A421ABC-04C Johnson Controls Temperature Control

Overview

The Johnson Controls A421ABC-04C is a single-stage line-voltage electronic temperature control designed for a wide variety of refrigeration or HVAC applications. It features a Type 1 NEMA IP20 high-impact plastic enclosure suitable for surface or DIN rail mounting, and includes an A99BB-400C PTC temperature sensor with a 2-inch standard probe and a 13.1-foot cable.

Features

• Bright backlit LCD screen with adjustable brightness and custom status icons.
• Simple three-button touchpad interface for navigating basic and advanced programming menus.
• Single-pole, double-throw SPDT output relay to switch heating or cooling equipment.
• Adjustable anti-short cycle delay to prevent compressor short cycling.
• Temperature setback and sensor offset capabilities.
• Optional restricted adjustment mode to lock setup parameters.

Specifications

• Supply Voltage: 120/240 VAC, 50/60 Hz
• Temperature Control Range: -40 to 212 degrees Fahrenheit (-40 to 100 degrees Celsius)
• Power Consumption: 1.8 VA maximum
• Enclosure Rating: NEMA 1, IP20 standard enclosure
• Output Relay Switch Action: SPDT

Applications

• On/off control of boilers and chillers.
• Heating and cooling control applications.
• Boiler and chiller pump control.
• Cooling tower fan control based on water temperature.
• Supply, makeup, and mixed air temperature control.
• Floating temperature control of damper and valve actuators.