The Advantages of Acquiring a Fail Safe Electric Actuator
Actuators are utilized to automate industrial valves, which are then used in various kinds of technical process facilities. Some of the industrial facilities where actuators are typically used include water treatment, power generation and refineries. Like valves, actuators can also vary in dimension and style. A fail safe electric actuator is a special actuator classification, which primarily draws energy from an electrical power source in order to function.
A loss of power for an electric actuator can cause severe damage not only to the valve it controls but also to entire process system. Thus, a fail safe electric actuator typically is equipped with a fail safe control panel and a battery backup power supply which contains a specific electric power capacity. In the event of power loss, the electric actuator’s relay system, which monitors line voltage, will automatically detect the power interruption. This then prompts the relay to signal the actuator to assume fail safe position. When this happens, the backup power supply feeds electrical energy to the spring mechanism which controls the actuator. This automatic switch of power supply enables the actuator to still function in the event of utility power loss. When the utility power is regained, the fail safe electric actuator then reverts to getting power from an external electrical source.
The fail safe device for electric actuators is sold in different models. In selecting the right fail-safe device, one should consider important factors. The first factor involves matching the power delivered by the fail safe device to the power needed by the actuator. For example, a fail-safe device that offers 115V/1Ph/60Hz power can be used with any 115V/1Ph/60Hz electric actuator, as long as the sizing is right. The second factor to consider involves making sure that the lock rotor current of the electric actuator suits the output current of the fail safe device.
Many industrial applications, especially in the ship-building industry, prefer to use fail safe electric actuator primarily for safety reasons. However, fail safe electric actuators also offer other advantages compared to a pneumatic or hydraulic actuators. Fail safe electric actuator units are more compact and easier to install. In addition, it is more economical to transport electric energy compared than compressed air or oil. Pneumatic and hydraulic actuators have pipelines that require more maintenance than electrical wiring. For electric actuators, energy is only required if a movement occurs, but actuators that are pneumatic and hydraulic must have a working pressure that must remained constant all throughout the operation. Although hydraulic systems can shut down automatically in power failure situations, they are more costly, complex and require more space.
Most of the latest fail safe electric actuator models are powered by the lithium battery technology. Some even have a dependable clutching mechanism when spring failure occurs during loss of power. Actuators with fail safe electric device also come with a special screen where battery power level is indicated. Manufacturers purposely make the actuator batteries small so that they can fit with the other actuator components in one housing. The size of batteries also makes it easier to replace them after a certain period of time.