MC-### 2 Position Actuator

Barber Colman / Invensys MC-Series 2‑Position Actuators

The MC-Series 2‑Position Actuators, including models like MC‑351, MC‑431, and MC‑421, are rugged, oil‑immersed, unidirectional actuators designed for two‑position control of dampers and valves in HVAC systems. They feature die‑cast aluminum housings, built‑in SPDT auxiliary switches, and compatibility with three‑wire control circuits (e.g., thermostats, pressure switches, relays)

Available in 24 VAC, 120 VAC, and 240 VAC versions, they deliver up to 220 lb‑in torque with ~30–70 second stroke timing.

Common Applications

Widely used in industrial and commercial HVAC environments, MC‑Series actuators control air dampers and globe valves for building ventilation, zoning, and process temperature control. Spring‑return variants (e.g., MA‑5213) ensure fail‑safe valve or damper closure during power loss. They’re ideal for large air-handling units, zone dampers, boiler control valves, and pressure relief systems.

Why Choose ControlRepair for Your MC‑Series Actuator:

• Repair options for common MC-series models (MC‑351, MC‑431, MC‑421, MC‑411)
• Full teardown, cleaning, gearbox/oil replacement, switch calibration, and reassembly
• Extensive testing to ensure reliable torque output and switch response
• Rapid turnaround and support—start your repair by visiting our repair page

Start your actuator repair or contact us to discuss model compatibility or troubleshoot installation issues.