Abstract: A contact assembly includes: an arc extinguishing assembly including an arc extinguishing grid group located in an arc extinguishing chamber, and first and second arc guide plates located at two ends of the chamber; a fixed contact connected to an inlet terminal, where the fixed contact includes a U-shaped structure including first and second segments opposite to each other, the first segment is pivotally connected to a first pivot shaft, so that the fixed contact is rotatable between a first closed position and a first open position, the second segment is provided with a fixed contact point, and when the fixed contact is in the first open position, a free end of the second segment is close to the first arc guide plate; and a contact pressure member elastically abutting against the fixed contact to apply a force to the fixed contact to move it towards the first open position.