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 device for monitoring a surge arrester, including: a grounding line; a measuring unit including one or more analog measuring circuits for measuring the electric current passing through the grounding line; an electronic processing unit for receiving measuring signals from the measuring circuits; a data storage medium for storing monitoring data produced by the processing unit; a base module, which accommodates the grounding line and the measuring unit; and an auxiliary module, which accommodates the processing unit and the data storage medium and is detachably mountable to the base module. When the auxiliary module is mounted to the base module, the components of the modules are connected to each other through a connector member provided on the base module and a corresponding connector member provided on the auxiliary module.

Abstract: A device for monitoring a surge arrester, including: a grounding line; a measuring unit including one or more analogue measuring circuits for measuring the electric current passing through the grounding line; an electronic processing unit for receiving measuring signals from the measuring circuits; a data storage medium for storing monitoring data produced by the processing unit; a base module, which accommodates the grounding line and the measuring unit; and an auxiliary module, which accommodates the processing unit and the data storage medium and is detachably mountable to the base module. When the auxiliary module is mounted to the base module, the components of the modules are connected to each other through a connector member provided on the base module and a corresponding connector member provided on the auxiliary module.