AC range
Ensure the 3A current rating is sufficient for your control circuit requirements
Confirm that the 0.45s response delay meets your specific application needs
Check available space in your control cabinet for DIN rail installation
Usage recommendations: Always ensure that the power supply is disconnected before performing any installation or maintenance work on the relay. Regularly inspect the device for signs of wear or loose connections to maintain optimal safety and performance.

## FAQ

### How much does the Siemens 3UG4511-1AP20 Phase Sequence Monitoring Relay cost, and is it available for purchase?

The price is 104.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 4 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, Installment. All transactions are 100% secure and encrypted.

### Can Siemens 3UG4511-1AP20 Phase Sequence 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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