Siemens 3RT5046-1AN20 Double Auxiliary Coil Contactor 220VAC 95A 3NO

The Siemens 3RT5046-1AN20 is a robust 3-pole, size S3 contactor designed for demanding industrial applications. This unit features a 220VAC coil and a significant 95A rating under AC-3 load conditions, making it suitable for motor control up to 45 kW at 400V. Its durable construction and adherence to IEC standards ensure reliable performance in harsh environments. Key advantages include its compact size (S3), screw terminals for secure connections, and broad compatibility within the Siemens SIRIUS line. The Siemens 3RT5046-1AN20 is an active product, ensuring ongoing support and availability.

Product Specifications

| Feature                     | Specification                               |

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

| Manufacturer                | Siemens                                     |

| Product Number              | 3RT5046-1AN20                               |

| Product Family              | SIRIUS                                      |

| Type                        | 3RT50                                       |

| Number of Poles             | 3                                           |

| Rated Operational Current (AC-3) | 95 A (at 400 V)                             |

| Rated Operational Power (AC-3) | 45 kW (at 400 V)                            |

| Coil Voltage                | 220 VAC (50/60 Hz)                          |

| Terminal Type               | Screw Terminals                             |

| Size                        | S3                                          |

| Enclosure Rating            | IP20 (basic unit)                           |

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

| Net Weight                  | 1.840 Kg                                    |

| Dimensions (L x W x H)      | 165.00 x 160.00 x 80.00 mm                  |

| Compliance                  | RoHS directive compliant (since 03/01/2017) |

Core Features & Market Positioning

The Siemens 3RT5046-1AN20 distinguishes itself through its high current carrying capacity and integration into the comprehensive SIRIUS modular system. This contactor is engineered for superior reliability and longevity, making it a preferred choice for engineers and system integrators prioritizing robust motor control solutions. Its IEC rating signifies adherence to international standards, assuring performance and safety. The ability to integrate seamlessly with other SIRIUS components further enhances its market position as a flexible and scalable solution for diverse industrial automation needs. The inclusion of screw terminals provides a secure and trusted connection method, crucial for preventing faults in high-vibration environments.

Key Application Scenarios

This Siemens 3RT5046-1AN20 contactor is ideally suited for controlling and switching three-phase motors across various industrial sectors. Common applications include:

  Manufacturing and Processing: Direct on-line (DOL) starting of motors for conveyors, pumps, fans, compressors, and machine tools.  Material Handling: Operation of cranes, hoists, and automated storage systems where reliable start/stop functionality is paramount.  HVAC Systems: Control of large fans, chillers, and air handling units in commercial and industrial buildings.  Water Treatment: Operation of pumps for water circulation, aeration, and filtration processes.

Its high AC-3 rating ensures it can handle the typical inductive loads presented by motor starting currents effectively and safely.

Practical System Integration Guidance

Integrating the Siemens 3RT5046-1AN20 into an industrial control system is straightforward, leveraging its standard DIN rail mounting capabilities and screw terminal connections. For DIN rail installation, ensure the contactor is mounted with the spring mechanism engaging correctly with the rail, often requiring a downward push on the spring end while lifting the opposite side. The main circuit terminals are designed for secure screw connections, accommodating appropriate cable sizes for the 95A rating. For the control circuit, the 220VAC coil connects to A1 and A2 terminals. It's crucial to verify the correct voltage supply to prevent coil damage. While this model is a standard 3NO (Normally Open) contactor, auxiliary contact blocks can be added for additional control or signaling functions, enhancing system feedback and interlocks. Always consult the official Siemens documentation for detailed wiring diagrams and safety guidelines specific to your application.

Operation and Risk Mitigation

Proper operation of the Siemens 3RT5046-1AN20 involves supplying the correct 220VAC to the coil (terminals A1/A2) to energize the main contacts, allowing current to flow through the three poles. During operation, the contactor should be protected from excessive dust, moisture, and extreme temperatures outside its specified range (-25°C to +60°C) to ensure longevity and prevent failure. Risk mitigation primarily focuses on electrical safety. Ensure proper lockout/tagout procedures are followed during maintenance. The contactor itself is designed with safety in mind, offering touch-proof terminals. Potential issues like coil failure or contact welding can occur under extreme overload or frequent switching beyond its rating. Regular inspections and adherence to the specified duty cycle are key to preventing such failures. Troubleshooting often involves checking the coil voltage, verifying control circuit integrity, and inspecting main contacts for signs of wear or damage.

Scalability & Long-Term Value

The Siemens 3RT5046-1AN20 offers significant long-term value due to its integration within the scalable SIRIUS product line. This allows for future expansion and adaptation of control systems. For instance, additional auxiliary contacts can be easily added to accommodate evolving system requirements, providing more feedback or control points without replacing the main contactor. Compatibility with other SIRIUS components, such as overload relays and soft starters, facilitates the creation of complete motor control solutions. This modularity ensures that as automation demands grow, the existing infrastructure can be leveraged, reducing upgrade costs and minimizing system downtime. The active product status also guarantees continued availability and support from Siemens, securing the long-term viability of installations utilizing this contactor.

Frequently Asked Questions (FAQs)

Q1: What is the main function of the Siemens 3RT5046-1AN20 contactor?

The Siemens 3RT5046-1AN20 is an industrial power contactor. Its primary role is to switch electrical power to a load, most commonly a three-phase motor. It acts as a heavy-duty electrically operated switch.

It allows for remote control and automation of electrical circuits. The contactor uses a 220VAC coil to electromagnetically close its main power contacts. This enables precise starting and stopping of machinery.

By using a contactor, users can control high-power circuits with low-power control signals. This enhances safety and simplifies control system design.

Q2: Can the Siemens 3RT5046-1AN20 be used for DC motor control?

No, this specific contactor, the Siemens 3RT5046-1AN20, is designed for AC applications only. It features an AC coil voltage and its contact ratings are specified for AC load types like AC-3.

Using this contactor for DC circuits is not recommended and can lead to premature failure. DC switching presents different arc characteristics that these AC-rated contacts are not built to handle.

For DC motor control, a dedicated DC contactor or a suitable relay with appropriate DC ratings must be used. Always check the product specifications for intended voltage and current types.

Q3: What is the maximum motor size this contactor can control?

The Siemens 3RT5046-1AN20 is rated for 45 kW at 400V under AC-3 duty. This is the standard rating for motor control applications.

This power rating translates to approximately 60 horsepower for a 400V motor. Always consider the motor's full load current and starting characteristics.

Consulting motor nameplate data and comparing it against the contactor's AC-3 rating is essential for safe and reliable operation.

Q4: How do I wire the Siemens 3RT5046-1AN20?

The main power terminals for the three poles are clearly marked (typically L1, L2, L3 for line side and T1, T2, T3 for load side). Connect your power source to the line terminals and your motor or load to the load terminals using appropriate gauge wiring.

The control coil is energized by applying 220VAC to terminals A1 and A2. Ensure the control voltage source matches the coil's rated voltage precisely.

For additional control or signaling, auxiliary contact blocks can be added to the front or side of the contactor. These typically include Normally Open (NO) and Normally Closed (NC) contacts.

Q5: What does the "S3" size designation mean for the 3RT5046-1AN20?

The "S3" designation refers to the physical size and power handling capability of the contactor within the Siemens SIRIUS sizing system. Larger sizes like S3 indicate a higher current and power rating.

Size S3 contactors are generally for higher amperage applications, such as controlling larger motors or higher power loads. This size typically accommodates the robust internal components needed for such ratings.

It is important for system design to select contactors of the correct size to ensure they meet the electrical demands of the application without overheating or premature failure.

Q6: Can I add auxiliary contacts to the Siemens 3RT5046-1AN20?

Yes, the Siemens 3RT5046-1AN20 is designed to accommodate auxiliary contact blocks. These can typically be mounted to the front or side of the main contactor body.

These auxiliary contacts provide additional switching capabilities for control circuits, signaling, or interlocking functions. Common configurations include normally open (NO) and normally closed (NC) contacts.

Always ensure that the auxiliary contact blocks are compatible with the specific 3RT50 series contactor and that they are securely attached according to the manufacturer's instructions.

Q7: What is the significance of the "double auxiliary coil" in the product name?

The "double auxiliary coil" phrasing in the product title may be a misunderstanding or a non-standard description. This specific model, Siemens 3RT5046-1AN20, typically refers to a single coil operating at 220VAC.

Standard contactors use a single coil to create the magnetic field for switching. If a configuration implies two coils, it might refer to a specialized product or a misunderstanding of how auxiliary contacts function.

Auxiliary contacts are separate from the main coil; they are triggered by the main contactor's operation to provide additional N/O or N/C switching points.

Q8: What are the environmental operating limits for this contactor?

The Siemens 3RT5046-1AN20 has a specified operating temperature range of -25°C to +60°C. It is also rated for a maximum installation altitude of 2,000 meters above sea level.

Beyond these limits, performance can be compromised. Higher temperatures can lead to overheating and reduced lifespan, while extreme cold might affect mechanical components.

Ensure the contactor is installed in a location that respects these environmental parameters to guarantee its operational reliability and longevity.

Q9: Is the Siemens 3RT5046-1AN20 suitable for frequent switching applications?

The Siemens 3RT5046-1AN20 has a high mechanical service life of 10 million switching cycles. However, its electrical switching capacity depends on the load type.

For AC-3 duty (motor starting), it has a maximum switching frequency of 850 cycles per hour. For AC-1 duty (resistive loads), this can increase to 900 cycles per hour.

Operating beyond these specified frequencies, especially under AC-3 conditions, can significantly reduce the contactor's electrical lifespan due to increased arcing and wear.

Q10: Where can I find the official datasheet or documentation for the Siemens 3RT5046-1AN20?

Official documentation, including detailed datasheets and operating instructions, can typically be found on the Siemens Industry Online Support portal or through the Siemens SiePortal platform.

These resources provide comprehensive technical specifications, wiring diagrams, dimensional drawings, and safety information. They are crucial for correct installation and operation.

Product pages on authorized distributor websites also often link to or provide downloadable PDFs of the official Siemens documentation for this specific part number.