Post-heater for HVAC installation

For the storage of basic and end products within the "Life Science" industry, more and more high demands are made with regard to storage temperature as well as humidity.
The setup of this project consists of a powerful cooling module that cools the process air in order to reduce the moisture to a desired minimum% RH.

In series with the cooling group, the post-heater is placed in the air stream to also heat up the resulting dry air again to the desired temperature.
For this we use a control circuit consisting of a resistive group of heating elements with a total of 40 kW fed by 3 * 400 V, a pulse train controlled thyristor unit, and a fully configurable PID controller.
The flow temperature is measured with a PT100.
For safety, both an air flow switch and a thermostat switch off the heating in the event of a loss of air flow or overheating.
The most important parts are:

  •     Eurotherm PC3016 configurable PID controller
  •     Eurotherm EPack Light 3 PH / 65A thyristor unit
  •     PT100 and Air flow monitor
  •     Heating element of 40kW at 3 * 400Vac
  •     Mechanical and electrical design and implementation