The Siemens SIRIUS 3UG4825-2CA40 is a residual current monitoring relay with digital setting, designed for three-phase supplies. It measures residual currents from 30 mA to 40 A, covering the range from sensitive ground-fault detection up to higher leakage levels typical on larger feeders. The measuring circuit can detect currents as low as 10 mA, with a full-scale setting adjustable up to 43 A.
Configuration and Diagnostics
The relay features an error memory function and supports an external reset, allowing it to be integrated into a manual or automatic reset scheme. A delayed switching function of 2 seconds is available to avoid nuisance tripping on inrush or transient leakage. The initial value is set at 0.85 of the full-scale value, and the full-scale value is 1.1, indicating the trip threshold is adjustable within a band around the nominal setting.