Another little update. I’ve been working on the interface some more, as well as getting the panel wired up. I still need to get the low voltage stuff wired to the PID controllers, get the modbus wired and install the wifi dongle/antenna cable.
I’m using some of the unused outputs (alarm ouputs) on the PID controllers to drive the SSR’s for the two pumps. I’ve also wired the E-Stop to the coils on the two 2-pole contactors for the heating elements in case I need to shut down. This will let me keep control power live.
The PID’s have a nice feature on them where you wire in a Current Transformer. This will let you see how much current is going through each SSR. This allows me to ensure that I can tell if a heating element is open circuit if the SSR is on and I see no current, or that the SSR is shorted if the SSR is commanded off and I see current.
Also, since then, I got a medical grade Touchscreen computer and a mounting arm off eBay. This will be my new interface for the brew panel, and will also allow me to check on the temp chambers. Here’s a video of the interfaces of both:
Here’s some pictures of the LCD touchscreen computer:
And some pictures of the panel: