Schneider Electric (Barber Colman) MA-318-500 Actuator

The Schneider Electric (Barber Colman) MA-318-500 is an industrial-grade two-position actuator engineered for heavy-duty spring return operation in damper and valve assemblies. Operating on 24V AC, this rotary oil-immersed motor provides a reliable 60 lb-in torque output, ensuring positive closure or opening upon power interruption. The internal gear train and motor are housed in a rugged die-cast aluminum NEMA 4 enclosure, designed for longevity in demanding mechanical environments. This specific model features a built-in SPDT auxiliary switch to facilitate end-of-travel position signaling or interlocking with secondary equipment. A critical installation requirement for the MA-318-500 is that the output shaft must remain in a horizontal orientation to maintain proper lubrication and internal operational integrity. With a power consumption profile of 70 watts during the running phase and 25 watts for holding, it serves as the direct field replacement for legacy ADHA-200A and older MA-318-500-0-x series units.

Key Benefits:

• Compatible with standard two-wire SPST control circuits for simplified HVAC actuator wiring.
• Robust 60 lb-in torque rating suitable for medium-sized dampers and globe valve linkages.
• Integrated auxiliary switch (SPDT) for precise end-of-stroke feedback and system sequencing.
• Durable NEMA Type 4 aluminum housing provides protection against windblown dust and moisture.
• High-reliability spring return actuator mechanism ensures safety-positioning during power loss.

Common Questions:

Can the MA-318-500 be mounted vertically?
No, this unit is designed specifically for horizontal shaft mounting. Installing it with the shaft in a vertical position can lead to oil migration and premature motor failure.

Is this actuator compatible with modulating 0-10V signals?
No, the MA-318-500 is a strictly two-position (on/off) actuator. It is not designed for proportional or modulating control applications.

What is the typical stroke timing for this unit?
The power stroke timing varies by load, but the spring return stroke typically completes in approximately 60 seconds under full load conditions.

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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.