A421ABC-06C Johnson Controls Temperature Control

Overview

The Johnson Controls A421ABC-06C is a single-stage electronic temperature control designed to provide reliable on/off regulation for refrigeration, heating, and HVAC systems. It features a bright, adjustable backlit LCD screen and a simple three-button touchpad interface for simple setup and monitoring. Housed in a tough, high-impact plastic Type 1 (NEMA) IP20 enclosure, it is suitable for surface or DIN rail mounting. This model comes equipped with a remote A99 temperature sensor featuring a 2-inch probe and a 19.5-foot cable.

Features

• Easy-to-read, adjustable backlit LCD screen with custom status icons
• Three-button touchpad interface with an option for basic and advanced programming menus
• Restricted adjustment mode to prevent unauthorized parameter changes
• Adjustable anti-short cycle delay to protect compressors from short cycling
• Temperature setback and adjustable sensor offset capability
• LED status indicator showing the output relay’s On/Off state

Specifications

• Temperature Control Range: -40 to 212°F (-40 to 100°C)
• Ambient Operating Temperature: -40 to 150°F (-40 to 66°C)
• Supply Voltage: 120/240 VAC, 50/60 Hz
• Power Consumption: 1.8 VA maximum
• Output Relay: Single-Pole, Double-Throw (SPDT)
• Sensor Type: A99 PTC temperature sensor (1,035 ohm at 77°F) with 19.5-foot PVC cable and 2-inch probe
• Enclosure Rating: Type 1 (NEMA), IP20 high-impact thermoplastic

Applications

• On/off control of boilers, chillers, and chiller pumps
• Temperature monitoring and commercial refrigeration alarming (e.g., reach-in boxes, display cases, walk-in coolers)
• Heating and cooling control applications
• Condenser fan control based on water temperature
• Actuated valve and damper controls based on temperature signals