A circuit for supplying electrical power at a rated direct current of 20-100 kA to an electrolysis cell is provided. The circuit comprises an upstream and a downstream busbar connected to each other with a short-circuiting device which, when closed by an actuating mechanism, allows the busbars to be electrically connected to each other. An anode bar is equipped with an anode connection interface and a cathode connection interface, for connection to the anode and cathode, respectively. The cathode connection interface is connected to the downstream busbar. The circuit comprises means for absorbing movement of elements of the circuit due to thermal expansion. A disconnector connected to the upstream busbar and to the anode bar is opened by an actuating mechanism and it electrically disconnects the upstream busbar and the anode bar from each other after a non-zero time interval Tm when the short-circuiting device has been closed.