Siemens S120 Uneven current load, Motor torque-speed diagram, Checking the torques and speeds

Configuring the motor 5.1 Procedure

5.1.5Uneven current load

If the load is uneven over a long period of time, the motor must only be operated at no more than 70% of the rated torque (see also M0* in "Technical data").

For exact configurations, contact your local Siemens office.

NOTICE

Not all of the three phases are necessarily evenly loaded in all motor operating modes. Examples of uneven current load:

∙Standstill with current feed of the motor, e.g. for:

–Compensation of a weight force

–Start-up against a brake system (damping and impact absorption elements)

∙Low speeds over a long period (n << 1 [rpm])

∙Cyclic rotation (path on rotor circumference < pole width)

5.1.6Motor torque-speed diagram

Checking the torques and speeds

At high speeds, the maximum available motor torque is limited by the available DC link voltage. If the speeds that occur in the motional sequence are greater than the maximum speed nMAX,MMAX specified for the motor type at the maximum torque MMAX, you may have to check the torques and speeds using the motor torque-speed diagram. This diagram is included with the motor specifications.

Figure 5-4 Motor torque-speed diagram

1FW6 Built-in torque motors	67
Configuration Manual, 05/2009, 6SN1197-0AE00-0BP3