# Siemens 3UG5816-1AA40 Line Monitoring Relay, 90-690V AC, 2CO, IO-Link

**URL:** https://aio.lv/en/product--siemens-3ug5816-1aa40--12459022
**Data updated:** 2026-05-18 09:30 (EEST)
**Category:** Sensors & Detectors
**Manufacturer:** Siemens
**Manufacturer code:** 3UG5816-1AA40
**EAN:** 4047621100005
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 205.49 €
**Prices and availability valid until:** 2026-07-21 23:59
**Price without VAT (21%):** 169.83 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--siemens-3ug5816-1aa40--12459022

## 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 3UG5816-1AA40 is a digital line monitoring relay designed for precise voltage control in 3-phase systems. It supports a wide voltage range of 90-690V AC and a frequency range of 15-70Hz. Equipped with 2CO contacts and IO-Link communication, this device monitors phase sequence and asymmetry, ensuring reliable protection and integration in industrial automation and electrical distribution systems.

## Long description

The Siemens 3UG5816-1AA40 is a high-precision digital line monitoring relay engineered for the comprehensive supervision of 3-phase electrical systems. This device provides advanced monitoring capabilities for phase sequence, phase failure, phase asymmetry, frequency, as well as overvoltage and undervoltage conditions. Designed for versatility, it operates within a wide voltage range of 90-690V AC and a frequency range of 15-70Hz, making it suitable for global industrial applications. The integration of IO-Link communication allows for seamless data exchange and remote diagnostics, while the 2CO contact configuration ensures reliable switching performance in demanding electrical distribution environments.
Advantages
This monitoring relay offers significant operational benefits through its digital configuration, which allows for precise adjustments of threshold values and delay times. The compact design helps save valuable space within control cabinets, while the inclusion of a display provides real-time diagnostics regarding the actual system values and the nature of any power faults. The device supports both window monitoring and overshoot or undershoot detection, providing flexible protection strategies. Furthermore, the IO-Link interface facilitates advanced integration into modern automation systems, enabling efficient monitoring and parameterization.
Suitable for
Industrial automation systems
Mobile power systems such as air conditioning compressors and refrigerated containers
Construction site equipment and cranes
Photovoltaic systems and wind turbine installations
Electrical distribution networks with unstable power supply
When it may not be suitable
This device is specifically designed for 3-phase AC systems and is not intended for use in DC-only circuits. It may not be suitable for applications requiring safety functions exceeding SIL 1/PL c certification levels, unless additional external safety measures are implemented.
Key specifications
Voltage range: 90-690V AC
Frequency range: 15-70Hz
Output contacts: 2 changeover (2CO)
Communication: IO-Link
Monitoring functions: Phase sequence, phase failure, asymmetry, frequency, overvoltage, undervoltage
Connection type: Screw terminals
How to use
Installation should be performed by qualified personnel in accordance with local electrical regulations. The relay is mounted on a standard DIN rail within a control cabinet. After physical installation, connect the 3-phase supply lines to the designated terminals. Use the digital interface to set the required monitoring parameters, such as voltage thresholds and time delays. If using the IO-Link functionality, connect the device to the IO-Link master to enable remote parameterization and data transmission. Ensure that all terminal connections are tightened securely to maintain reliable contact.
What to consider before purchase
Verify that your system voltage and frequency fall within the specified 90-690V AC and 15-70Hz range.
Confirm that your control system supports IO-Link communication if you intend to utilize remote diagnostic features.
Ensure there is sufficient space in the control cabinet for the device dimensions.
Check if your application requires specific safety certifications like SIL 1/PL c.
Usage recommendations
Regularly check the diagnostic display to monitor the health of the electrical network and ensure that all terminal connections remain secure, especially in environments subject to vibration.

## FAQ

### How much does the Siemens 3UG5816-1AA40 Line Monitoring Relay cost, and is it available for purchase?

The price is 205.49 € (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 3UG5816-1AA40 Line 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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