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Johnson Controls

Watertight Electronic Temperature Control with Single Power Cord and Piggyback Plug

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Johnson Controls' A421AEJ-02C Type 4X Electronic Temperature Control with Piggyback Plug lets you convert any freezer into a kegerator or fermentation chamber by overriding the appliance's thermostat, giving you precise control over the temperature settings. The 4X is made from corrosion-resistant high-impact thermoplastic that is watertight, making it ideal for areas that may need to be washed or watered down. The device comes factory wired with a 6 ft. (1.8 m) cord with 120 VAC grounded piggyback plug with both a male plug and a female outlet. To use, simply plug your appliance into the female outlet and plug the male plug into an electrical outlet. The intuitive three-button touchpad allows for easy setup and adjustment, while the adjustable backlit LCD display lets you view the temperature, parameters and the status of other functions. You can view the temperature in either Fahrenheit or Celsius, and adjust the temperature between -40 to 212 degrees Fahrenheit or -40 to 100 degrees Celsius. An LED light lets you quickly check the On/Off status.

To give you even more control over your appliance's cooling and heating, the A421AEJ-02C was designed with convenient features like sensor offset to let you adjust the displayed temperature to the actual sensed temperature and switch-activated temperature setback to allow you to shift the on/off temperature by an adjustable setback value. It also comes equipped with adjustable anti-short cycle delay to allow you to select the minimum time that the output relay remains on before the next on cycle, and an optional restricted user adjustment mode to let you restrict the on/off adjustment to your defined temperature range.

The A421AEJ-02C is suitable for many refrigeration and HVAC applications, including agricultural, beverage, food service, ice machine, process, refrigeration, space heating, and ventilation applications. It has a durable Type 4 (NEMA)/IP66 watertight corrosion-resistant enclosure for surface mount applications, and features an A99BB-200C temperature sensor with a standard 2 in. (5.1 cm) probe and a 6.6 (2.0 m) PVC cable.

  • Control Front Panel LCD:
    Displays the temperature, parameters, and status and allows you to adjust the backlight intensity for ambient light conditions. Custom icons display the system and control status.
  • Basic and Advanced Programming Menu:
    Provides two levels of parameter adjustment and control setup, allowing you to set up advanced features in one menu and easily adjust basic parameters in the other menu.
  • On/Off Temperature Adjustment:
    Allows you to select the temperature values at which the relay turns On or Off, which automatically defines the Heating or Cooling mode of operation.
  • Switch-Activated Temperature Setback:
    Allows you to shift the On/Off temperature by an adjustable setback value. When a user-supplied switch closes the binary input control circuit, the control operates at a defined setback temperatures.
  • Adjustable Anti-Short Cycle Delay:
    Allows you to select the minimum time the output relay remains off before the next on cycle; avoiding short cycling, hard starts, and nuisance overload outages on compressors and other inductive applications.
  • Adjustable Sensor Offset:
    Allows you to adjust the displayed temperature to the actual sensed temperature.
  • Optional Restricted Adjustment Mode:
    Allows you to restrict the On/Off adjustment to your defined temperature range.
  • Sensor Failure Mode:
    Allows you to select the relay On/Off state in the event of a sensor or sensor wire failure.
  • Backlight Brightness Level:
    Allows you to adjust the LCD backlight intensity.
PDFInstallation Instructions

Watertight Electronic Temperature Control with Single Power Cord and Piggyback Plug Reviews

Average Customer Rating:
(based on 2 reviews) 
works good so far
by:Ron (08-01-2017)
State of Jefferson
Comments:I bought this temperature control for a chest freezer to replace the original temperature control that had quit working and was no longer available. It is very easy to hook up and set. I do not use any of the advanced controls so they may be a little more difficult to set.
Bottom Line:I would recommend this product.
Designed by engineers for engineers
by:Phil the pilot (05-23-2017)
Durham, PA
Comments:Using to keep wine at cellar temp in dedicated fridge.
Works perfectly....once you figure out how to get it set up, and you'd think that with only three buttons it couldn't possibly be that hard. Ever wonder what happened to the guys who designed the impossible-to-program clocks on VCR's? They now make these. Had to watch youtube videos to set up, but I'm just a liberal arts major who is at least handy enough to fly a Boeing for a living.
Bottom Line:I would recommend this product.

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