A25CP-1C Johnson Controls Temperature Control

Overview

The Johnson Controls A25CP-1C is a mechanical warm air high-limit temperature control engineered to provide reliable overheat protection in forced-air systems. It features a bi-metal rod and tube sensing element that causes the control to lock out upon a temperature increase to the setpoint. A manual reset is required to reclose the electrical circuit once the temperature has dropped. This Factory Mutual (FM) approved model includes a concealed screwdriver slot range adjuster with a visible scale to prevent unauthorized tampering, making it ideal for commercial building automation and fire protection strategies.

Features

• Trip-Free Reset Lever: Prevents the system from being restarted or contacts from being blocked in a closed position until the lever is manually released.
• Concealed Adjuster: Features a concealed screwdriver slot range adjustment with a visible scale for secure, tamper-resistant operation.
• Heavy-Duty Sensing Element: The rod and tube sensing element provides positive control action, rapid response, and minimizes the risk of dirt build-up.
• Dust-Protected Switch: Enclosed SPDT switch includes an auxiliary contact to operate a warning light or audible alarm upon a high-limit trip.
• Dual-Voltage Pilot Duty: Certified for up to 600 VAC, allowing direct control of high-voltage motor starters.
• Adjustable Flange: Equipped with an adjustable duct mounting flange to accommodate varying insulation thicknesses and duct insertion depths.

Specifications

• Setpoint Range: 25 to 215°F (-4 to 102°C)
• Factory Stop Setting: High limit set at 125°F (52°C)
• Switch Type: SPDT (Single Pole Double Throw), opens on temperature rise (Red to Blue circuit opens; Red to Yellow circuit closes)
• Electrical Ratings: 16.0 Full Load Amps at 120 VAC; 9.2 Full Load Amps at 208 VAC; 8.0 Full Load Amps at 240 VAC; Pilot Duty rated at 125 VA (24 to 600 VAC)
• Enclosure Material: 0.063-inch galvanized steel case with a 0.025-inch cold-rolled steel cover
• Maximum Element Temperature: 300°F (149°C)
• Maximum Case Temperature: 104°F (40°C)
• Wiring Connections: Screw-type terminals
• Agency Listings: UL Recognized, CSA Certified, and Factory Mutual (FM) Approved (Class 3545)

Applications

• Return Air Ducts: Commonly installed in return air systems to automatically shut down air conditioning or ventilation fans in the event of excessive air temperature, such as during a building fire, conforming to NFPA No. 90A-1981 standards.
• Supply Air Ducts and Plenums: Used as a high-limit safety lockout control where required by local mechanical or building codes to prevent dangerous overheating.
• Equipment Safety Interlocks: Integrated into HVAC systems to shut down industrial burners, actuate ventilation dampers, or interface with high-voltage motor starters when air temperatures exceed acceptable operational parameters.