1. Introduction
This manual provides essential information for the safe and efficient installation, operation, and maintenance of the BELIMO LF24-S US Spring Return Actuator. Please read this manual thoroughly before attempting any installation or operation.
The BELIMO LF24-S US is a high-quality spring return actuator designed for precise control in various industrial applications. It operates on 24V AC/DC and features a robust design for reliable performance.
2. Safety Information
WARNING: Electrical shock hazard. Disconnect power before installation or servicing. Installation and maintenance should only be performed by qualified personnel.
- Ensure all local and national electrical codes are followed.
- Verify the power supply voltage matches the actuator's specifications (24VAC/DC).
- Do not operate the actuator beyond its specified torque or operating limits.
- Protect the actuator from moisture and extreme temperatures unless specifically rated for such conditions.
3. Product Overview
The BELIMO LF24-S US is a compact spring return actuator. Key features include:
- Model: LF24-S US
- Power Supply: 24VAC/DC, 50/60Hz, 7VA, 5W
- Torque: 35 in-lb (4Nm)
- Operating Time: Approximately 75 seconds (motor), 20 seconds (spring return)
- Certifications: NEMA 2, Class 2 Supply, CE, UL US Listed
- Auxiliary Switch: 3A at 250VAC (S1, S2, S3 terminals)
Figure 1: BELIMO LF24-S US Spring Return Actuator. This image shows the front view of the actuator, highlighting the model number, brand, power specifications, torque rating, operating times, certifications, and wiring terminals. A mounting bracket is visible at the top.
4. Specifications
| Feature | Specification |
|---|---|
| Model Number | LF24-S US |
| Power Supply | 24VAC/DC, 50/60Hz |
| Power Consumption | 7VA (apparent), 5W (rated) |
| Torque | 35 in-lb (4Nm) |
| Motor Run Time | 75 seconds |
| Spring Return Time | 20 seconds |
| Auxiliary Switch Rating | 3A at 250VAC |
| Certifications | NEMA 2, Class 2 Supply, CE, UL US Listed |
| Product Dimensions | 9 x 3 x 4 inches |
| Weight | 3.44 Pounds |
| Mounting Type | Wall Mount |
| Connector Type | Screw |
| Material | Plastic |
| Color | Orange |
5. Setup and Installation
5.1 Mounting
- Ensure the mounting surface is stable and capable of supporting the actuator's weight (3.44 lbs).
- Mount the actuator using appropriate fasteners for wall mounting. The actuator includes a mounting bracket as shown in Figure 1.
- Ensure sufficient clearance for wiring and maintenance access.
5.2 Wiring
Refer to the wiring diagram provided with the actuator for specific connections. General wiring guidelines are as follows:
- Connect the 24VAC/DC power supply to the designated power terminals (e.g., '1' and '2' or 'COM' and '+').
- Utilize the screw-type connectors for secure electrical connections.
- If using auxiliary switches, connect external circuits to terminals S1, S2, S3 as required. These switches are rated for 3A at 250VAC.
- Ensure all wiring complies with NEMA 2 and Class 2 Supply standards.
6. Operating Instructions
The BELIMO LF24-S US actuator is designed for automatic operation based on control signals. It features a spring return mechanism.
- Upon receiving a control signal, the actuator will drive the connected damper or valve to its commanded position. The motor run time is approximately 75 seconds.
- In the event of power loss or removal of the control signal, the spring return mechanism will automatically drive the actuator to its default (fail-safe) position within approximately 20 seconds.
- The position indicator on the actuator (marked 0-6 and CW) shows the current rotational position. "CW" indicates clockwise rotation.
7. Maintenance
The BELIMO LF24-S US actuator is designed for maintenance-free operation under normal conditions. However, periodic checks are recommended:
- Visual Inspection: Periodically inspect the actuator for any signs of physical damage, loose connections, or corrosion.
- Wiring Integrity: Ensure all electrical connections remain tight and secure.
- Functionality Test: Verify the actuator operates smoothly through its full range of motion and that the spring return function is operational.
Do not attempt to lubricate or disassemble the actuator, as this may void the warranty and compromise its performance.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Actuator does not move | No power supply; Incorrect wiring; Faulty control signal | Check power connections and voltage; Verify wiring against diagram; Test control signal source. |
| Actuator moves slowly or erratically | Insufficient power; Mechanical obstruction; Damaged unit | Confirm stable 24VAC/DC supply; Inspect for obstructions in the connected mechanism; If damaged, contact support. |
| Spring return not functioning | Internal spring mechanism failure; Mechanical obstruction | Ensure no mechanical obstruction; If issue persists, the unit may require replacement. |
For problems not listed or if solutions do not resolve the issue, contact technical support.
9. Warranty and Support
9.1 Warranty
The BELIMO LF24-S US Spring Return Actuator is covered by the manufacturer's standard warranty. For detailed warranty terms and conditions, please refer to the official documentation provided by BELIMO or contact your supplier. Unauthorized repairs or modifications may void the warranty.
9.2 Technical Support
For technical assistance, troubleshooting guidance, or spare parts inquiries, please contact your authorized BELIMO distributor or the BELIMO customer support team. Have your model number (LF24-S US) and serial number (if applicable) ready when contacting support.
