For On/Off, fail-safe control of dampers in HVAC systems. Actuator sizing should be done in accordance with the damper manufacturerâ€™s specifications. Control is On/Off from an auxiliary contact, or a manual switch.
The actuator is mounted directly to a damper shaft up to 1.05â€ in diameter by means of its universal clamp. A crank arm and several mounting brackets are available for applications where the actuator cannot be direct coupled to the damper shaft.
The EFB and EFX series actuators provide true spring return operation for reliable failsafe application and positive close off on air tight dampers. The spring return system provides constant torque to the damper with, and without, power applied to the actuator.
The EFB and EFX series provides 95Â° of rotation and is provided with a graduated position indicator showing 0Â° to 95Â°.
The actuator may be stalled anywhere in its normal rotation without the need of mechanical end switches.
The EFB120-S and EFX120-S versions are provided with two built-in auxiliary switches. These SPDT switches provide safety interfacing or signaling, for example, for fan start-up. The switching function at the fail-safe position is fixed at +10Â°, the other switch function is adjustable between +10Â° to +85Â°. The EFB120, EFB120-S, EFX120 and EFX120-S actuator is shipped at +5Â° (5Â° from full fail-safe) to provide automatic compression against damper gaskets for tight shut-off.
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