The A421 Series Standard Electronic Temperature Controls are single-stage electronic temperature controls with a single-pole, double-throw (SPDT) output relay. The controls feature an adjustable backlit LCD to view the temperature and status of other functions, and a three-button touchpad for setup and adjustment. An LED indicates the On or Off status of the output relay. You can power the A421 control models that contain a cycle timer, with either 120 VAC or 240 VAC.
The A421 control with a cycle timer is a free-cooling, duty-cycle ventilation control. The control provides timed-ventilation and over-cooling protection.
The A421 control with a cycle timer also provides sensor offset capability and restricted user adjustment. The temperature control range is -40°F to 212°F or -40°C to 100°C.
The A421 controls are available in Type 1/IP20 high-impact plastic enclosures that are suitable for surface or DIN rail mounting, and Type 4X/IP66 watertight, corrosion-resistant, surface-mount enclosures.
You can rotate the control housing base on the Type 4X/IP66 models 180º relative to the control housing cover and LCD, to bring the electrical connection to either the top or bottom of the mounted control.