Rz was an electric locomotive built by ASEA to test out asynchronous motors.
It was built in 1982 and closely related to the Rc-series.
It was test run until 1989 on Siljansbanan, but there was never any mass production of it.
After ASEA merged with Brown, Boveri & Cie to form Asea Brown Boveri in 1988 the development of asynchronous motors was moved to Switzerland.
In 1992 the engine was donated to the Swedish Railway Museum, but they were not particularly interested in it and in 1999 it was moved to Örebro to become a parts locomotive.