Siemens 3RT6025-1BB40 Power Control Contactor Relay Set 24VDC 17A 3NO

The Siemens 3RT6025-1BB40 is a robust 24VDC power control contactor relay set designed for reliable switching of loads up to 17A with three normally open (3NO) auxiliary contacts. Engineered for demanding industrial environments, this compact and efficient component offers superior operational longevity and precise control, making it a cornerstone for automation systems requiring dependable power management. Its key advantages include high switching capacity, low power consumption, and seamless integration into Siemens' comprehensive industrial control ecosystems, ensuring operational continuity and enhanced system performance.

Product Specifications

| Specification             | Value                                    |

| :------------------------ | :--------------------------------------- |

| Manufacturer              | Siemens                                  |

| Product Number            | 3RT6025-1BB40                            |

| Type                      | Power Control Contactor Relay Set        |

| Coil Voltage              | 24V DC                                   |

| Rated Operational Current | 17A                                      |

| Number of NO Contacts     | 3                                        |

| Number of NC Contacts     | 0                                        |

| Auxiliary Contact Type    | Normally Open (NO)                       |

| Mounting Type             | Rail Mount (35mm DIN rail)               |

| Terminal Type             | Screw Terminals                          |

| Ambient Operating Temp.   | -25°C to +60°C                           |

| Protection Class          | IP20                                     |

| Dimensions (H x W x D)    | Approx. 83mm x 45mm x 97mm               |

Core Features & Market Positioning

The Siemens 3RT6025-1BB40 distinguishes itself through its exceptional reliability and advanced construction, designed to meet stringent industrial standards. Its solid-state switching technology (though this specific model is electromechanical, the broader Siemens range often includes solid-state options, and the design ethos emphasizes robustness) ensures consistent performance and a high number of switching cycles, minimizing downtime and maintenance requirements. This contactor relay set is positioned as a premium solution for applications where precision, durability, and energy efficiency are paramount, directly competing with other leading industrial control manufacturers by offering a blend of performance and integration within the Siemens Totally Integrated Automation (TIA) portfolio. Its 24VDC coil voltage is ideal for safety-critical systems and battery-powered applications.

Key Application Scenarios

This Siemens contactor relay set finds extensive use in various industrial automation tasks. It is commonly employed for controlling motors, heating elements, lighting circuits, and solenoid valves in manufacturing plants, process control systems, and building automation. Specifically, the 3RT6025-1BB40 is well-suited for applications requiring frequent switching operations, such as in packaging machinery, conveyor systems, and HVAC control units. Its 17A rating makes it capable of handling moderate power loads, while the 3NO auxiliary contacts provide crucial feedback for control circuits, enabling complex interlocking and status monitoring within automated processes. Users frequently search for solutions to control AC motors with DC control circuits, a primary application for this device.

Practical System Integration Guidance

Integrating the Siemens 3RT6025-1BB40 into an existing control system is straightforward due to its standard DIN rail mounting and screw terminal connections. For wiring, ensure the 24VDC power supply is correctly connected to the coil terminals (typically A1 and A2), observing polarity if applicable. The main power circuit is connected to the high-current terminals, while the 3NO auxiliary contacts can be wired into PLC inputs or other control logic circuits to signal the contactor's operational status. It's crucial to adhere to local electrical codes and ensure proper wire gauge selection for the 17A load. Compatibility with other Siemens components, such as PLCs from the S7 series and HMI panels, is seamless, allowing for efficient system design and programming within the TIA Portal environment.

Operation and Risk Mitigation

Operating the Siemens 3RT6025-1BB40 involves ensuring it receives the correct 24VDC coil voltage to activate the switching mechanism and control the 17A load. The device is designed with built-in protection against transient overvoltages, but it's essential to implement appropriate surge suppression if the application environment is prone to electrical disturbances. Risks associated with this product are primarily related to improper installation or exceeding its rated parameters. Always ensure the ambient temperature remains within the specified range (-25°C to +60°C) and that the enclosure provides adequate IP20 protection against solid objects. Failure to do so can lead to premature wear or operational failure. Regular visual inspections for signs of overheating or damage are recommended.

Scalability & Long-Term Value

The Siemens 3RT6025-1BB40 offers excellent scalability within the broader Siemens industrial control portfolio. Its compatibility with other Siemens contactors, relays, and control modules allows for phased system upgrades and expansion. For users looking to leverage Industry 4.0 capabilities, integrating this contactor into a Siemens S7 PLC system enables data acquisition on its operational status and load conditions. This data can be fed into SCADA systems or IIoT platforms for predictive maintenance, performance monitoring, and remote diagnostics, significantly enhancing the long-term value and operational efficiency of the automated system. Its robust construction also ensures a long service life, reducing the total cost of ownership.

Frequently Asked Questions (FAQs)

1. What is the primary function of the Siemens 3RT6025-1BB40?

This contactor relay acts as an electrically operated switch. It uses a low-voltage DC coil to control a higher power circuit.

It is ideal for switching motors, lights, and other loads up to 17 amps. The 3NO contacts provide status feedback.

2. Can the Siemens 3RT6025-1BB40 be used to control AC motors?

Yes, it can control AC motors, provided the motor's operating current and voltage are within the contactor's 17A rating. The DC coil allows for separate control power.

3. What type of electrical connection does the Siemens 3RT6025-1BB40 use?

It features standard screw terminals for both the power circuit and auxiliary contacts. This ensures secure and reliable connections.

4. How does the 24VDC coil voltage benefit my application?

A 24VDC coil is safer and ideal for low-voltage control systems and battery power. It simplifies wiring and reduces shock hazards.

5. What does "3NO" mean in the product description?

"3NO" signifies three Normally Open auxiliary contacts. These contacts close when the main contactor coil is energized.

6. Is the Siemens 3RT6025-1BB40 suitable for harsh industrial environments?

With an IP20 rating and a wide operating temperature range, it is built for many industrial settings. Ensure proper enclosure for added protection.

7. How do I install the Siemens 3RT6025-1BB40?

It mounts easily onto a standard 35mm DIN rail. Secure wiring with appropriate tools and ensure all connections are tight.

8. Can I use this contactor with non-Siemens PLCs?

Yes, its standard electrical interfaces allow integration with most PLCs. Verify coil voltage and current ratings match your control system.

9. What maintenance is required for this Siemens contactor relay?

Generally, minimal maintenance is needed due to its robust design. Regular visual checks for wear or damage are recommended.

10. What is the maximum switching frequency for the 3RT6025-1BB40?

While specific frequency limits vary, this electromechanical contactor is designed for frequent operation. Consult the datasheet for precise figures.