Pot Tending Assemblies (PTA) or Pot Tending Machines (PTM) are used in electrolysis plants to carry out the work on the electrolysis cells. These include replacement of worn anodes by new ones, sampling of molten metal produced in the cells and sampling or top-ups of electrolyte. In order to carry out this work, plants are generally equipped with one or more service units including an overhead traveling crane which can be relocated above the electrolysis cells,along series of cells, and one or more service modules including a carriage able to be moved on the overhead traveling crane, and handling and servicing devices called “tools”, such as shovels, grips, tappers and hoists. Pot Tending Assembly (PTA) or Pot Tending Machines (PTM) are designed to assist the operator in performing maintenance activities inside the cells of an electrolysis unit. These units typically include a crane for moving service modules,which may be equipped with servicing devices known as tools.