7 7.5 7.5.1 DC-bus operation Basic dimensioning General information Use the time/performance diagram to optimise the DC-bus performance of all axes for a complete machine cycle. Utilisation factor PleaseconsidertheutilisationfactorswhendeterminingP DCtotal .Reducethe power requirements if the rated power is not fully used. Simultaneity factor Please consider the simultaneity factor when determining P DCtotal . Reduce the power requirements if the drives do not run simultaneously or in opposite direction (braking). Braking After determining the brake power P BRtotal , ensure that the brake power can be provided by the brake choppers and brake resistors in the DC bus.
Other conditions The power supply unit must be able to provide the required power (arithmetic mean). The overload requirements must be within the permissible range: ( 7.4.2) ƒ 3-min cycle (1 min overload with 150 %/2 min recovery time with 75 %) ƒ 5-s cycle (0.5 s overload and 4.5 s recovery time with 75 %) For detailed information on the overload capacity, please see the Technical data. 7.5-2 EDS94SPP101 EN 3.1-04/2007