A braking unit includes a braking means and means, configured to receive power from a power line, for engaging and disengaging the braking means. A first power signal line is provided that is connected to the means for engaging and disengaging said braking means and a second power signal line is also provided that is connected to said means for engaging and disengaging said braking means. The first power signal line is connected to the means for engaging and disengaging the braking means via a first power switching device and the second power signal line is connected to the means for engaging and disengaging the braking means via a second power switching device.