Siemens 1FT7 Configuration Manual page 73

When the machine is running (with shaft operated by motor or separately driven) at speeds
higher than n
might be induced in the winding. This can cause irreparable damage to the converter. No
operation is therefore permissible above the speed n
other additional measures. Siemens AG accepts no liability for any damage occurring as a
result of failure to pay heed to this danger warning.
Torque limit when operating on a SINAMICS S120 drive system with field weakening
The field weakening function is active as standard on the SINAMICS S120 drive system. A
field-weakening current is injected in such a way as to enable operation to the right of or
above the voltage limiting characteristic. The shape of the limiting characteristic for field
weakening is determined by the winding version (armature circuit) and the magnitude of the
inverter output voltage. The characteristic curve is plotted for each winding version in a
separate data sheet. The torque-speed diagrams for different inverter output voltages are
then assigned to each data sheet:
Diagram [a]
Diagram [b]
Diagram [c]
When field weakening is used, the limiting characteristic drawn as a continuous line applies.
1FT7 Synchronous Motors
Configuration Manual, (PFT7S) 01/2009, 6SN1197-0AD13-0BP2
CAUTION
, a voltage in excess of the maximum permissible converter voltage
max Inv
Technical data and characteristic curves
4.1 Operating range and characteristics
max Inv
380 V
425 V
460 V
without protective measures or
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