The BE1-511 is a single-phase or three-phase overcurrent relay depending on the specific model variant. It utilizes a ruggedized microprocessor to sample analog current inputs via internal A/D (Analog-to-Digital) converters. Unlike electromechanical relays that rely on the physical interaction of magnetic fields to rotate a disc, the 7SR511 calculates the RMS (Root Mean Square) value of the current and compares it against programmed thresholds in real-time.
This section helps you verify that the correct device variant was shipped. It includes block diagrams showing how overcurrent (50/51), earth fault (50N/51N), and negative sequence (46) elements interact. If you are unsure whether to set the relay for "Radial" or "Parallel" feeder mode, start here. 7sr511 manual