Johnson Controls a421gbf-02c Temperature Controller 24V

Product Description

The Johnson Controls a421gbf-02c is a single-stage electronic temperature controller designed for precise temperature management across a wide range of HVAC, refrigeration, and process control applications. Operating on 24 volts, it covers a sensing range of -10 to 212 degrees F, making it suitable for both low-temperature refrigeration and high-temperature process monitoring. The integrated display allows technicians to read setpoints and current sensor temperature at a glance without additional instruments. This controller is installed by licensed HVAC technicians and refrigeration mechanics working on commercial and light commercial systems.

The a421gbf-02c is well suited for commercial refrigeration cases, walk-in coolers, HVAC unit control, and process equipment where a dependable single-stage output with local display readout is required. Its 24-volt operating voltage fits naturally into low-voltage control circuits common in commercial refrigeration and HVAC systems. The wide sensing range makes it adaptable across cooling and heating applications without requiring separate controllers for different temperature zones.

Key Features

• Wide sensing range of -10 to 212 degrees F covers refrigeration and process heating applications
• 24-volt operating voltage integrates directly into standard low-voltage control circuits
• Integrated display provides local readout of setpoint and measured temperature
• Single-stage output simplifies wiring and control logic for straightforward on-off control
• Compact controller form factor suitable for panel or surface mounting in commercial equipment

Compatibility

Designed as an OEM-style single-stage temperature controller for use in commercial HVAC, refrigeration, and light process control applications requiring a 24-volt control circuit and a -10 to 212 degrees F sensing range.

Installation Notes

Installation should be performed by a qualified HVAC or refrigeration technician familiar with low-voltage control wiring practices. De-energize the control circuit completely before removing or connecting any wiring. Sensor placement is critical to accurate control — follow the equipment manufacturer's sensor location guidelines. Wiring should conform to NEC requirements for low-voltage Class 2 control circuits.

Technical Specifications

• Operating Voltage: 24 volts
• Temperature Sensing Range: -10 to 212 degrees F
• Display: Integrated

Standard Information

• Brand: Johnson Controls
• Manufacturer Part Number: a421gbf-02c