Here are a couple of wiring diagrams.
The first diagram is from the manufacture of the PID showing a 120v diagram and a 240v diagram.
The second diagram is mine, I changed things up a little. Even though the PID can run off 240v, I did not want that going to to it. So I'll run 120v to the PID and I want a wall receptacle so i can plug a fan, radio, light or anything else I may want to that would only need 120v.
Manufactures Wiring Diagrams:
My Wiring Diagram: