Abstract: A monitoring arrangement for monitoring a surge arrester which is connected to a live wire of a power network at a connection point in order to protect an electrical apparatus against incoming surges, the monitoring arrangement including: an analogue measuring circuit for sensing a current impulse through the surge arrester caused by an incoming surge in the live wire and producing a corresponding analogue measuring signal; an analog-to-digital converter for converting the measuring signal into digital signals; and an electronic processing device configured: to establish, based on the digital signals, a voltage peak value representing the highest voltage at the connection point during the incoming surge; and to establish, based on the voltage peak value and by means of a calculation model or look-up table, a maximum-voltage value representing an estimated maximum voltage across the electrical apparatus during the incoming surge.

Abstract: A monitoring arrangement for monitoring a surge arrester which is connected to a live wire of a power network at a connection point in order to protect an electrical apparatus against incoming surges, the monitoring arrangement including: an analogue measuring circuit for sensing a current impulse through the surge arrester caused by an incoming surge in the live wire and producing a corresponding analogue measuring signal; an analog-to-digital converter for converting the measuring signal into digital signals; and an electronic processing device configured: to establish, based on the digital signals, a voltage peak value representing the highest voltage at the connection point during the incoming surge; and to establish, based on the voltage peak value and by means of a calculation model or look-up table, a maximum-voltage value representing an estimated maximum voltage across the electrical apparatus during the incoming surge.

Abstract: A high voltage surge arrester, including 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 the varistor element and forms an outer surface of the apparatus, wherein the electric insulator includes a silicone-based rubber. The silicone based rubber includes particles chosen from the group consisting of Al2O3, BN and ZnO, to such an extent that the thermal conductivity of the silicone-based rubber is equal to or above 0.8 W/mK.

Abstract: A high voltage surge arrester, including 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 the varistor element and forms an outer surface of the apparatus, wherein the electric insulator includes a silicone-based rubber. The silicone based rubber includes particles chosen from the group consisting of Al2O3, BN and ZnO, to such an extent that the thermal conductivity of the silicone-based rubber is equal to or above 0.8 W/mK.

Abstract: An arrester includes at least one elongate outer first housing made of an electrically insulating material, a pair of electrical terminals at opposite ends of the first housing, an array of electrical components arranged in the first housing that form a series path between the terminals, and a voltage grading arrangement for providing a substantially uniform voltage gradient along the arrester, wherein the voltage grading arrangement includes (i) an elongated outer second housing, and (ii) capacitor circuitry arranged in the outer second housing, and wherein the outer second housing is arranged external to the outer first housing.

Abstract: An arrester includes at least one elongate outer first housing made of an electrically insulating material, a pair of electrical terminals at opposite ends of the first housing, an array of electrical components arranged in the first housing that form a series path between the terminals, and a voltage grading arrangement for providing a substantially uniform voltage gradient along the arrester, wherein the voltage grading arrangement includes (i) an elongated outer second housing, and (ii) capacitor circuitry arranged in the outer second housing, and wherein the outer second housing is arranged external to the outer first housing.