Siemens SIMOTICS T-1FW68, Configuration Manual

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Configuring
5.1 Configuring workflow
1FW68 radial segment motors
Configuration Manual, 08/2021, A5E51132930B AA
91
5.1.7 Uneven current load
If the current load of the three phases is continuously uneven, the motor must only be
operated at no more than 70% of its rated torque, see also M
0
* in Chapter "Technical
data and characteristics".
For precise dimensioning, please contact your local Siemens office.
Note
Not all of the three phases are necessarily evenly loaded in all motor operating modes.
Examples of uneven current load:
• Motor is at a standstill with current being fed to it, e.g. for:
– Compensation of a weight force
– Start-up against a brake system (damping and impact absorption elements)
• Low speeds over a longer period (n << 1 r/min)
• Very low oscillating rotary motion (distance along the circumference of the rotor
segment < pole width)
5.1.8 Motor torque-speed diagram
Checking torques and speeds
At high speeds, the maximum available motor torque is limited by the available DC link
voltage.
The speeds occurring in the motion sequence can exceed the maximum speed n
MAX,MMAX
specified for the motor type at the maximum torque M
MAX
. In this case, a check must be
made based on the motor torque-speed diagram. This diagram is included with the
motor specifications.
Figure 5-5 Motor torque-speed diagram