Siemens CU240B-2 Parameter Manual page 64

Parameters
List of Parameters
r0345[0...n] Nominal motor starting time / Mot t_start_rated
Access level: 3
Can be changed: -
Units group: -
Min
- [s]
Description: Displays the rated motor starting time. This time corresponds to the time from standstill up to reaching the motor
rated speed and the acceleration with motor rated torque (r0333).
Dependency: Refer to: r0313, r0333, p0341, p0342
p0346[0...n] Motor excitation build-up time / Mot t_excitation
Access level: 3
Can be changed: C(3), U, T
Units group: -
Min
0.000 [s]
Description: Sets the excitation build-up time of the motor.
This involves the delay time between enabling the pulses and enabling the ramp-function generator. The induction
motor is magnetized during this time.
Caution: If there is insufficient magnetization under load or if the acceleration rate is too high, then an induction motor can
stall (refer to the note).
Note: The parameter is calculated using p0340 = 1, 3.
For induction motors, the result depends on the rotor time constant (r0384). If this time is excessively reduced, this
can result in an inadequate magnetizing of the induction motor. This is the case if the current limit is reached while
building up magnetizing. For induction motors, the parameter cannot be set to 0 s (internal limit: 0.1 * r0384).
For permanent-magnet synchronous motors and vector control, the value depends on the stator time constant
(r0386). Here, it defines the time to establish the current for encoderless operation immediately after the pulses
have been enabled.
p0347[0...n] Motor de-excitation time / Mot t_de-excitat.
Access level: 3
Can be changed: C(3), U, T
Units group: -
Min
0.000 [s]
Description: Sets the de-magnetizing time (for induction motors) after the inverter pulses have been canceled.
The inverter pulses cannot be switched in (enabled) within this delay time.
Note: The parameter is calculated using p0340 = 1, 3.
For induction motors, the result depends on the rotor time constant (r0384).
if this time is shortened too much, then this can result in an inadequate de-magnetizing of the induction motor and
in an overcurrent condition when the pulses are subsequently enabled (only when the flying restart function is acti-
vated and the motor is rotating).
1-64
Calculated: -
Scaling: -
Unit selection: -
Max
- [s]
Calculated: p0340 = 1,3
Scaling: -
Unit selection: -
Max
20.000 [s]
Calculated: p0340 = 1,3
Scaling: -
Unit selection: -
Max
20.000 [s]
SINAMICS G120 / Control Units CU240B/E-2 Parameter Manual (LH11), 01/2011
Data type: FloatingPoint32
Data set: MDS
Factory setting
- [s]
Data type: FloatingPoint32
Data set: MDS
Factory setting
0.000 [s]
Data type: FloatingPoint32
Data set: MDS
Factory setting
0.000 [s]
© Siemens AG 2011 All Rights Reserved