Siemens SINAMICS G220 - Page 79

In a delta connection, the motor is operated with a voltage and frequency above its rated
values. As a consequence, the motor power output is increased by the factor √3≈1.73.
In the range f=0…87Hz, the motor can output its rated torqueM
N
.
The maximum voltage U= 400V is available at the frequency f=√3×50Hz ≈ 87Hz.
The motor only goes into 󹪝eld weakening above 87Hz.
The higher motor power output when operated with an 87 Hz characteristic has the
following disadvantages:
• The converter must supply approximately 1.73 times the current. Select the converter based
on its rated current and not on its rated power.
• The motor temperature increases more signi󹪝cantly than when operated with f≤50Hz.
• The motor must have windings that are approved for a voltage> rated voltage U
N
.
• The faster rotation of the fan impeller means that the motor has a higher noise level than
when operated with f≤50Hz.
Application planning
4.12Star connection of the motor or 87Hz delta connection
SINAMICS G220 converter
Operating Instructions, 04/2024, FW V6.2, A5E51781573B AB 77