Siemens SINAMICS S120 Function Manual page 219

Calculation example:
K
E
Result in formula above: R
The resistance of the braking resistor must not exceed 22.9 Ohm, which means that a 17
Ohm braking resistor (P
● The EMF of the PE spindle motor must not exceed 1.4 kVeff.
● Correct parameterization of the drive line-up:
Configuration example
An example of a configuration recommended to achieve perfect operation of the integrated
voltage protection function can be seen below.
Figure 6-6
Safety information
The integrated voltage protection function is deactivated at DC link voltages lower than 450
V. Kinetic energy is converted to heat loss in the drive system and motor. If the power loss
is too high or this operation takes too long, the drive may be subject to thermal overload.
Drive functions
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
= 145 V n = 10.000 min
eff max
max
In cases where the "Integrated voltage protection" function is not activated with the
appropriate parameter setting p1231 = 3, the maximum motor speed is automatically
limited to a non-critical value. An alarm message is also output.
Example of a configuration recommended for application of integrated voltage protection
DANGER
, Z = 2, L = 15.7*10
-1
P A
= 22.9 Ohm
Brake
= 25kW) is sufficient here.
6.10 Integrated voltage protection
H
-3
Basic functions
219