A11D-4C Johnson Controls RESet

Overview

The Johnson Controls A11D-4C is a compact and sturdy low-temperature cutout control designed for environmental monitoring in HVAC applications and building automation systems. It senses low-temperature conditions to prevent overcooling or icing of hydronic coils, cooling coils, and liquid-handling pipes. This model features single-pole, double-throw (SPDT) contact action and a trip-free manual reset mechanism that requires manual intervention before operation resumes.

Features

• Trip-free manual reset mechanism that activates only after the temperature rises 12°F (6.7°C) above the setpoint
• Precision snap-acting contacts housed in a dust-protected enclosure for optimal reliability
• Vapor-charged sensing element that reacts to the coldest section of the bulb
• Direct reading scale providing an easy-to-adjust setpoint from either the top or bottom of the control
• Precision repeat accuracy that remains unaffected by ambient temperature at the control diaphragm cup

Specifications

• Setpoint Range: 35°F to 45°F (2°C to 7°C)
• Switch Action: SPDT
• Differential: 12°F (6.7°C) fixed manual reset
• Capillary Length: 4 feet (1.2 m)
• Maximum Bulb Temperature: 250°F (121°C)
• Electrical Rating: 16A at 120 VAC, 9.2A at 208 VAC, 8A at 240 VAC; 1 HP

Applications

• Monitoring the trailing face of an HVAC coil for freeze protection
• Sensing low-temperature conditions in hydronic heating and cooling coils
• Protecting liquid-handling pipes from freezing or icing
• Integrating into commercial building automation systems for low-limit temperature cutout functions