139 electric locomotives of the class 17E were created in 1993 and 1994 by rebuilding locomotives of the class 6E1. Their electrics were modernized with improved wheelslip control and regenerative braking systems. The more powerful regenerative braking sometimes led to the problem that the substations could not take all the power generated by the locomotives. This led to a further rebuild into the class 18E from 2000 when, among others, the regenerative brake was changed into a rheostatic one. 