MEP-4251 | ACTUATOR; Tri-State / 2-Pos; 24VAC/VDC; Fail Safe; 25 in-lb

These compact but powerful direct-coupled ControlSet actuators provide two-position, tri-state, or proportional control for dampers or valves in HVAC systems. Efficient, durable, capacitor-driven fail-safe with switch-selectable direction provides consistent torque in both powered and fail-safe modes. A patented noise reducer provides whisper-quiet operation in both modes. A minimum torque of 45 (MEP-45xx) or 90 (MEP-49xx) in-lb. is available over the 95° angular rotation.

MEP-4xx2 proportional models accept either a 0–10 or 2–10 VDC control signal input from a thermostat, controller, or building automation system. “Anti-jitter” circuitry significantly reduces hunting and needless wear (from unnecessary miniscule position changes caused by undamped analog input signals) on the actuator, valve, or damper components. A user-initiated, auto-mapping feature provides more precise equipment control by reassigning the input signal range over a reduced rotation range. These models also feature a switch-selectable, 0–5 or 0–10 (or 1–5 or 2–10) VDC voltage feedback output that is proportional to the actuator position. (MEP-4252 shown in photo.)

MEP-4xx1 tri-state/two-position models are designed for use with floating thermostats, controllers, or building automation systems. MEP-4xx4/4xx5 two-position models are available in 24 VAC/VDC or 100-240 VAC models.

MEP-4x7x models also have one fully adjustable, built-in SPDT auxiliary switch for remote position indication or equipment interface. MEP-497x models include a second fixed switch at 10° from full CW direction. A three-foot cable is included with the switch(es).

MEP-4xxxV actuators have brackets with a patented, quick-mounting mechanism that mounts directly on VFB-43…BC and VFB-46…BC series valve bodies.

All actuators mount directly to 1/4- to 5/8-inch (6 to 16 mm) round shafts or 1/4- to 7/16-inch (6 to 11 mm) square shafts, eliminating the need for expensive and complicated linkages. A non-rotation bracket, to prevent lateral movement, is included with each actuator. A gear disengagement button allows easy manual positioning of the actuator.

(For similar actuators without fail-safe, see the MEP-4201/4501/4901 and the MEP-4000/4800 series. If higher torque is required, see the MEP-7500/7800 series.)