Siemens SINAMICS G150 Operating Instructions Manual page 424

Functions, Monitoring, and Protective Functions
9.2 Drive Functions
Since the type plate data provides the initialization values for identification, you must ensure
that it is entered correctly and consistently (taking into account the connection type
(star/delta)) so that the above data can be determined.
It is advisable to enter the motor supply cable resistance (p0352) before the standstill
measurement (p1910) is performed, so that it can be subtracted from the total measured
resistance when the stator resistance is calculated (p0350).
Entering the cable resistance improves the accuracy of thermal resistance adaptation,
particularly when long supply cables are used. This governs behavior at low speeds,
particularly during encoderless vector control.
Figure 9-1
If an output filter (see p0230) or series inductance (p0353) is used, its data must also be
entered before the standstill measurement is carried out.
The inductance value is then subtracted from the total measured value of the leakage. With
sine-wave filters, only the stator resistance, valve threshold voltage, and valve interlocking
time are measured.
Note
Leakage values in excess of 35 to 40% of the rated motor impedance will restrict the
dynamic response of speed and current control in the voltage limit range and in field-
weakening operation.
Note
Standstill measurement must be carried out when the motor is cold. In p0625, enter the
estimated ambient temperature of the motor during the measurement (with KTY sensor: set
p0600, p0601 and read r0035). This is the reference point for the thermal motor model and
thermal R
422
Equivalent circuit diagram for induction motor and cable
/R adaptation.
S R
Converter cabinet units
Operating Instructions, 03/2012, A5E03263466A