...and the PID

Well, I'm glad you posted that last photo. There's nothing very heavy duty in that PID. So, you're definitely going to need a relay. If the machine is 3-phase, you're going to need one with three sets of contacts (like the SIRAI). If you go solid state, then you can't use a cheap SSR; you'll need one that switches the three phases, like this http://www.crydom.com/en/tech/white-pap ... epaper.pdf I still think it would be best to get an electrician or ham radio operator to help you.