Previous post with more photos: https://www.reddit.com/r/Motors/comments/dg4igo/second_hand_rotary_phase_converter_rpc_blew_out

The victim: 10hp Rotary phase converter [RPC] I acquired that worked at first but now has blown one start capacitor and is trying to blow out the new one.

I'm still learning about all things 3 phase, I don't claim to understand anything.

I tried to spin up the motor with different power tools in the shop and was never able to get close to it's operational RPM without a working start capacitor.

Instead I installed the new capacitor and it was very clear that it didn't break the circuit going to the capacitor.

Question 1: I believe this is the relay that controls the start circuit: https://imgur.com/cAiUKYS [one wire was disconnected when the photo was taken]

I'm a bit new to reading electronics schematics, so I don't understand how this relay is supposed to work. Is it completing a circuit when it receives a signal or when it doesn't receive a signal? How do I tell which wire is supposed to be the signal wire?

Question 2: Am I damaging anything when the device is powered on but the start circuit is not engaged? It makes a loud buzzing sound.

Question 3: Lastly, and this is likely a really stupid question, I put one lead from my multimeter to the ground connection and checked a few places for voltage expecting them to all read 110-120vac, but a few places I tested with the RPC running read 220vac! Is this expected behavior for an RPC/Three-phase power in general?