Description
The Johnson Controls A421GEF-02 Electronic Temperature Control is a and simple product for maintaining temperature in harsh conditions in HVAC systems. A clear LCD screen is used to display the current temperature and the control setting. This is a long thin tube containing temperature sensitive liquid which is connected directly to the control unit but is positioned in a safe place away from the heat source with the other end used for temperature sensing. The control employs a (SPDT) relay output. When the capillary sensor records a temperature variation from the set temperature, the control switches on the relay to ensure that equipment such as heating or cooling components sustain the needed temperature.
