A421AET-01C Johnson Controls Temperature Control

Part number A421AET-01C from Johnson Controls, listed in Valves & Process Control. KKM Solutions quotes this part with pricing and availability confirmed per order.

Overview The Johnson Controls A421AET-01C is a single-stage electronic temperature control featuring a single-pole, double-throw (SPDT) output relay and an integrated cycle timer. Designed for precise temperature management, it includes a bright backlit LCD screen and an intuitive three-button touchpad interface. It comes equipped with a Type 4X (NEMA) / IP66 watertight, corrosion-resistant enclosure suitable for surface-mount installations, making it highly durable for challenging environments. Features High-visibility backlit LCD with adjustable brightness for convenient monitoring. Three-button touchpad interface for simple configuration and option restriction. Integrated On/Off duty-cycle timer for specialized ventilation or cooling controls. Adjustable anti-short cycle delay to protect compressors and HVAC equipment from rapid cycling. Temperature setback and sensor offset capabilities for tailored operation. LED indicator displaying the real-time On/Off status of the output relay. Keypad lockout functionality to prevent unauthorized adjustment changes. Specifications Temperature Control Range: -40 to 212°F (-40 to 100°C) Supply Voltage: Line-voltage model rated for 120/240 VAC, 50/60 Hz Relay Output: Single-pole, double-throw (SPDT) Power Consumption: 1.8 VA maximum Enclosure Rating: NEMA Type 4X / IP66 watertight, high-impact thermoplastic Included Sensor: A99BB-25C positive temperature coefficient (PTC) sensor with a 9-7/8 inch (0.25 m) PVC cable Applications On/off control of commercial boilers, chillers, and associated pump logic. Automated heating and cooling equipment regulations across diverse HVAC configurations. Floating temperature controls for dampening equipment and commercial valve actuators. Defrost cycle controls and cooling tower fan operations based on exact liquid temperatures. Industrial temperature monitoring, alerting, and general facility climate oversight.