Siemens SINAMICS G120 Installation Manual page 67

Operating the motor in a delta connection with 87 Hz characteristic
The motor only goes into field weakening above 87 Hz.
The higher motor power when operated with an 87 Hz characteristic has the following
disadvantages:
● The converter must supply approximately 1.73x current. Select a converter based on its
rated current - and not its rated power.
● The motor temperature increases more significantly than when operated with f ≤ 50 Hz.
● The motor must have windings that are approved for a voltage > rated voltage U
● As the fan impeller rotates faster, the motor has a higher noise level than operation with
f ≤ 50 Hz.
Power Module PM240-2
Hardware Installation Manual, 01/2020, A5E33294624B AL
4.4 Connecting the motor to the converter in a star or delta connection
In a delta connection, the motor is oper-
ated with a voltage and frequency above
its rated values. As a consequence, the
motor power is increased by a factor
√3 ≈ 1.73.
In the range f = 0 ... 87 Hz, the motor
can output its rated torque M
The maximum voltage U = 400 V is
available at a frequency of
f = √3 × 50 Hz ≈ 87 Hz.
Connecting
.
N
.
N
65