The application is a beer homebrew system.
The hot-liquor-tank (HLT) is a 25 liter tank heated with one element with two loops (800+1200w). I expect to use 20-40 minutes to heat water to different levels after a full refill during the brew process.
The boil kettle will have a normal batch size of 30 liters and is heated with two elements. One with two loops (800+1200w) and the other is a single 2000w element. I expect heating from wort mash temperature of 65C to boil will take 20-30 minutes.
The plan is to use two pid processes to control total of 5 relays. The set points will change according to the advancing states of the brew process.