Johnson Controls

Johnson Controls - A421ABC-02C - Digital Electronic Temperature Control, NEMA1, 120VAC

Item: JOHA421ABC02C
MFG: A421ABC-02C
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A421 Series Electronic Temperature Controls with Cycle Timer

The A421 Series controls are single stage, electronic temperature controls with a single-pole, double-throw (SPDT) output relay. The controls feature an adjustable backlit LCD for viewing the temperature and status of other functions, and a three-button touchpad for setup and adjustment. An LED indicates the On/Off status of the output relay.

The A421 controls are available in low voltage 24 VAC and high voltage 120 or 240 VAC models, which provide options for most refrigeration and HVAC applications.

The A421 controls provide heating or cooling control, sensor offset, temperature setback, adjustable anti-short cycle delay, and a restricted user adjustment mode. The temperature units can be displayed in °F or °C. The temperature adjustment range is -40 to 212°F or -40 to 100°C.

The A421 controls are available in Type 1/IP20 high-impact plastic enclosures suitable for surface or DIN rail mounting and Type 4X/IP66 watertight, corrosion-resistant surface mount enclosures.

Some A421 Series control models are equipped with factory-installed power cords. The power cords provide convenient plug-in connection and control of 120 VAC heating and cooling equipment.

The A421 Electronic Temperature Control can be used to control a wide variety of single-stage refrigeration or HVAC equipment.
Sample temperature control applications include:
  • temperature monitoring and alarming
  • on/off control of boilers and chillers
  • boiler and chiller pump control
  • heating or cooling control
  • cooling tower fan control based on water temperature
  • supply, makeup, and mixed air temperature control
  • temperature actuated valve control
  • supply and makeup air damper and fan control
  • condenser fan control based on condenser temperature.

California residents: see Proposition 65 Warning

Features and Specification

Weight 1.000000
Prop 65 Yes
Stage Two
Package Weight 1.100000
Phase Single
Package Height 4.500000
Package Length 6.500000
Package Width 5.000000
Width 4.000000
Voltage 120/240 VAC
Length 5.500000
Cubic Measurement 0.044600
Brand Johnson Controls
Cycle/Hertz 50/60 Hz
Height 3.500000
Dimensional Weight 2.000000