it isnt sending a signal to the relay to turn the dust collector on.
Is this still the issue?
I wired up a test circuit on my Uno and ran the code from post #6. I used a LED on pin 11 to watch the dust collector relay output. When one of the analog inputs goes high the LED does turn on and then LED turns off, after a delay, when the input is brought low. So, the code seems to be working. If the relay is not turning on it is looking like a hardware problem.