Siemens SQM50.381A2 Basic Linear Actuator

The Siemens SQM50.381A2 Basic Linear Actuator delivers robust and reliable performance for critical HVAC and industrial automation applications. This actuator is distinguished by its precise control, durable construction, and straightforward integration capabilities. Key technical specifications include an operating voltage of 24V AC, a stroke length of 20mm, and an output force of 100N, enabling accurate positioning of dampers and valves. Its compact design and IP54 protection rating ensure suitability for diverse environmental conditions.

Siemens SQM50.381A2: Product Specifications

| Feature               | Specification                               |

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

| Model                 | SQM50.381A2                                 |

| Operating Voltage     | 24V AC                                      |

| Stroke                | 20mm                                        |

| Force                 | 100N                                        |

| Control Signal        | 3-point (Open/Close)                        |

| Ambient Temperature   | -20 to +50 °C                               |

| Protection Rating     | IP54                                        |

| Auxiliary Switches    | Not included                                |

| Manual Override       | Yes                                         |

Core Features & Market Positioning

The Siemens SQM50.381A2 excels in applications demanding precise flow or air control. Its market positioning is defined by Siemens' reputation for quality and reliability in automation technology. The actuator's direct-acting 3-point control, offering definitive open and close signals, simplifies integration with standard control systems. Unlike more complex variable position actuators, the SQM50.381A2 is engineered for applications where simple on/off or two-position control is sufficient, making it a cost-effective and robust solution. Its built-in manual override is a significant advantage for maintenance and emergency operations, enhancing system uptime and serviceability.

Key Application Scenarios

This linear actuator finds its primary utility in Building Management Systems (BMS) and HVAC control loops. It is ideally suited for precise actuation of air dampers in ventilation systems, ensuring optimal airflow and energy efficiency. Furthermore, the SQM50.381A2 is frequently employed for controlling water or steam valves in heating and cooling circuits, maintaining desired temperatures and system performance. Its robust design and IP54 rating make it suitable for installation in mechanical rooms and other industrial environments where dust and moisture may be present. Common user search queries often revolve around its use in VAV (Variable Air Volume) systems and zone control.

Practical System Integration Guidance

Integrating the Siemens SQM50.381A2 into existing control infrastructure is streamlined due to its standard 3-point control interface. Connection typically involves wiring the actuator directly to the terminals of a compatible controller or relay output. The power supply requires a stable 24V AC source. For installation, ensure the actuator is mounted securely to the damper or valve linkage, allowing for full range of motion without obstruction. The manual override can be engaged by turning the manual adjustment knob, allowing for direct mechanical adjustment of the connected device.

Operation and Risk Mitigation

Operating the SQM50.381A2 involves ensuring it receives the correct 3-point control signals from the automation system. The actuator will move to its fully open or fully closed position based on these signals. Its inherent design minimizes operational risks; however, users should always confirm proper mechanical linkage to prevent binding or excessive force. In the event of power loss, the manual override allows for safe positioning of the connected damper or valve. While the SQM50.381A2 is designed for long service life, regular inspection of the linkage and mounting points is recommended to prevent potential mechanical failures.

Scalability & Long-Term Value

While the SQM50.381A2 is a basic actuator, its value lies in its foundational reliability for essential control tasks. It integrates seamlessly with a wide array of Siemens and third-party control systems that support 3-point signaling. For applications requiring variable positioning or more advanced feedback, higher-tier Siemens actuators would be considered. However, for straightforward on/off or two-position control needs, the SQM50.381A2 offers exceptional longevity and dependable performance, contributing to the overall operational efficiency and reduced maintenance costs of the system it serves.

FAQs

What is the typical application for a Siemens SQM50.381A2?

This actuator is primarily used in HVAC systems. It controls dampers and valves for airflow and temperature regulation.

It ensures precise positioning for optimal building climate control. Its robustness suits industrial environments.

The SQM50.381A2 is ideal for applications needing simple two-position control.

How do I wire the Siemens SQM50.381A2 actuator?

Connect the actuator to a 24V AC power supply. Use the three control terminals for 3-point signaling.

Ensure correct polarity for open and close commands. Refer to the specific controller's wiring diagram.

Proper wiring prevents actuator damage and ensures correct operation.

What is the force output of the SQM50.381A2?

The actuator provides a force of 100 Newtons. This force is sufficient for many standard damper and valve applications.

It ensures reliable movement against moderate resistance. Always verify force requirements for your specific application.

This force rating is crucial for actuator selection.

Can the SQM50.381A2 be used for proportional control?

No, the SQM50.381A2 is designed for 3-point (Open/Close) control only. It does not support proportional or modulating signals.

For proportional control, a different Siemens actuator model is required. These models accept analog control signals.

This actuator is best suited for simple on/off or two-position applications.

What is the stroke length of the SQM50.381A2?

The SQM50.381A2 features a linear stroke of 20 millimeters. This stroke length is standard for many damper and valve operations.

It allows for sufficient travel to fully open or close connected devices. Ensure your linkage mechanism accommodates this stroke.

The 20mm stroke is a key parameter for physical integration.

Does the Siemens SQM50.381A2 have a manual override?

Yes, the SQM50.381A2 includes a manual adjustment knob. This allows for direct mechanical operation.

The manual override is essential for service and emergency situations. It enables positioning without power.

This feature enhances system maintainability and safety.

What is the environmental protection rating of this actuator?

The Siemens SQM50.381A2 has an IP54 protection rating. This means it is protected against dust and splashing water.

This rating ensures reliable operation in less than ideal environments. It is suitable for mechanical rooms and general plant areas.

IP54 protection adds to its versatility and durability.

What operating voltage does the SQM50.381A2 require?

The actuator operates on a 24 Volt AC power supply. Ensure your control system provides stable AC voltage.

Using an incorrect voltage can damage the actuator. Always verify the power source specifications.

24V AC is a common standard for HVAC controls.

How does the 3-point control signal work?

A 3-point control signal uses three wires: two for power and one each for "open" and "close" commands. The controller sends a signal to open or close the actuator.

When the controller energizes the "open" terminal, the actuator moves to the open position. De-energizing this and energizing "close" moves it to the closed position.

This simple switching logic makes integration straightforward.

What is the ambient temperature range for operation?

The SQM50.381A2 can operate in temperatures from -20 to +50 degrees Celsius. This wide range supports diverse climate conditions.

Ensure the installation location stays within these limits for optimal performance. Extreme temperatures can affect actuator lifespan.

This operational range is crucial for system design.