I made a PID controller for the brewery in order to keep the mash at a specific temperature enabling optimal enzyme activity. I ordered the PID and switches online. The pid controls 3 solid state relays, one for each phase. The brewery is heated with 2 6kW heating elements. I added a switch to the controller where you can set if one or two of the elements will be used. The switch controls two three phase relays so it you can choose which 3 phase power outlets will be powered. There is also a switch that controls a normal power outlet so you can turn the circulation pump on and off.