A protection arrangement of an electric machine which includes a plurality of solid elements layered one after another between a terminal box and a stator of the electric machine. Each of the solid elements includes a cable hole, and the cable holes are arranged to at least partially overlap with each other in order to have a cable channel of the successive cable holes through the solid elements. At least a part of the solid elements are adjustable in a radial direction of the cable channel for making a diameter of the cable channel equal to or smaller than a diameter of the electric cable input in the cable channel in response to adjustment in the radial direction. The protection arrangement comprises a locking mechanism which immobilizes the at least part of solid elements.