Love may be complicated, but control is simple and clear with Johnson Controls/PENN

Presenting the easy-to-use A421 Series Electronic Temperature Controls with advanced control for more application versatility.

Save installation time and costs with faster programming using a simple 3-button touchpad interface with backlit display. The A421 Series are single-stage controls with a single-pole, double-throw (SPDT) output relay. Integrated off-cycle defrost and interval timer models are available.

Can be used to control a wide variety of single-stage refrigeration or HVAC equipment. Includes:

• Temperature monitoring and alarming
• On/off control of boilers and chillers
• Boiler and chiller pump control
• Heating and cooling control
• Floating temperature control of damper and valve actuators
• 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 and temperature


• Easy-to-read, bright, adjustable backlit LCD screen displays temperature, parameters and status clearly and allows you to adjust LCD brightness for the ambient light conditions.
• Basic and advanced programming menus-allow you to easily set up your control application on the LCD using a simple three-button touchpad interface.
• Adjustable On and Off temperature setpoints-enable easy to set up cooling or heating control applications on the three-button touchpad, eliminating the need to remove the cover and reposition jumpers for reverse or direct control actions.
• High and low temperature setpoint adjustment stops-allow you to set up your application for your desired range of adjustment and restrict user adjustment to just the desired temperature adjustment range.
• Displayed temperature offset-allows you to adjust the displayed temperature to the actual sensed temperature in applications where the resistance error in long sensor cable leads cause a deviation in the displayed temperature from the actual sensed temperature.
• Adjustable anti-short cycle delay-keeps the output relay Off after the Off setpoint is reached.

For more info, stop by your ABCO Branch today.