A-4417-1 Johnson Controls Air Dryer

Overview

The Johnson Controls A28MA-1C is a heavy-duty, electromechanical two-stage temperature control device designed for general-purpose HVAC/R applications. Housed in a rainproof, splash-resistant NEMA 3R enclosure, it utilizes a liquid-filled copper remote sensing bulb and capillary element that provides uniform control unaffected by barometric pressure or cross-ambient temperature variances. It offers dependable two-stage control by utilizing two independent single-pole, double-throw (SPDT) snap-acting switches.

Features

• Two-Stage Control: Features two enclosed SPDT switches permitting independent control circuits for flexible heating, cooling, or staging configurations.
• Durable Enclosure: Equipped with a rugged steel rainproof NEMA 3R splash-resistant enclosure suitable for outdoor or harsh environments.
• Reliable Sensing Element: Liquid-filled copper remote bulb and capillary ensure accurate temperature tracking and long-term performance stability.
• Adjustability: External screwdriver slot adjustment allows for easy adjustments to the setpoint dial.

Specifications

• Temperature Range: 40°F to 120°F (4°C to 49°C)
• Switch Action: Dual SPDT snap-acting switches
• Differential: Factory set at 5°F (2.8°C) for each stage; 8°F (4.4°C) between stages
• Capillary Length: 6 feet (1.8 meters)
• Bulb Dimensions: 3/8 inch diameter x 4 inches length (9.5 mm x 101.6 mm)
• Electrical Ratings: 1 HP motor rating; compatible with 120 VAC, 208 VAC, and 240 VAC line voltages
• Enclosure Type: NEMA 3R (Splash-resistant / Rainproof)

Applications

• Cooling tower sump water temperature control
• Evaporative condenser monitoring and staging
• Fan cycling control for air-cooled condensers
• Commercial refrigeration and environmental temperature regulation systems