Weishaupt Burner Servomotor STE 4.5

Product Details

The STE series (often designated as STE...) is a range of compact servomotors manufactured by Siemens (formerly Landis & Staefa). These actuators are specifically designed for air damper control in small to medium-sized burners and are frequently found on specialized burner brands like Elco, Weishaupt, and Riello. The STE series is distinct from the SQN series due to its more rectangular, slim profile and its use in specific electronic ratio control applications. 1. Key Models and Versions The STE series is primarily categorized by its control type (Analog/Relay vs. Digital/Bus) and the specific burner it was engineered for. Model Series Control Type Typical Application STE 4.5 3-position / Relay Basic 2-stage or modulating burners. STE 50 Electronic / Analog High-precision air/fuel ratio control. STE 4.5 B0.36 Specialized Bus Used specifically with Elco/Cuenod burner controllers. 2. Technical Specifications Parameter Specification Voltage $24\text{V DC}$ (Internal) or $230\text{V AC}$ (via controller) Torque $1.2\text{ Nm}$ to $6.0\text{ Nm}$ (depending on gear ratio) Running Time $4.5\text{ s}$, $12\text{ s}$, or $30\text{ s}$ for $90^\circ$ Angle of Rotation Max $160^\circ$ Protection Class IP40 Ambient Temperature $-20\text{°C}$ to $+60\text{°C}$ Feedback Integrated high-precision potentiometer 3. Core FeaturesA. Integrated Potentiometer Unlike some SQN models where the potentiometer is optional, most STE models (especially the STE 50) feature a built-in, factory-calibrated potentiometer. This allows for continuous position feedback, which is essential for burners using electronic modulation rather than mechanical cams. B. High Resolution The STE series is known for its "step-free" or high-resolution movement. This makes it ideal for Low-NOx burners where the air damper must be positioned with sub-degree accuracy to maintain the correct flame chemistry. C. Connection Interface Many STE actuators do not use standard screw terminals. Instead, they often feature a pre-wired cable with a multi-pin plug (e.g., a 7-pin or 10-pin connector) designed to plug directly into the burner's main control board. 4. Maintenance and Troubleshooting The STE series is largely maintenance-free, but it is sensitive to mechanical stress: The "Hunting" Issue: If the internal potentiometer wears out or gets dirty, the actuator may "hunt" (move back and forth rapidly). This usually requires a replacement of the entire unit as the potentiometers are often integrated into the circuit board. Shaft Alignment: Most STE models use a specific "D-shaped" or splined shaft. When replacing, you must ensure the shaft is indexed correctly to the damper linkage before powering the unit. 5. Comparison: STE vs. SQN Size: STE is thinner and more "box-like," making it suitable for compact burner housings. Electronics: STE models usually contain more sophisticated onboard electronics for signal processing compared to the purely mechanical microswitches of the SQN series. Customization: STE units are often "OEM-specific," meaning a Siemens STE for an Elco burner might not be interchangeable with one for a Weishaupt burner due to the internal software or plug wiring.