Siemens 3RT6018-1AN21 High Power AC Contactor 220VAC 16A 3NO

The Siemens 3RT6018-1AN21 is a high-performance AC contactor designed for robust industrial applications. This 3-pole contactor features a 220VAC coil voltage and a rated current of 16A, making it suitable for controlling motors and other inductive loads up to 7.5 kW at 400V. Its compact S00 size and screw terminal connections facilitate straightforward integration into control panels. The inclusion of one normally open (NO) auxiliary contact enhances its control and signaling capabilities.

Product Specifications

| Feature              | Specification                               |

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

| Manufacturer         | Siemens                                     |

| Part Number          | 3RT6018-1AN21                               |

| Series               | 3RT60                                       |

| Type                 | AC Contactor                                |

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

| Rated Current (AC-3) | 16A                                         |

| Max Power (400V)     | 7.5 kW                                      |

| Number of Poles      | 3-pole                                      |

| Auxiliary Contacts   | 1 Normally Open (NO)                        |

| Terminal Type        | Screw Terminal                              |

| Size                 | S00                                         |

| Dimensions (L x W x H)| 80.00 x 50.00 x 61.00 mm                    |

| Net Weight           | 0.240 Kg                                    |

| RoHS Compliance      | Yes (Since 01.05.2012)                      |

| Product Class        | A: Standard product, stock item             |

| Approvals            | TÜV, EU Declaration of Conformity, CCC, CQC |

Core Features & Market Positioning

The Siemens 3RT6018-1AN21 stands out in the competitive landscape of industrial control components due to its proven Siemens reliability and efficient design. As a standard stock item, it offers excellent availability and a straightforward return policy, minimizing procurement risks for end-users. Its market positioning is that of a dependable, no-nonsense solution for general-purpose motor control and power switching applications. The contactor's adherence to international standards, including TÜV, EU Declaration of Conformity, and CCC, underscores its suitability for global markets and demanding industrial environments. While specific technology differentiations beyond its core function are not heavily emphasized in product literature, its robust construction and consistent performance align with Siemens' reputation for quality in automation.

Key Application Scenarios

The Siemens 3RT6018-1AN21 is ideally suited for a broad spectrum of industrial applications where reliable AC power switching is paramount. Common use cases include the direct or indirect control of three-phase motors in manufacturing, material handling, and process automation. It excels in starting and stopping pumps, fans, compressors, and conveyor systems. The inclusion of a normally open auxiliary contact allows for integration into control circuits for status signaling, interlocking, or alarm functions, further expanding its utility in complex automation setups. This contactor is a staple in control panel construction for machine tools, HVAC systems, and general industrial machinery.

Practical System Integration Guidance

Integrating the Siemens 3RT6018-1AN21 into an electrical control system is designed to be efficient. The unit features standard screw terminals for main power connections and auxiliary contacts, simplifying wiring. For motor control, it is typically wired in series with the motor power supply, controlled by a pilot device such as a push button or PLC output connected to the coil terminals (typically labeled A1 and A2). The 220VAC coil voltage requires a stable power source within this range. The single NO auxiliary contact can be wired into control logic to provide feedback on the contactor's operational status. While detailed programming examples are application-specific, users can typically use the NO contact to signal to a PLC that the motor is energized or to enable downstream control logic. Always refer to the official Siemens installation manual for detailed wiring diagrams and safety precautions.

Operation and Risk Mitigation

Safe and reliable operation of the Siemens 3RT6018-1AN21 relies on correct installation and adherence to operational parameters. The contactor is designed for AC loads within its rated capacity; attempting to switch DC loads or exceeding the 16A or 7.5kW limits can lead to premature failure or hazards. It's crucial to ensure the coil voltage precisely matches the supply (220VAC). Proper grounding of the control panel and the contactor's mounting location is essential for electrical safety. Overheating due to continuous operation at maximum load or inadequate ventilation could be a concern; ensure sufficient airflow around the installed contactor. While specific fault codes are not typically associated with contactors, failure to operate or intermittent switching could indicate coil issues, contact wear, or mechanical obstruction, necessitating inspection and potential replacement.

Scalability & Long-Term Value

The Siemens 3RT6018-1AN21, as part of the broader Siemens automation ecosystem, offers good long-term value. While this specific model is a fixed configuration, Siemens offers a wide range of contactors and related components (e.g., overload relays, soft starters) that are compatible, allowing for system expansion or upgrades. For instance, if a motor's power requirement increases, a larger Siemens contactor from a compatible series could be substituted. Its compatibility with PLC systems enables seamless integration into modern digital control architectures, supporting the move towards Industry 4.0 and IIoT solutions through data feedback via auxiliary contacts or integration with networked control modules.

Frequently Asked Questions (FAQs)

Q1: What is the primary function of the Siemens 3RT6018-1AN21 contactor?

This AC contactor serves as an electrically operated switch. It is primarily used to switch high-power AC circuits on and off.

Its main role is to control electric motors and other industrial loads reliably. The 220VAC coil activates the switching mechanism.

It is a critical component in motor control applications, ensuring safe and efficient power management in industrial settings.

Q2: Can the Siemens 3RT6018-1AN21 be used for DC applications?

No, this contactor is specifically designed for AC (Alternating Current) applications. Using it for DC (Direct Current) loads is not recommended.

DC switching has different arc characteristics that can damage AC contactor contacts. Always use contactors rated for the specific type of current.

Using the wrong type of current can lead to premature failure, equipment damage, and safety hazards.

Q3: What is the maximum power rating for the Siemens 3RT6018-1AN21?

The contactor is rated for a maximum power of 7.5 kW at 400V AC, according to AC-3 duty. This rating is for motor control applications.

It can handle a continuous current of 16A, but the power rating is a more significant factor for motor loads. Always check the specific application requirements.

Exceeding the rated power can cause overheating, contact welding, and potential failure of the device.

Q4: How many auxiliary contacts does the Siemens 3RT6018-1AN21 have?

This specific model, the 3RT6018-1AN21, comes with one normally open (NO) auxiliary contact. These contacts are used for control or signaling purposes.

The NO contact is closed when the main contactor coil is energized. It can be used to send a status signal or enable other control functions.

It is important to note that this is a single auxiliary contact; for applications requiring normally closed (NC) or additional NO contacts, a different model or an add-on block might be needed.

Q5: What does the coil voltage of 220VAC signify?

The 220VAC coil voltage indicates the power supply required to energize the contactor's coil. This causes the main contacts to close.

This voltage level (220 Volts AC) is common in many industrial and commercial power systems. Ensure your control circuit provides this specific voltage.

Using a different voltage to energize the coil will prevent the contactor from operating correctly or could damage it.

Q6: What is the significance of the S00 size rating?

The S00 size designation refers to the physical dimensions and power handling capacity of the contactor. It indicates a compact form factor.

Size S00 contactors are typically used for lower power motor applications, such as those up to 7.5 kW. This makes them ideal for space-constrained control panels.

Its S00 sizing means it is designed to be smaller than larger contactor sizes like S2 or S3, allowing for denser panel designs.

Q7: Is the Siemens 3RT6018-1AN21 suitable for frequent switching cycles?

Yes, Siemens contactors like the 3RT6018-1AN21 are engineered for industrial use, which often involves frequent switching. Their robust construction ensures longevity.

However, the electrical lifespan (number of operations) depends on the load type and switching frequency. For very high cycle applications, consider specific duty ratings.

For applications with extremely high switching demands, dedicated contactor relays or solid-state relays might offer superior performance and longevity.

Q8: Can I add more auxiliary contacts to the Siemens 3RT6018-1AN21?

Yes, Siemens often allows for the addition of auxiliary contact blocks to their contactors. Check for compatibility with add-on blocks.

Additional blocks can provide more NO or NC contacts, expanding control and signaling capabilities. These are typically front-mounted.

Ensure any add-on auxiliary contact block is specifically designed for the 3RT60 series and the S00 size for proper fit and function.

Q9: Where is the Siemens 3RT6018-1AN21 manufactured?

According to product data, the country of origin for the 3RT6018-1AN21 is China. This is common for many industrial components.

Siemens maintains strict quality control standards across all its manufacturing locations worldwide. The product adheres to global standards.

Despite the manufacturing origin, the product carries the Siemens brand reputation for quality and reliability.

Q10: What documentation is available for the Siemens 3RT6018-1AN21?

Numerous documents are available, including datasheets, installation instructions, and general product approvals. These can be found on the Siemens SiePortal.

These documents provide critical technical specifications, safety information, and integration guidelines. They are essential for proper installation and operation.

Certifications like TÜV and EU Declaration of Conformity are also documented, confirming its compliance with international safety and quality standards.