A421GBF-02C Johnson Controls Temperature Control

Overview

The Johnson Controls A421GBF-02C is a low-voltage, single-stage electronic temperature control with a single-pole, double-throw (SPDT) output relay. It features a bright backlit LCD screen and a three-button touchpad interface, providing reliable heating or cooling control for HVAC and refrigeration systems. The control is housed in a Type 1 (NEMA) IP20 high-impact plastic enclosure designed for surface or DIN rail mounting.

Features

• Easy-to-read, adjustable backlit LCD screen with visual status icons
• Simple three-button touchpad interface for basic and advanced programming
• Adjustable On and Off temperature setpoints for heating or cooling control
• High and low temperature setpoint stops to restrict unauthorized user adjustments
• Adjustable anti-short cycle delay to protect compressors from short cycling
• Temperature setback capability via external switch input for energy savings
• Displayed temperature offset to correct resistance errors in long sensor leads
• LED indicator providing clear visual confirmation of the output relay status

Specifications

• Supply Voltage: 24 VAC, Class 2, Safety Extra-Low Voltage
• Power Consumption: Maximum 1.8 VA
• Temperature Control Range: -40 to 212 degrees Fahrenheit (-40 to 100 degrees Celsius)
• Switch Configuration: SPDT dry-contact relay
• Enclosure Rating: Type 1 (NEMA), IP20 high-impact thermoplastic
• Sensor Type: Includes an A99BB-200C positive temperature coefficient (PTC) temperature sensor with a 6.6-foot (2.0-meter) cable

Applications

• Commercial refrigeration equipment temperature control
• HVAC heating and cooling system monitoring and control
• Compressor protection and inductive application control
• Occupied/unoccupied temperature setback scheduling in commercial environments
• Food service equipment and general-purpose temperature regulation