Variotech – … keep it simple independent of lift control. In the event of an uningended movement of the elevator with the doors open, a TÜV approved safety device (ENA3/REA3) that is independent of the existing lift … independent of lift control. In the event of an uningended movement of the elevator with the doors open, a TÜV approved safety device (ENA3/REA3) that is independent of the existing lift …