A70KA-1C Johnson Controls Temperature Control

Overview

The Johnson Controls A70KA-1C is a heavy-duty, mechanical remote bulb temperature control engineered for demanding HVAC, refrigeration, and industrial applications. It features a vapor-charged sensing element and a four-wire, two-circuit contact block containing two isolated sets of contacts designed to transfer at the setpoint. When the main contact opens on temperature rise, the auxiliary contact closes simultaneously. This model includes a manual reset function for added safety, ensuring manual intervention is required after a high-temperature trip.

Features

• Heavy-duty four-wire, two-circuit contact configuration
• Manual reset mechanism for critical high-limit safety monitoring
• Snap-acting isolated contacts (Main opens high, Auxiliary closes low/high)
• Vapor-charged remote sensing bulb and capillary assembly
• Rugged construction suitable for commercial and industrial environments

Specifications

• Setpoint Temperature Range: 100°F to 170°F (38°C to 77°C)
• Differential: 8°F (4.4°C) Fixed
• Switch Action: 1 NO / 1 NC (Main Open High)
• Bulb Size: 3/8 inch diameter x 10 inches length
• Capillary Length: 6 feet
• Maximum Bulb Temperature: 240°F (116°C)
• AC Voltage Rating: 120 V / 240 V

Applications

• High-limit safety control in industrial heating systems and boilers
• Ventilation system shutdown and building automation system (BAS) alarm indication
• Critical process temperature management where automatic restarts must be prevented
• Commercial HVAC and industrial refrigeration systems