| Power Supply | 24 V AC/DC; 120 V AC; 230 V AC | Match the actuator voltage and frequency to the available control-panel supply. Do not connect a low-voltage actuator directly to a line-voltage circuit. | An incorrect supply can cause failure, overheating, electrical hazards, or loss of control. |
| Torque Requirement | Common actuator ranges: approximately 5–40 N·m for small to medium dampers; higher values for large or high-resistance dampers | Use the damper manufacturer’s required torque. Include friction, blade seals, duct pressure, linkage losses, and a reasonable safety margin. | Insufficient torque may prevent full closure or opening; excessive oversizing can increase cost and energy use. |
| Control Signal | Two-position; floating/three-point; proportional 0–10 V DC or 2–10 V DC | Select the signal type supported by the building-management system, controller, or thermostat. | Signal incompatibility can result in incorrect positioning, unstable operation, or no response. |
| Fail-Safe Function | Spring-return; electronic fail-safe; non-spring-return | Use spring return where the damper must move to a defined safe position after power loss. Specify the required fail position: open or closed. | Fail-safe behavior supports smoke control, freeze protection, ventilation, and equipment protection strategies. |
| Running Time | Approximately 30–150 seconds for a 90° rotation; faster models may be available for special applications | Choose a speed that meets the control sequence without causing excessive pressure changes, noise, or mechanical shock. | The wrong speed can reduce comfort, disturb airflow, or conflict with fire and smoke-control sequences. |
| Position Feedback | Auxiliary switch; 2–10 V DC feedback; potentiometric feedback; none | Specify feedback when the controller must verify damper position, provide interlocks, or report faults. | Feedback helps confirm operation and can prevent fans or heaters from running in an unsafe damper position. |
| Ingress Protection | IP20–IP30 for protected indoor areas; IP54 or higher for dusty or splash-prone locations, subject to installation conditions | Choose an enclosure rating appropriate to dust, water, condensation, and cleaning methods. An IP rating does not automatically mean suitability for immersion or corrosive chemicals. | Adequate protection reduces the risk of corrosion, short circuits, and premature actuator failure. |
| Operating Temperature | Typical HVAC ranges are about −30°C to +50°C; the exact range depends on the actuator design | Check both ambient temperature and the temperature conducted through the damper shaft. Allow for startup conditions and seasonal extremes. | Operating outside the rated range may reduce torque, damage electronics, or shorten service life. |
| Humidity and Condensation | Non-condensing indoor use; protected outdoor use; high-humidity applications with suitable enclosure protection | For humid or changing environments, verify the product’s condensation limits and provide drainage, shielding, or a suitable enclosure where required. | Condensation can cause corrosion, insulation breakdown, and intermittent control faults. |
| Corrosion Exposure | Standard indoor atmosphere; coastal or industrial atmosphere; chemically aggressive environment | Confirm material compatibility for salt spray, cleaning agents, chlorine, acids, solvents, and other chemicals. Use protected materials or a remote mounting arrangement when necessary. | Corrosion can seize the shaft, weaken mounting hardware, and compromise enclosure integrity. |
| Electrical Safety | Class III SELV for many 24 V systems; Class II double-insulated designs; protective earthing for applicable line-voltage equipment | Verify the actuator’s insulation, grounding, terminal protection, and installation requirements against local electrical codes. | Correct protection limits electric-shock and fire risks and supports code-compliant installation. |
| Fire and Smoke Application | Standard HVAC actuator; smoke-control actuator; fire-rated damper assembly | For life-safety systems, select an actuator that is specifically tested and listed with the damper assembly for the intended fire or smoke-control duty. | A general HVAC actuator must not be assumed suitable for fire or smoke control. |
| Noise and Mounting | Low-noise indoor operation; standard mechanical room installation; vibration-resistant mounting | Consider motor noise, damper linkage alignment, shaft size, rotation angle, mounting orientation, and available clearance. | Correct installation prevents vibration, binding, noise, and premature wear. |
| Energy Consumption | Low-power modulating designs; higher short-term power during movement; spring-return models with additional spring-charging demand | Compare running power, standby power, duty cycle, and spring-return consumption rather than looking only at nominal voltage. | Lower operating energy can reduce panel loading and lifecycle operating costs. |