« on: November 13, 2014, 01:01:35 PM »
Yes, I've been out for a while - brewing 90 gallons on a strict schedule for the wedding kinda burned me out for a bit. But I'm getting back into it with this...
So here's a hair-brained idea: what if I was able to reprogram the PLC on the Brew Magic to also control heating elements in the BK and HLT, as well as use the 2000W heater in the RIMS tube to actually raise the mash temp?
For those who aren't intimately familiar with the Brew Magic, it has a Unitronics V350 touch screen PLC in it, which is a 12 relay PLC. The Brew Magic is currently using 2(? - basically not many) of the relays.
Theoretically, the BK and HLT could be converted to electric fairly easily. Add element, add wiring, and use a simple controller like High Gravity has (with the turn knob) to control the heat output. Done, but not pretty.
If I wanted to go pretty, I could add programming into the PLC (with appropriately stepped relays) to control the BK and HLT elements.
BUT. What if I could reprogram the RIMS tube heater logic to work when I want to raise the mash, instead of just maintaining the mash? I know the element in place can do it, if you trick the program, but it's tedious. The Sabco software only operates the RIMS tube element if you are -4F to -0.01F from your set mash temperature. It will be off otherwise, and you are forced to use the propane burner to bring it up any farther than this. Here's my trick: If you have a steady mash temp at say, 152, and you want it to be 158... program the set point to be 154, then when it gets there, go to 156, then when it gets there, go to 158. And then you have a RIMS element works as a step masher! Ha.
So how crazy is this? I've searched the internet and no one has seemed to do this specific thing. There are plenty of conversions from super old BMs to electric (before they had the PLC), but none using the existing PLC with new custom software.
I already talked with our lead electrical engineer in the office and he seems to be quite excited about it. He also indicated that the reprogramming/wiring of the PLC would be the easiest part of this (from an EE perspective, of course). Rewiring the house for 30-50A and getting a condensate hood installed would be the difficult part, according to him. Ha.