​Siemens 3RT6027-1AN20 AC contactor

Siemens 3RT6027-1AN20 is an AC contactor suitable for the field of industrial automation. It belongs to the Sirius 3RT6 series and is mainly used to control the start, stop and operation of electric motors.

 Core Technical Parameters

1. Rated Current and Power

- Under AC-3 duty cycle (motor load), the rated current is 32A at 400V, which can control a 15kW three-phase asynchronous motor.

- Under AC-1 duty cycle (non-inductive or slightly inductive load), the maximum current can reach 50A at an ambient temperature of 40°C.

2. Coil Parameters

The coil voltage is AC 220V with a frequency of 50/60Hz. The power consumption of the control circuit is as low as 2.62W (no-load condition), ensuring energy-efficient operation.

3. Contact Configuration

- **Main contacts**: 3-pole normally open (3NO), supporting screw terminal connection and adaptable to 10mm² wires.

- **Auxiliary contacts**: 1 normally open (NO) + 1 normally closed (NC), used for signal feedback or interlocking functions in the control circuit.

4. Mechanical and Electrical Life

- Mechanical life: Up to 10 million operations.

- Electrical life: Approximately 200,000 operations under AC-3 duty cycle, suitable for long-term and frequent operations.

 5. Environmental Adaptability

- Operating temperature range: -25°C to +60°C

- Storage temperature range: -55°C to +80°C

- Protection class: IP20 (protection against finger contact), suitable for general industrial environments.

Certifications and Standards

- **CE Certification**: Complies with the requirements of the EU Low Voltage Directive (LVD) and Electromagnetic Compatibility (EMC).

- **RoHS Compliance**: Products manufactured since May 2012 comply with the EU RoHS Directive, ensuring environmental friendliness.

Application Scenarios

1. Motor Control

Widely used for start-stop control of equipment such as fans, pumps and compressors, and supports typical circuits like star-delta reduced-voltage starting and forward-reverse control. For example, in building electrical systems, it can be used for the electrical control of elevators and air conditioning units.

2. Industrial Automation Production Lines

It cooperates with equipment such as PLCs (Programmable Logic Controllers) and sensors to realize the logical control of automated production processes and ensure the continuous operation of equipment.

 3. Alternative Solutions

It can replace the earlier Siemens model 3RT1027 and is compatible with third-party contactors (e.g., Schneider LC1D32). However, attention should be paid to matching the installation dimensions and contact capacity.

Installation and Maintenance

1. Installation Method

Supports 35mm standard DIN rail mounting or screw fixing. It has a size of S0 (width 45mm), which saves space in the control cabinet.

2. Matching Accessories

- **Thermal overload relay**: Model 3RU6126-4CB0 (setting current 17-22A) is recommended for motor overload protection.

- **Auxiliary contact module**: Can be expanded to 4 auxiliary contacts (e.g., 3RT7921) to meet complex control requirements.

 3. Maintenance Recommendations

Regularly check the wear condition of contacts, clean dust, and ensure that the terminal blocks are tight. Replace the contacts when their wear exceeds 1/3 of the original thickness.

 Market and Price

1. Supply Status

It will remain an active product in 2025. In-stock sales are available via WhatsApp: 0086-13811255435. The unit price is approximately 68-135 RMB, which varies depending on the purchase quantity and channel.

 2. After-Sales Service

Siemens provides a 1-year warranty. Technical support and maintenance services can be obtained through official channels.

 Precautions

1. Voltage Matching

Ensure that the coil voltage is consistent with the control circuit to avoid damage caused by incorrect connection.

2. Derated Operation

When the ambient temperature exceeds 40°C, derated operation is required in accordance with the manual (e.g., the AC-3 current is reduced to 27A at 60°C).

3. Short-Circuit Protection

It must be used with an appropriate circuit breaker (e.g., Siemens 5SY series) to ensure rapid breaking in case of a short circuit.