Siemens SINAMICS G115D Operating Instructions Manual page 78

Wiring
5.10 Connecting the motor
Function description
Operating the motor in a star connection
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.
76
In a star connection, the motor can provide its
rated torque M
N
quency f .
N
Rated voltage U
N
frequency f = 50 Hz.
N
The motor goes into field weakening above the
rated frequency. In field weakening, the avail‐
able motor torque decreases linearly with 1/f.
In field weakening, the available power re‐
mains constant.
In a delta connection, the motor is operated
with a voltage and frequency above its rated
values. As a consequence, the motor power is
increased by a factor
In the range f = 0 ... 87 Hz, the motor can out‐
put its rated torque M
The maximum voltage U = 400 V is available at
a frequency of f = × 50 Hz ≈ 87 Hz.
SINAMICS G115D Wall Mounted distributed drive
Operating Instructions, 07/2023, FW V4.7 SP14, A5E52808211A AA
in the range 0 ... rated fre‐
= 400 V is available at a rated
≈ 1.73.
.
N
.
N