Product Description

Siemens 3RF2190-1AA45 Solid-State Relay – 90 A, 48–600 V AC, 4–30 V DC

The Siemens 3RF2190-1AA45 is a SIRIUS 3RF21 single-phase solid-state relay designed for applications requiring frequent contactless switching. It uses semiconductor switching technology instead of mechanical contacts, making it suitable for repetitive switching operations in industrial automation and control systems.

The relay has a 22.5 mm installation width, supports a 48–600 V AC load voltage, uses a 4–30 V DC control input, and has a specified maximum current class of 90 A. Siemens identifies the device as a 1-pole solid-state relay with zero-point switching and screw terminals, intended for mounting on a suitable cooling surface.

Siemens SIRIUS 3RF Solid-State Relay

The 3RF2190-1AA45 belongs to the Siemens SIRIUS 3RF21 solid-state relay family, developed for industrial applications where switching occurs frequently and mechanical contact wear would be undesirable.

Unlike conventional electromechanical contactors and relays, a solid-state relay uses semiconductor devices to switch the load. This allows high switching frequency and eliminates mechanical contact bouncing.

Typical applications include:

• Industrial automation

• Heating control

• Resistance heaters

• Machine-control systems

• Process control

• Packaging machinery

• Temperature-control systems

• Conveyor equipment

• Production machinery

• OEM control panels

Contactless Switching for Frequent Operations

The primary advantage of the 3RF2190-1AA45 is its contactless semiconductor switching.

Because there are no conventional mechanical power contacts, the relay is suitable for applications where the load must be switched repeatedly.

Typical high-frequency switching applications include:

• Electric heaters

• Heating elements

• Temperature-control systems

• Industrial ovens

• Furnaces

• Packaging equipment

• Plastic-processing machinery

• Process-heating systems

• Automated production equipment

The appropriate heat sink and operating conditions must be selected according to the actual load current and installation requirements.

90 A Current Class

The 3RF2190-1AA45 is specified in the 90 A current class. Siemens' product data identifies the maximum current capability as 90 A, while the actual permissible operating current depends on cooling conditions, ambient temperature, connection method and application.

The relay therefore requires proper thermal management when operating at higher currents.

For the 3RF2190-1AA45, Siemens specifically notes that it is to be used with a suitable heat sink.

48–600 V AC Load Voltage

The 3RF2190-1AA45 is designed for AC loads in the 48–600 V AC range. Siemens product data identifies the operating-voltage range and a 1200 V blocking voltage.

This makes the relay suitable for a broad range of industrial AC loads, subject to correct current, thermal and application ratings.

4–30 V DC Control Input

The relay uses a 4–30 V DC control input.

This makes it suitable for control signals from:

• PLC digital outputs

• Electronic controllers

• Automation systems

• Temperature controllers

• Sensors and control modules

• Industrial switching circuits

The control output should be checked to confirm compatibility with the relay's specified input range.

Zero-Point Switching

The 3RF2190-1AA45 uses zero-point switching.

With zero-crossing switching, the semiconductor relay switches the AC load near the zero crossing of the AC waveform. This can help reduce switching disturbances and is particularly useful for suitable resistive heating loads.

Siemens product data identifies the zero-point switching function for this article.

Screw-Terminal Connections

The 3RF2190-1AA45 uses screw terminals, providing a familiar connection method for industrial electrical panels.

This supports practical installation and maintenance for control and load wiring when the relay is installed according to Siemens' requirements. Siemens lists the article with screw-terminal connections.

22.5 mm Compact Design

The relay has a compact 22.5 mm mounting width.

This compact form factor makes it suitable for control panels where efficient use of cabinet space is important.

It can be integrated into:

• Automation cabinets

• Heating-control panels

• Machine-control panels

• OEM control systems

• Industrial process-control panels

Suitable Heat Sink Required

Because solid-state switching devices generate heat during operation, thermal management is an important part of installation.

Siemens and current Siemens pricing documentation specify that the 3RF2190-1AA45 should be used with a suitable heat sink.

The required cooling solution depends on the actual current, ambient temperature and mounting conditions. The relay should not be operated at its maximum current without ensuring adequate thermal dissipation.

Industrial Automation Applications

The 3RF2190-1AA45 can be used in applications requiring frequent AC load switching.

Industrial Heating

It can control compatible heating elements in industrial ovens, furnaces and process-heating systems.

Temperature Control

The relay can be switched repeatedly by a temperature controller or PLC to regulate suitable resistive loads.

Packaging Machinery

High-frequency switching can be useful for heating and sealing functions in automated packaging equipment.

Plastic Processing

It can be incorporated into suitable heating-control systems for plastic-processing machinery.

Process Automation

The relay can be integrated into automated systems where frequent semiconductor-based AC switching is required.

Suitable for OEMs and Panel Builders

The 3RF2190-1AA45 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its combination of contactless switching, 90 A current class, 48–600 V AC load voltage, 4–30 V DC input, zero-point switching and compact 22.5 mm design makes it suitable for high-frequency industrial switching applications.

Key Features

• Siemens SIRIUS 3RF21 solid-state relay

• Article number 3RF2190-1AA45

• Single-phase design

• 1-pole semiconductor switching

• 90 A maximum current class

• 48–600 V AC operating voltage

• 4–30 V DC control input

• Zero-point switching

• 1200 V blocking voltage

• 22.5 mm mounting width

• Screw terminals

• Suitable heat sink required

• Contactless switching

• Suitable for frequent switching applications

• Suitable for industrial automation

Benefits

• Contactless switching: Eliminates mechanical power-contact wear.

• Frequent switching capability: Suitable for applications requiring repeated switching cycles.

• Wide AC load range: Supports compatible AC loads from 48 to 600 V.

• 4–30 V DC control: Suitable for PLCs and electronic automation controls.

• Zero-point switching: Helps provide controlled switching of suitable AC loads.

• Compact design: 22.5 mm width helps save panel space.

• Longer switching life: Semiconductor switching avoids mechanical contact erosion.

• Industrial integration: Suitable for automation, heating and process-control systems.

Why Choose Siemens 3RF2190-1AA45?

The Siemens 3RF2190-1AA45 is designed for industrial applications where conventional mechanical switching is not ideal because the load must be switched frequently.

Its semiconductor-based contactless switching, 90 A current class, 48–600 V AC load range, 4–30 V DC control input and zero-point switching make it a strong option for compatible industrial heating and automation applications.

The compact 22.5 mm housing also helps optimize control-panel space. Proper heat sinking is essential, especially at higher operating currents.

Delivery Across India

SB Smart supplies Siemens industrial electrical and automation products across Faridabad, Gurgaon/Gurugram, Delhi NCR, Haryana, Noida, Punjab, Mumbai and major cities across India.

Major delivery locations include:

• Faridabad

• Gurgaon/Gurugram

• Delhi

• Delhi NCR

• Noida

• Greater Noida

• Haryana

• Punjab

• Mumbai

• Pune

• Ahmedabad

• Bengaluru

• Hyderabad

• Chennai

• Kolkata

• Jaipur

• Chandigarh

• Lucknow

• Indore

• Surat

• Vadodara

• Nagpur

• Coimbatore

• And other major cities across India

Frequently Asked Questions

1. What is Siemens 3RF2190-1AA45?

It is a Siemens SIRIUS 3RF21 single-phase solid-state relay designed for frequent contactless AC load switching.

2. What is its maximum current class?

The product is specified in the 90 A maximum current class. The actual permitted operating current depends on cooling and installation conditions.

3. What AC load voltage does it support?

It supports 48–600 V AC operating voltage.

4. What is the control input?

The control input is 4–30 V DC.

5. Does it use zero-point switching?

Yes. The 3RF2190-1AA45 uses zero-point switching.

6. Does it require a heat sink?

Yes. Siemens specifies that this 90 A version must be used with a suitable heat sink.

7. What is the mounting width?

The relay has a 22.5 mm width.

8. Does it use screw terminals?

Yes. The product uses screw-terminal connections.

9. Where can it be used?

It is suitable for frequent AC switching applications, especially compatible industrial heating, temperature-control, process-control and automation systems.

10. Where can I buy Siemens 3RF2190-1AA45 in India?

You can explore the Siemens industrial electrical and automation product range at SB Smart for solid-state relays, contactors, control components and related products.