The Vahn-Tech Series VT-S Spring-Return Fail-Safe Electric Actuators in addition to the normal function (floating control, on-off control, modulating control) are designed to provide fail-safe positioning of valves and dampers upon loss of power supply. A mechanical spring set is used to position the controlled device to either the fully OPEN or fully CLOSED position without any external power source. For ON-OFF type, a mechanical buffer is employed at the end of the spring stroke in order to reduce the dynamic effects of the spring return system. A clutch-free manual override is available as an option for standard units to provide full-time manual positioning of the valve.
Additional information
| Type | Non-Intrusive |
|---|---|
| Operation | Quarter-Turn |
| Design | Spring-Return Electric |
| Sizes | 500, 1300, 2000, 2600 |
| Maximum Output | 260 Nm (2,302 in-lbf) |
| Power Supply | DC: 24V; 1-Phase: 24V, 110V, 220V; 3-Phase: 380V, 440V |
| Operation Modes | On/Off, Modulating |
| Control Signals | Discrete, Floating, Analog |
| Motor Rating | F, H |
| Duty Cycle | 0.5 |
| Feedback | 2x SPDT Limit Switches, Extra Limit Switches, Potentiometer, Analog Output |
| Ingress Rating | IP 67 (NEMA 4X) |
| Fail Safe Operation | Open, Closed |
| Enclosure | Dry Polyester Powder Coated Aluminum |
| Position Indicator | Rotary Dome |
| Temperature Range | -30°C to 70°C (-22°F to 158°F) |
| Manual Override | None, Non-Clutchable Handwheel |
| Options | Space Heater, Heater Thermostat |
Features & Benefits
- Built-in thermal protection prevents motor burnout
- Self-locking function provides a stable, reliable and powerful drive system
- Gear trains have been already lubricated sufficiently with high temperature resistant lubricant at the factory
- All models have continuous mechanism position indicator on the top actuator cover
- The actuator complies with NEMA 4X (IP 67) standard, water proof and dust-proof enclosure
- Manual override with handwheel in option
- ATEX and CSA Certified for hazardous and explosion proof area
