Control of the isolation of intervention units used in an electrolysis hall for the production of aluminum by electrolysis igneous.

continuously monitoring system isolating a mass in relation to its neighbors, comprising: a) a ICC (100); b) a first portion (103) of measuring circuit connecting said ground (70) to a first terminal ( 101) of said ICC; c) a second portion (104, 201, 108, 109) measuring circuit for connecting the second terminal (102) of said ICC in each of the adjacent masses (80, 90), said second portion comprising at least one relay (201) that connects alternately said IMD to a portion (104, 201, 108; resp. 104, 201, 109). (80, resp 90) of the measuring circuit connected to said adjacent mass .Ledit ICC alternately injected to each switch, a current in the measurement circuit so as to measure the resistance of said circuit.Ledit system is used to regularly monitor the insulation of the various parts of a response unit to act in a electrolysis cell, the measuring circuits being designed preferably so that it uses only one ICC. The system may also include a system of regular monitoring of power circuits.