Due to the ability of the DC motors to absorb very high currents at low speeds, a rheostat needed to be connected in series to the traction motors when starting the train, to avoid drawing excessive current. The rheostat was gradually excluded as speed builds up and is also reintroduced when a transition to another is made; like almost every Italian electric locomotive since E.626, rheostatic exclusion was commanded through a controller (formed by a lever mounted on a curved notched support, commonly called respectively "maniglione" and "roncola" in Italian) subdivided into several notches, each representing a portion of the rheostat, plus four (one for each combination) special intermediate "end combination" notches.