How do you shut down the emp in killzone 3?

Answer 1

In that bottom Tactical Spawn Point on the Turbine map (the one in the tunnel at the back of the map under the mountain side), there is a little control panel in the room where the spawn is. If you're facing that ammo box at the bottom of the stairs in that room, turn around and you'll see a button on a pedestal. When you hear the alarm going off, you can press that button and it shuts off the EMP.

See the related link.