Siemens 3RT2526-1BM40 High Performance Industrial Control Contactor 220VDC 25A 2NO+2NC

The Siemens 3RT2526-1BM40 is a high-performance industrial control contactor engineered for demanding applications, boasting a 220VDC coil and a robust 25A switching capacity. This device exemplifies Siemens' commitment to reliability and efficiency, featuring a compact design with 2 Normally Open (NO) and 2 Normally Closed (NC) auxiliary contacts, facilitating complex control circuits and diagnostics. Its high performance is underscored by its ability to handle significant inductive loads and ensure operational continuity in critical industrial environments.

Siemens 3RT2526-1BM40: Product Specifications

| Parameter              | Specification                                    |

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

| Product Type           | Power Contactor                                  |

| Manufacturer           | Siemens                                          |

| Series                 | SIRIUS 3RT2                                      |

| Model Number           | 3RT2526-1BM40                                    |

| Coil Voltage           | 220 V DC                                         |

| Rated Operational Current (AC-1, 400V) | 25 A                                             |

| Rated Operational Current (AC-3, 400V) | 25 A                                             |

| Number of Auxiliary Contacts | 2 NO + 2 NC                                      |

| Enclosure Type         | IP20                                             |

| Mounting Type          | Screw Terminals, Spring-loaded Terminals         |

| Dimensions (H x W x D) | 86 mm x 55 mm x 96 mm                            |

| Ambient Temperature    | -25 to +60 °C                                    |

| Standards              | IEC/EN 60947-4-1, VDE 0660                       |

Core Features & Market Positioning

The Siemens 3RT2526-1BM40 stands out in the industrial control market due to its superior reliability and compact footprint. Its integrated auxiliary contacts simplify wiring and reduce panel space, a significant advantage in modern, space-constrained electrical enclosures. The 220VDC coil option is particularly suited for applications where DC control power is prevalent, such as in certain automation systems and renewable energy installations. Siemens' SIRIUS 3RT2 series is renowned for its robust construction and long operational life, positioning the 3RT2526-1BM40 as a premium choice for applications demanding high uptime and minimal maintenance. Its efficient design minimizes power consumption, contributing to overall energy savings in industrial facilities.

Key Application Scenarios

This Siemens contactor is ideally suited for motor control applications, particularly for direct-on-line starting of medium-sized three-phase motors, up to its rated current capacity. It is extensively used in manufacturing plants for controlling conveyor systems, pumps, fans, and processing machinery where reliable switching is paramount. The 2NO+2NC auxiliary contacts are invaluable for implementing interlocking logic, feedback signals to control systems (like PLCs), and alarm functions, enhancing operational safety and system diagnostics. Furthermore, its suitability for DC control circuits makes it applicable in specialized equipment and systems requiring direct current for their operation.

Practical System Integration Guidance

Integrating the Siemens 3RT2526-1BM40 into an industrial control system is a straightforward process, leveraging its user-friendly terminal design. The device features screw terminals for power connections and spring-loaded terminals for auxiliary contacts, offering flexibility and secure connections. When wiring, ensure the coil voltage (220VDC) is correctly applied to terminals A1 and A2 to prevent damage. For motor control, the main power terminals (L1, L2, L3 and T1, T2, T3) connect in series with the motor's power supply. The auxiliary contacts (13/14 for NO, 21/22 for NC) can be wired into the control circuit for interlocking or status feedback to a PLC, typically requiring a separate low-voltage control power supply. Always adhere to local electrical codes and standards during installation, and ensure proper termination of all wires.

Operation and Risk Mitigation

Proper operation of the Siemens 3RT2526-1BM40 relies on understanding its switching capabilities and electrical environment. It is designed to operate reliably within its specified voltage and current ratings, with particular attention to the DC coil voltage. Overloading the contactor beyond its AC-3 rating can lead to premature contact wear or coil failure. Potential risks include electrical shock if not installed correctly, and arcing if operated outside its intended parameters. To mitigate risks, always ensure proper grounding, use appropriately sized conductors, and implement safety interlocks. Regular inspection of terminals for tightness and signs of wear is recommended. Faulty operation, such as failure to energize or de-energize, often points to coil issues, incorrect voltage supply, or mechanical obstruction, requiring immediate investigation by qualified personnel.

Scalability & Long-Term Value

The Siemens 3RT2526-1BM40 offers significant long-term value through its compatibility with the broader SIRIUS 3RT2 ecosystem and Siemens' broader industrial automation portfolio. This enables seamless integration with other SIRIUS devices, such as overload relays and circuit breakers, for comprehensive motor protection solutions. For facilities moving towards Industry 4.0, this contactor can be integrated into smart control cabinets, acting as a fundamental component that provides status feedback and can be controlled remotely. While the contactor itself is a fixed-function device, its scalability is achieved through its integration into larger, more intelligent control architectures, supporting future upgrades and digital transformation initiatives within the plant.

Frequently Asked Questions (FAQs)

What is the function of the Siemens 3RT2526-1BM40 contactor?

This contactor acts as an electrically operated switch. It controls high-power circuits, like motors, using a low-power control signal.

The 220VDC coil allows it to be activated by a direct current voltage. Its 25A rating makes it suitable for moderate industrial loads.

It offers reliable switching for various automation tasks, ensuring operational continuity and safety in industrial settings.

Can the Siemens 3RT2526-1BM40 be used for AC motor control?

Yes, the 3RT2526-1BM40 is rated for AC-3 applications. This means it is suitable for controlling AC induction motors.

Its 25A rating at 400V AC (AC-3) ensures it can handle typical motor starting currents. The 2NO+2NC auxiliary contacts assist in motor control logic.

Always ensure the motor's power requirements are within the contactor's specified limits for safe and efficient operation.

How do the 2NO and 2NC auxiliary contacts work?

The 2 Normally Open (NO) contacts close when the coil is energized. They are used for signaling that the contactor is active.

The 2 Normally Closed (NC) contacts open when the coil is energized. They are typically used for safety interlocks or to signal the contactor is inactive.

These contacts provide essential feedback and interlocking capabilities for complex control circuits and safety systems.