We are glad to inform you about the actualization of MAC-QS series (high speed AC electric machines for dynamometers). As a result of our continuous product improving efforts we have introduced several changes on 250’s frame. The objectives of these modifications are the reduction of the rotor inertia and the improvement of machine performances at high speed operation (between 6,000 and 10,000 rpm). This results in a significantly low vibration levels, factor with relevant importance in the high speed dynamometers. The actualized motor datasheets are now available at our web site.