A vacuum arc interrupter that includes a vacuum chamber assembly and a pressure chamber assembly. The vacuum chamber assembly includes a first, fixed contact disposed within the vacuum chamber and a second, movable contact disposed within the vacuum chamber. A rod is coupled to, and in electrical communication with, the second contact. The rod is structured to move between a first position wherein the second contact is spaced from the first contact and a second position where the first and second contacts are in electrical communication with each other. The pressure chamber assembly has a gas generation device and a cylindrical barrel defining a pressure chamber with a first end and a second end. The barrel second end has an opening. A piston assembly is disposed in the pressure chamber and coupled to the rod, which passes through the second, open end. The gas generation device is coupled to the pressure chamber assembly and in fluid communication with the barrel and the piston assembly. Upon generation of a gas by the gas generation device, the piston moves within the barrel causing the rod to move from the first position to the second position.