Patent ID: 8717732

Claim:
A high voltage surge arrester, comprising a varistor element arranged so as to be connected to a high voltage source and to carry a high voltage when being positioned in its operative position, and an electric insulator that encloses and is in contact with said varistor element and forms an outermost surface of the high voltage surge arrester, wherein said electric insulator consists of a silicone-based rubber, characterised in that the silicone based rubber comprises particles chosen from the group consisting of Al 2 O 3 , BN and ZnO, to such an extent that the thermal conductivity of said silicone-based rubber is equal to or above 0.8 W/mK, in that the particles are present in an amount of 25-75 volume % in relation to the volume of the total composition of the silicone based rubber of the electrical insulator, and in that the particles have an average particle size of 0.1-100 μm.