Schneider Electric (Barber Colman) MA-318 Actuator

The Schneider Electric (Barber Colman) MA-318 is a heavy-duty two-position oil-submerged actuator designed for the reliable operation of dampers, valves, and specialized HVAC linkages. Operating on a 24V AC power supply, this spring return actuator provides a robust 60 lb-in torque output, ensuring positive closure or opening upon power loss. For field technicians upgrading legacy systems, the MA-318 replaces ADHA-200, MA-308, and MA-315 models effectively. Note that proper installation requires the output shaft to be mounted horizontally to maintain the integrity of the internal oil bath. With a 70-watt running input and 25-watt holding capacity, this unit is engineered for long-cycle reliability in demanding commercial environments. Its die-cast aluminum housing protects the internal gear train, making it a staple for HVAC mechanical contractors looking for a direct-drive replacement actuator that integrates seamlessly with existing Barber Colman or Schneider Electric control loops.

Key Performance Benefits

• High Torque Output: Delivers consistent 60 lb-in torque for managing large damper assemblies and heavy-duty valve linkages.
• Fail-Safe Operation: Mechanical spring return functionality ensures the system returns to a safe state during power interruptions.
• Broad Compatibility: Serves as the primary replacement for MA-318-0-0-2, MA-318-0-0-3, and MC-151 series actuators.
• Durable Construction: Features an oil-submerged gear train for superior heat dissipation and reduced friction during high-duty cycles.
• Standardized Mounting: Utilizes a standard configuration for efficient field installation in existing control cabinets.

Common Technical Questions

What is the proper mounting orientation for the MA-318?
The unit must be installed with the output shaft in a horizontal position to prevent internal oil leakage and ensure proper lubrication of the gear components.

Can this actuator replace the older MA-305 or MA-308 units?
Yes, the MA-318 is the designated technical successor for the MA-308 and several ADHA series units, though you should verify linkage compatibility for specific valve bodies.

Is an external transformer required for this actuator?
The unit requires a 24V AC power source capable of handling the 70W peak running load and the 25W holding draw common in two-position control applications.

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Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.