A421AET-01C | Single Stage Temp Controller with Sensor, Duty-Cycle Timer, 24VAC, NEMA4X, 9" lead, -40 to 212F, HTG/CLG | JOHNSON

Description

The A421 Series controls are single-stage, electronic temperature controls with a singlepole, 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 with cycle timer can be powered with either 120 VAC or 240 VAC.

The A421 Control with Cycle Timer is a freecooling, duty-cycle ventilation control. This control provides timed-ventilation and overcooling protection.

A421 Control with Cycle Timer also provides sensor offset capability and restricted user adjustment. The temperature control 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.

Refer to the A421 Series Electronic Temperature Controls Product Bulletin (LIT-12012249) for important product application information.

The control housing base on the Type 4X/IP66 models can be easily rotated 180º relative to the control housing cover and LCD, allowing you to bring the electrical connection to either the top or bottom of the mounted control.

Applications

The A421 equipped with Cycle Timer is used in agricultural and related applications where free-cooling and ventilation are needed

Features and Benefits

•  Control Front Panel LCD – displays the temperature, parameters, and status and allows you to adjust the backlight brightness 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.
•  Free-Cooling and Ventilation – allows you to adjust for free-cooling and timed-ventilation, and provides over-cooling protection.
•  On/Off Temperature Adjustment – allows you to adjust the On/Off temperature values.
•  Switch-Activated Override – allows you to override the control using a switch connected to the binary input. Closing the switch turns the relay on. Normal control action is resumed when the switch is opened.
•  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 run the control continuously in the event of a sensor or sensor wire failure or to shut it down.
•  Backlight Brightness Level – allows you to adjust the brightness of the backlighting of the LCD screen. The backlight brightness level is applied during normal operation. When you set up or adjust the parameters, the LCD automatically goes to the brightest level.

Repair Information 

Do not attempt to repair or recalibrate the A421 Series Electronic Temperature Control. In case of a defective or improperly functioning control, contact your nearest Authorized Johnson Controls/PENN® Distributor or Sales Representative.

When contacting your Johnson Controls/ PENN distributor, have the model number of the control available. This number can be found on the label inside the cover of the control.

Ordering Information

Contact your nearest Johnson Controls/ PENN Distributor or Sales Representative to order sensors, mounting hardware, and other accessories used to install A421 controls. Contact your local Johnson Controls/PENN representative for more information on options available for high-volume purchase models with specific application requirements.