Siemens MICROMASTER 440 Operating Instructions Manual page 179

Issue 10/03
NOTE
The ramp-up and ramp-down times (P1120; P1121) of the ramp-function
generator (refer to Section 3.12.2) in the setpoint channel should only be set so
fast that when accelerating and braking, the motor speed can follow the
setpoint. This then guarantees the optimum functioning of the speed controller
pre-control.
The starting time r0345 is a measure for the overall moment of inertia of the
machine and describes that time in which the unloaded drive can accelerate
from standstill to the rated motor speed P0311 with the rated motor torque
r0333.
r0345 =
If these secondary conditions match the particular application, then the starting
time can be used as the shortest value for the ramp-up and ramp-down times.
MICROMASTER 440 Operating Instructions
6SE6400-5AW00-0BP0
⋅ ⋅ π
2 n
T = Θ ⋅ Mot , rated =
starting
⋅
60 M
Mot , rated
⋅ ⋅ π
2 P 0311
P 0341 ⋅ P 0342 ⋅
⋅
60 r 0333
3 Functions
179