The ISOMETER® iso1685DP is a user-friendly device used to monitor the insulation resistance of extensive systems designed as floating systems, and is applicable in AC/DC systems up to AC 1000 V/DC 1500 V. The specific measurement method (i.e. AMP+) also monitors the insulation resistance in installations where extremely high-system leakage capacitances to earth exist due to EMC interference suppression methods and the nature of PV power plants. Because it generates locating current pulses required for ground- fault location, the localization of a ground fault using permanently installed or mobile ground-fault locators is possible.