Siemens SINAMICS S120 Function Manual page 241

Vdc_max control
Figure 5-16
The switch-on level for V
● When the function for automatically detecting the switch-on level is switched off (p1254 =
0)
r1242 = 1.15 x p0210 (device connection voltage, DC link)
● When the function for automatically detecting the switch-on level is switched on (p1254 =
1)
r1242 = V
If several Motor Modules are supplied from a non-regenerative infeed unit (e.g. a Basic Line
Module), or for power failure or overload (for SLM/ALM), the V
activated for a Motor Module whose drive should have a high moment of inertia.
For the other Motor Modules this function must be disabled or monitoring must be set.
If the V
parameterization, the controllers can mutually influence one another negatively. The drives
can become unstable, individual drives can unintentionally accelerate.
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Switching the V
dc_max
-control (r1242) is calculated as follows:
dc_max
- 50 V (V
dc_max dc_max
control is active for several Motor Modules, then for an unfavorable
dc_max
control on/off
: Overvoltage threshold of the Motor Module)
Vector control
5.9 Vdc control
control may only be
dc_max
241