Siemens 3RT6027-1AL20 Heavy Duty Industrial Coil Contactor 230VAC 32A 3NO

The Siemens 3RT6027-1AL20 is a robust 230VAC, 32A, 3NO heavy-duty industrial coil contactor engineered for demanding electrical control applications. Its primary advantages lie in its superior reliability, compact design, and adherence to stringent international standards, making it a cornerstone for safe and efficient motor control and power switching. This contactor excels in environments requiring frequent switching operations and high inductive loads, ensuring consistent performance and longevity. Key technical parameters include a 32A rated operational current, 230VAC coil voltage, and three normally open (NO) auxiliary contacts, all housed within a DIN rail mountable form factor.

Product Specifications

| Feature                 | Specification                                   |

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

| Product Type            | Contactor                                       |

| Series                  | 3RT                                             |

| Model Number            | 3RT6027-1AL20                                   |

| Rated Operational Current | 32 A                                            |

| Coil Voltage            | 230 VAC                                         |

| Number of Poles         | 3                                               |

| Number of NO Contacts   | 3                                               |

| Mounting Type           | DIN rail                                        |

| Enclosure Type          | IP20 (finger-safe)                              |

| Terminal Type           | Screw terminals                                 |

| Standards               | IEC 60947, VDE 0660, UL, CSA                      |

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

| Ambient Humidity        | 10-90% non-condensing                           |

Core Features & Market Positioning

The Siemens 3RT6027-1AL20 distinguishes itself through its Siemens-engineered reliability, a critical factor in industrial settings where downtime is costly. Its robust construction ensures a long operational lifespan, even under continuous duty cycles. The 3RT series is renowned for its compact footprint, allowing for significant space savings in control panels compared to older or less integrated solutions. Furthermore, its compliance with IEC, VDE, UL, and CSA standards positions it as a globally accepted component for a wide array of industrial projects, offering peace of mind to engineers and system integrators. This combination of durability, space efficiency, and broad compliance makes the 3RT6027-1AL20 a preferred choice for applications demanding high performance and dependable operation.

Key Application Scenarios

This heavy-duty contactor is ideally suited for direct-on-line (DOL) starting of three-phase motors up to 15 kW at 400V, a common requirement in manufacturing plants, water treatment facilities, and HVAC systems. Its robust design also makes it an excellent choice for controlling heating elements, capacitor banks, and other high-power inductive or resistive loads that demand frequent and reliable switching. The 3RT6027-1AL20 finds extensive use in pump control, conveyor systems, and general industrial automation where consistent power delivery and precise load management are paramount. Its ability to handle challenging switching conditions ensures operational continuity across diverse industrial environments.

Practical System Integration Guidance

Integrating the Siemens 3RT6027-1AL20 into an industrial control system is straightforward, primarily due to its standard DIN rail mounting and accessible screw terminals. For motor control applications, it is typically wired in series with the motor's power supply, controlled by a pilot circuit energized by the 230VAC coil. Ensuring correct wiring is crucial: line voltage is connected to the main power terminals (L1, L2, L3), and the motor connects to the load terminals (T1, T2, T3). The control circuit connects to the coil terminals (A1, A2) for actuation. For installations requiring additional control or feedback signals, the auxiliary contacts can be integrated into the PLC or control logic. Proper earthing and adherence to local electrical codes are mandatory for safe operation.

Operation and Risk Mitigation

The Siemens 3RT6027-1AL20 operates by using the 230VAC coil voltage to energize an electromagnet, which in turn closes the main power contacts, establishing a circuit for the connected load. To mitigate operational risks, ensure the contactor is correctly sized for the load and that the supply voltage matches the coil rating precisely. Overloading the contactor beyond its 32A rating can lead to premature failure of the contacts and internal components. Always disconnect power before performing any maintenance or wiring. In case of erratic operation or failure to switch, inspect the coil for continuity, check for physical damage to the contacts, and verify that control voltage is being applied correctly. Ensure proper ventilation around the contactor to prevent overheating.

Scalability & Long-Term Value

The Siemens 3RT6027-1AL20 offers significant long-term value through its compatibility with Siemens' broader industrial automation portfolio. It integrates seamlessly with SIVACON and ALPHA control systems, allowing for easy expansion and modernization of existing infrastructure. While this specific model is designed for direct control, its robust build quality means a longer service life, reducing the frequency of replacements. For evolving IIoT and Industry 4.0 initiatives, contactors like the 3RT6027-1AL20 can be integrated with smart sensors and communication modules, enabling remote monitoring of operational status and predictive maintenance, thereby enhancing system intelligence and operational efficiency.

Frequently Asked Questions

What is the maximum motor power this contactor can control?

The Siemens 3RT6027-1AL20 is rated for 32A at 400V. This typically translates to control of three-phase motors up to 15 kW. Always consult the motor's full load current (FLC) rating and relevant derating factors for precise sizing.

This contactor's robust 32A rating makes it suitable for many industrial motor applications. Precise power calculations depend on motor efficiency and operating voltage.

Verify your motor's specific current draw against the contactor's 32A limit for optimal performance and safety.

Can this contactor be used with a 110VAC control system?

No, this specific model, the 3RT6027-1AL20, is designed exclusively for a 230VAC coil voltage. Using a different voltage can damage the coil or prevent proper operation.

Siemens offers various contactor models with different coil voltages to suit diverse control system requirements. Always check the product's specifications carefully.

If your system uses 110VAC, you would need to select a Siemens contactor with a 110VAC coil, such as a different variant within the 3RT series or a comparable industrial contactor.

How do I wire the Siemens 3RT6027-1AL20 for a simple motor starter?

Connect the incoming power supply (L1, L2, L3) to the main terminals. Wire the motor leads (T1, T2, T3) to the corresponding load terminals. Energize the coil (A1, A2) with 230VAC to close the contacts.

A basic motor starter circuit uses a start/stop push-button arrangement to control the coil voltage applied to A1/A2. Ensure interlocking for safety in reversible applications.

Proper grounding of the motor and the contactor chassis is essential for safety. Adhere to local electrical codes and standards during installation.