Good stuff. If the keg is warm it will take a bit longer than 36 hours. You could probably go 40 hours at 30 psi and then dial it back to 15psi +/-
Don't be tempted to shake the keg or do any of that stuff. Trust me if you follow this simple set of steps you will not get over carbed beer.
1: Know what the temp is at the bottom of the kegerator and ideally have a small fan running to circulate the air. I keep my temp under 2C (34-35F). This temperature will help you better calculate serving pressures.
2:When your done fermenting the beer cold crash it (cool it rapidly to 30-32F) if you can and leave it for a few days like that before kegging. If you don't have the facility to cool the fermenter in this way no worries. Rack it to the keg and cool it while carbing. (carbing will take a bit longer+4 hours)
3: 36 hours at30psi (longer if the beer was warm when you started the CO2)
4: Reduce to serving pressure.That wil depend on line lenhght and a few other factors. I have a simple two tap kegerator with 5 ft lines and this method works like a charm every time. 2 days after kegging I have beer ready to drink.
5:If it is not quite carbed enough (It will be most likely) just leave it for a couple more days at the set pressure and the beer will carb up.
12psi is my standard serving pressure but a Hefeweizen demands a bit more if style guidelines are something you want to follow. 15-16 psi on my setup would be right. Your setup will be different of course so there will inevitably be a bit of tweaking needed.
My two tap kegerator

My version of Edwort's Hefeweizen