I don't know if it's the right choice, but here's what I ordered to run my compressor:
https://www.mouser.com/ProductDetail...Qgm8BEGA%3D%3D
The compressor motor says 21A and that SSR is good for 30A.
I watched a few disassembly videos on discount 30A SSRs that are on Amazon and eBay right now and they're made using as 12A triac! So the triac is only rated for about 1/3 of the total device... so I bought a quality USA unit instead.
I'm hoping I can do PWM and slow-start the compressor motor with this, we shall see. I know I learned that most SSRs are actually "zero crossing" and don't change strate until the AC waveform crosses zero. So I ordered this one that is supposed to be instant.
I would have preferred someone made a "Large single phase AC motor speed controller" that I could just send a reference voltage and it did the work, but I couldn't find anything like that!