So I have been thinking about an all electric brewing system for a long time now. I am looking to brew 5-10 gallon batches with this system. I have a space in my garage that has access to a 240V 50 Amp receptacle and a 120V 15amp receptacle (another 120V 15 ammp receptacle is close and will power pumps, ect). I have decided to automate the system using an Arduino
Board (just like Yuri's system
Steam Boiler and MT:
The Arduino would control the pressure (read temperature) in the boiler by activating a hotwater heater element inside. The temperature in the MT would be controlled by activating a solenoid valve to realease the steam into the MT in which a thermocoupler is placed.
The Arduino would cotroller the temperature in the HLT, in which a thermocoupler is place, by activating a hot water heater element(s).
The Arduino would cotroller the temerature in the BK, in which a thermocoupler is place, by low-density hot water heater element(s). Ideally both the HLT and the BK would have lower wattage elements that could maintain the temperature (while the larger elements are disingaged).
I'm looking for advice on how to divide up the avaible power and what size elements should be used. For the boiler, Yuri uses a 240V 6000W element, which gives him 1500W at 120V with a 12.5A current draw. This seems to work well for him, so I'll probably do something similar unless people suggest otherwise. Before I propose a design, I would like to have clarification on downgrading a circuit for this particular application. Others have talked about using 75% or 80% of a circuits rating. Others still have decribed applications which seem to run equipment much closer to a circuits full capacity. What is the recommended protocol in this situation?
One 240V 1500W element connected to a 50A soild state relay (SSR) (Am I correct that SSRs are rated by the input current, so one would need a 50A SSR on a 50A line?).
The HLT would have two 240V 4500W elements and one 240V 1500W element connected to a 50A SSR and have independed switches for each (do they makes these at a reasonable price?). Or the two 4500W elements could be connected to one SSR and the 1500W element could be connected to another SSR . The goals is to disengaged the 4500W elements and engaged the 1500W element in order to maintain the temperature.
The BK would have two 240V 4500W extra low density elements connected to an SSR and one 120V 1500W extra low density connected to an addtional SSR (I have yet to find a 240V 1500W extra low density element).
This design would give me 9000W of power to heat up water in the HLT and 10,500W with the BK (the additional 120V 1500W element). Since the 240V 4500W elements on the HLT and the BK would not be running at the same time they would consume 37.5A (the 240V 1500W element on the HLT would not be engaged while the 4500W elements were). Additionally, the boiler would consume 6.25A, for a total of 43.75A (which is ~88% of the circuits 50A). If this maxium load is unsafe I can redue some of the specifications. It would be easy to reduce the Amps on the HLT with a 240V 3500W element. The boil kettle proves to be a bit more difficult. As of right now I can only find extra low density elements in 5500W and 4500W.
10,500W is enough power to bring 13 gallons of wort to a boil (with a temperature rise of 73 degrees) in 14 minutes.
I'm going to need a bit of help figuring out this project and I would like to thank everyone in advance for any assistance offered.