Abstract: The electrical protection device comprises a plurality of sensors, a multiplexer and a sigma-delta type analog-to-digital converter. The converter comprises a sigma-delta modulator in series with a numerical decimation filter. The decimation filter comprises weighting coefficients ki, of level 1 to n, such that the product of the measuring range of the signals measured by the sensors and of the ratio ∑ l m ⁢ k i / ∑ l n ⁢ k i is less than the precision required for said signals, the coefficients of level 1 to m being the coefficients used during the stabilization time of the modulator. The coefficients of the filter of level 1 to m are preferably zero.

Abstract: An electrotechnical power supply system includes several power sources and interconnectable feeders, and an overall isolation monitor and at least one locator on each power source.All the overall isolations monitors and locators are connected together by a local data bus transmission network.A plurality of connecting circuit breakers are arranged between the power sources. A management unit is electrically connected to the transmission network for transmitting control signals to the overall isolation monitors, so as to switch some of the monitors to an inaction excluded mode, with the exception of a single one of them which operates as pilot in an active mode.