Supressor de sobretensões

Surge arrester comprising a stack of varistor blocks (10), for example of zinc oxide, arranged between two end electrodes (11, 12) in an elongated insulating casing (23) of polymeric material, for example silicone rubber. The stack of varistor blocks and the electrodes are axially surrounded by compression loops (14-17) of insulating material for providing the necessary axial contact pressure between the different elements (10, 11, 12) in the surge arrester. According to the invention the varistor stack (10) and the compression loops are radially surrounded by a bursting-preventive bandage (21) of insulating material with openings (22) for pressure relief in case of internal short circuit in the surge arrester.