In order to increase the equipment availability and operating safety in industrial processes, strategies for the maintenance and servicing of plants supported by condition monitoring are getting more and more into focus. The increasing number of sensitive electrical equipment provides system protection with major challenges. Therefore, the correct function of all safety-relevant overvoltage protection devices is of elementary importance. This paper presents techniques for a newly developed condition monitoring system for power distribution protection, including sensor and processing, based on the quantitative measurement of the discharge current up to 40 kA passing through active conductors of a Surge Protection Device (SPD). In addition, it is possible to measure qualitative electromagnetic disturbances by specifically designed capacitive couplings. This allows preventative measures before actual failures of components and offers the possibility to investigate surge currents and their splitting in the individual areas of distribution systems.