Barber Colman (Schneider Electric) MC-421 Damper Actuator
The Barber Colman MC-421, now offered under Schneider Electric, is an electric damper actuator designed for two-position control in HVAC systems. Engineered for applications requiring reliable damper or valve operation without a return to a default position upon power loss, the MC-421 provides consistent performance in heating, ventilation, and air conditioning setups.
Technical Specifications
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Model: MC-421
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Type: Electric Damper Actuator
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Control Circuit: Three-wire system utilizing a Single-Pole, Double-Throw (SPDT) snap-acting switch or equivalent device
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Shaft Rotation: Unidirectional clockwise rotation up to 180° when powered
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Power Supply: Available in 24, 120, and 240 Vac models
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Power Consumption: 50 watts; 96 VA rating
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Torque Output: Rated at 175 lb-in (20 N-m)
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Nominal Damper Area: Suitable for parallel blade dampers up to 97 sq. ft. (9 m²) and opposed blade dampers up to 125 sq. ft. (12 m²)
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Auxiliary Switch: Adjustable SPDT switch, factory-set to actuate at mid-stroke; one contact closes at the end of the stroke, the other at the end of the next stroke
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Ambient Temperature Limits: Operating range from -40 to 136°F (-40 to 58°C)
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Humidity Range: 5 to 95% relative humidity, non-condensing
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Housing: Rugged die-cast aluminum with two 1/2-inch conduit openings; optional NEMA 4 rating with AM-363 gasket
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Gear Train: Oil-immersed for enhanced durability
Key Features
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Reliable Two-Position Control: Provides consistent on/off control for dampers or valves in HVAC systems.
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Unidirectional Operation: Clockwise rotation ensures predictable actuator movement.
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Integrated Auxiliary Switch: Facilitates additional control functions or feedback mechanisms.
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Durable Construction: Die-cast aluminum housing and oil-immersed gear train enhance longevity and performance.
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Versatile Mounting Options: Compatible with various mounting brackets and linkage kits for flexible installation.
Compatible Components & Accessories
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Crank Arms: AM-113 (for actuator or 1/2-inch diameter damper shaft)
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Linkage Connectors: AM-122 (straight type), AM-132 (ball joint connector)
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Damper Rods: AM-125 (5/16-inch diameter x 20 inches), AM-125-048 (5/16-inch diameter x 48 inches)
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Mounting Brackets: AM-301 (90-degree mounting bracket)
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Auxiliary Switch Kits: AM-321 (two-step switch kit), AM-341 (four-step switch kit)
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Gasket Kit: AM-363 for NEMA 4 rated applications
Industry Applications
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HVAC Systems: Ideal for controlling dampers in heating, ventilation, and air conditioning systems.
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Building Automation: Integrates with automated control systems for efficient building management.
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Industrial Ventilation: Suitable for managing airflow in industrial environments requiring robust actuator performance.
Installation & Maintenance Notes
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Wiring: Ensure compliance with national and local electrical codes; use appropriate wire gauges based on run length and voltage.
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Mounting: Preferred orientation is upright, allowing six inches of clearance above the actuator wiring compartment; other positions are acceptable except upside down or with the output shaft pointing upward for adjustable speed units.
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Adjustment: The auxiliary switch operating point can be modified by inserting a screwdriver through the top plate opening and turning the gear-like plastic disc; each click represents approximately a 3-degree change in operating point.
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Inspection: Regularly check for signs of wear, oil leaks, or electrical issues; maintain oil levels using TAC immersion oil as specified.
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Safety Precautions: Disconnect power before installation or maintenance; never attempt to turn the actuator shaft manually with a wrench or crank to avoid gear damage.
The Barber Colman MC-421 electric damper actuator offers dependable two-position control for various HVAC applications, ensuring precise airflow regulation and contributing to overall system efficiency.
We ship this product worldwide! Delivery is normally stock.
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