# Siemens SIRIUS 3RW4028-1BB04 Soft Starter, 3-Phase, 200-480V AC, 38A, 18.5kW at 400V, 24V AC/DC Control Supply

**URL:** https://aio.lv/en/product--siemens-3rw4028-1bb04--3271823
**Data updated:** 2026-05-18 02:54 (EEST)
**Category:** Control Systems
**Manufacturer:** Siemens
**Manufacturer code:** 3RW4028-1BB04
**EAN:** 4011209691766
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 673.99 €
**Prices and availability valid until:** 2026-07-29 23:59
**Price without VAT (21%):** 557.02 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--siemens-3rw4028-1bb04--3271823

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 16.07.2026 | free |
| Pickup points | 21.07.2026 | 1.89 EUR |
| Courier delivery to door | 21.07.2026 | 4.99 EUR |

## Summary description

The Siemens SIRIUS 3RW4028-1BB04 is a compact 3-phase soft starter designed for smooth motor starting and stopping. It operates at 200-480V AC with a rated current of 38A and a power capacity of 18.5kW at 400V. Featuring a 24V AC/DC control supply and S0 frame size, this device reduces mechanical stress and current peaks in industrial motor applications, ensuring reliable performance and extended equipment lifespan.

## Long description

The Siemens SIRIUS 3RW4028-1BB04 is a high-performance 3-phase soft starter engineered to provide controlled acceleration and deceleration for industrial electric motors. By managing the voltage supplied to the motor during startup, this device effectively eliminates mechanical shocks and reduces high inrush current peaks that can strain power grids and mechanical components. Its compact S0 frame size makes it an ideal solution for space-constrained control cabinets, while its robust design ensures consistent operation in demanding industrial environments.
Advantages
This soft starter offers significant benefits by extending the operational lifespan of motors and connected mechanical systems such as belts, gears, and couplings. By facilitating a smooth transition from standstill to full speed, it minimizes wear and tear on drive components. The integrated electronic overload protection provides an additional layer of safety, preventing motor damage due to overheating or excessive current draw. Furthermore, the device is designed for energy efficiency and reliable performance, contributing to reduced maintenance requirements and improved overall system stability.
Suitable for
Conveyor belt systems
Industrial pumps and fans
Compressor units
Centrifugal machines
Small to medium-sized industrial motor drives
When it may not be suitable
This device is not intended for applications requiring frequent reversing of motor direction or high-frequency starting cycles that exceed the thermal capacity of the unit. It is also not suitable for single-phase motor applications or systems requiring precise speed control beyond the initial startup phase.
Key specifications
Rated operational voltage: 200-480V AC
Rated operational current: 38A
Power capacity: 18.5kW at 400V
Control supply voltage: 24V AC/DC
Frame size: S0
Phase count: 3-phase
How to use
Installation should be performed by qualified personnel in accordance with local electrical regulations. The unit is designed for mounting on standard DIN rails or screw mounting within an enclosure. Ensure that the control supply voltage is correctly connected to the designated terminals and that the main power lines are properly phased. Once installed, the soft starter parameters can be adjusted to match the specific requirements of the motor load, ensuring optimal ramp-up and ramp-down times.
What to consider before purchase
Verify that the motor power rating is compatible with the 18.5kW capacity at 400V.
Ensure the control circuit provides a stable 24V AC/DC supply.
Check the available space in the control cabinet for the S0 frame size.
Confirm that the ambient temperature and ventilation conditions meet the manufacturer's requirements.
Usage recommendations
Regularly inspect the terminal connections for tightness and ensure the cooling vents remain free of dust or debris to maintain optimal thermal performance.

## FAQ

### How much does the Siemens SIRIUS 3RW4028-1BB04 Soft Starter cost, and is it available for purchase?

The price is 673.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 3 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 16.07.2026 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, Leasing for legal entities. All transactions are 100% secure and encrypted.

### Can Siemens SIRIUS 3RW4028-1BB04 Soft Starter 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

https://aio.lv/img/cache/product/3271823/47519067_large.webp