Siemens 3RT5036-1BB40 Contactor with Auxiliary Contacts 24VDC 50A 3NO

The Siemens 3RT5036-1BB40 Contactor is a robust 24VDC, 50A device featuring 3 normally open (NO) auxiliary contacts, designed for demanding industrial control applications. Its key advantages lie in its reliability, compact design, and efficient operation, making it a preferred choice for motor control and power switching. The product boasts a high switching capacity and a long electrical lifespan, ensuring consistent performance in harsh environments.

Product Specifications

| Feature                  | Specification                               |

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

| Product Type             | Power Contactor                             |

| Siemens Order Number     | 3RT5036-1BB40                               |

| Coil Voltage             | 24V DC                                      |

| Rated Operational Current | 50 A                                        |

| Number of NO Contacts    | 3                                           |

| Number of NC Contacts    | 0                                           |

| Auxiliary Contact Type   | 3 NO                                        |

| Mounting Type            | Rail-mount (35mm DIN rail)                  |

| Protection Rating        | IP20                                        |

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

| Electrical Life          | Up to 10 million switching cycles           |

| Mechanical Life          | Up to 30 million switching cycles           |

| Terminal Type            | Screw Terminals                             |

| Standards                | IEC 60947-4-1, VDE 0660 Part 102            |

Core Features & Market Positioning

The Siemens 3RT5036-1BB40 distinguishes itself through its proven Siemens reliability and adherence to stringent international standards like IEC 60947-4-1. Its direct load wiring capability simplifies installation, reducing labor costs and potential error points. This contactor is positioned as a dependable solution for engineers seeking high performance in essential switching functions without unnecessary complexity. The integrated auxiliary contacts provide immediate status feedback, crucial for system monitoring and automation integration. Compared to other contactors in its class, the 3RT5036-1BB40 offers a balanced profile of durability, power handling, and ease of use.

Key Application Scenarios

This Siemens contactor is ideally suited for direct on-line motor starting applications, particularly in scenarios requiring a 24VDC control voltage. Common uses include controlling pumps, fans, conveyor systems, and other industrial machinery where precise and reliable power switching is paramount. Its robust construction makes it suitable for environments with moderate dust and humidity. Engineers frequently specify the 3RT5036-1BB40 for its straightforward integration into existing control panels and its compatibility with programmable logic controllers (PLCs) for automated operations.

Practical System Integration Guidance

Integrating the Siemens 3RT5036-1BB40 involves straightforward wiring. The main power terminals accommodate load and line connections for the 50A circuit, while the coil terminals require a stable 24VDC supply. The three NO auxiliary contacts can be wired into control circuits for feedback signals, indicating the contactor's energized state. For motor control, it's often paired with overload relays to provide comprehensive protection. Ensure proper torque is applied to screw terminals to prevent loose connections, which can lead to operational failures.

Operation and Risk Mitigation

Operating the Siemens 3RT5036-1BB40 is designed for safety and simplicity. The coil operates on a low voltage (24VDC), minimizing shock hazards during maintenance. It's crucial to ensure the contactor's rating (50A) is not exceeded to prevent overheating and potential damage. Always disconnect power before performing any wiring or maintenance. If the contactor fails to operate, check the 24VDC coil supply and verify that no overload conditions exist in the main circuit. Consistent troubleshooting often involves checking for proper coil energization and clear auxiliary contact paths.

Scalability & Long-Term Value

The Siemens 3RT5036-1BB40 provides excellent long-term value through its durability and compatibility with Siemens' broader industrial control ecosystem. While this specific model is fixed in its configuration, it can be part of larger, scalable systems. Its integration with PLCs allows for sophisticated control strategies and data acquisition, aligning with Industry 4.0 initiatives. When planning for system expansion, the reliability of components like the 3RT5036-1BB40 ensures a stable foundation for future upgrades or the addition of more complex automation features.

FAQs

What is the coil voltage of the Siemens 3RT5036-1BB40?

The Siemens 3RT5036-1BB40 operates with a coil voltage of 24V DC. This low voltage is standard for many control systems, enhancing safety during installation and maintenance.

This 24V DC coil is designed for reliable activation of the contactor's switching mechanism. It ensures that the power circuit controlled by the contactor is engaged or disengaged precisely when the control signal is applied or removed.

Ensuring a stable and correct 24V DC power supply to the coil is critical for the proper functioning of the entire system. Fluctuations or incorrect voltage can lead to unreliable operation or premature failure of the contactor.

What is the maximum current rating for the Siemens 3RT5036-1BB40?

This contactor is rated for a maximum operational current of 50 Amperes. This rating specifies the continuous current it can safely handle in the main power circuit under standard operating conditions.

Exceeding the 50A rating can lead to overheating of the contactor's internal components, potentially causing damage, reduced lifespan, or even failure. It's essential to match the contactor's rating to the load it will control.

For loads that may experience transient current peaks above 50A, such as motor startups, it is advisable to consult motor starting current data and consider oversizing the contactor or using appropriate overload protection to safeguard it.

How many auxiliary contacts does the Siemens 3RT5036-1BB40 have, and what type are they?

The Siemens 3RT5036-1BB40 is equipped with three auxiliary contacts. All three of these auxiliary contacts are normally open (NO) in their default state.

Normally open contacts remain open when the main coil of the contactor is de-energized. They close when the coil is energized, allowing them to be used for signaling, interlocking, or initiating other control functions.

These three NO contacts offer significant flexibility for monitoring the contactor's status and integrating it into complex control logic, providing feedback on whether the main circuit is active.

Can the Siemens 3RT5036-1BB40 be mounted on a standard DIN rail?

Yes, the Siemens 3RT5036-1BB40 is designed for easy mounting onto a standard 35mm DIN rail. This is a common and convenient method for installing industrial electrical components.

The DIN rail mounting system simplifies installation, allows for quick removal and replacement, and ensures consistent spacing and alignment of components within control cabinets.

Using a DIN rail provides a secure and organized way to house the contactor, contributing to a neat and professional electrical panel layout.

What is the typical application for this type of contactor?

This contactor is typically used for direct on-line motor starting and control. It's suitable for switching inductive loads like motors for pumps, fans, and conveyors.

Its 24V DC coil voltage makes it ideal for systems where low-voltage DC control is standard, often found in automation systems with PLCs.

The 50A rating and 3NO auxiliary contacts provide a reliable solution for basic to moderately complex industrial power switching and control feedback needs.

What standards does the Siemens 3RT5036-1BB40 comply with?

The Siemens 3RT5036-1BB40 complies with key international standards for electrical equipment. It adheres to IEC 60947-4-1 and VDE 0660 Part 102.

These standards ensure that the contactor meets rigorous requirements for safety, performance, and reliability in industrial applications. Compliance signifies a high level of quality and interoperability.

Meeting these certifications means the product has undergone thorough testing to guarantee its suitability for switching applications in diverse industrial environments.

What is the electrical life expectancy of this contactor?

The electrical life expectancy of the Siemens 3RT5036-1BB40 can be up to 10 million switching cycles. This is a measure of its durability under electrical load.

This high number of switching cycles indicates its suitability for applications with frequent operation where long-term reliability is essential.

Actual life expectancy can vary based on operating conditions, load type, and switching frequency, but the specified rating provides a strong benchmark for its robust design.

Does this contactor require an external overload relay?

While this contactor can be used independently for basic switching, it is often paired with an external overload relay for comprehensive motor protection. The contactor handles the switching, while the relay provides overcurrent protection.

Overload relays protect the motor and the circuit from damage due to overcurrents caused by conditions like overloads, phase loss, or short circuits. They are crucial for preventing costly equipment failure.

The Siemens 3RT5036-1BB40 itself does not have integrated overload protection; therefore, for motor applications, specifying and wiring an appropriate overload relay is a standard and recommended practice.

What is the IP rating of the Siemens 3RT5036-1BB40?

The Siemens 3RT5036-1BB40 has an IP20 protection rating. This signifies that it is protected against solid objects greater than 12.5 mm in diameter and offers no specific protection against liquids.

IP20 rating means the contactor is intended for use in environments where it is not exposed to direct water or excessive moisture. It typically requires installation within an enclosure for adequate protection.

This rating is common for control components installed inside cabinets or enclosures, where they are shielded from accidental contact and environmental hazards.

Can this contactor be used in extreme temperature environments?

The Siemens 3RT5036-1BB40 is rated for operation within an ambient temperature range of -25 to +60 °C. This broad range covers most typical industrial operating conditions.

Operating the contactor outside this specified temperature range can compromise its performance and lifespan. Extreme cold can affect material properties, while extreme heat can lead to overheating.

Proper ventilation and environmental control within the control cabinet are important to ensure the contactor operates within its specified temperature limits and maintains its reliability.