Siemens SINAMICS G120 Operating Instructions Manual page 76

Installing
4.5 Connecting the line supply, motor and converter components
Connecting a motor cable to an induction motor
Procedure
To connect the motor cable to an induction motor proceed as follows:
1. Open the motor terminal box.
2. Connect the motor in either a star or delta connection.
3. If you are using a shielded motor cable, you must do the following:
– Expose the shield of the motor cable in the area of the cable entry in the terminal box.
– Attach the cable shield to the motor terminal box using a suitable screw connection.
4. Close the motor terminal box.
You have connected the motor cable to the induction motor.
Depending on your application, you can operate the motor in the star or delta connection
(Y/Δ).
Examples for operating the converter and motor on a 400 V line supply
Assumption: The motor rating plate states 230/400 V Δ/Y.
Case 1: A motor is normally operated between standstill and its rated speed (i.e. a speed
corresponding to the line frequency). In this case, you need to connect the motor in Y.
Operating the motor above its rated speed is only possible in field weakening, i.e. the motor
torque available is reduced above the rated speed.
Case 2: If you want to operate the motor with the "87 Hz characteristic", you need to connect
the motor in Δ.
With the 87 Hz characteristic, the motor's power output increases. The 87 Hz characteristic
is mainly used with geared motors.
Before you connect the motor, ensure that the motor has the appropriate connection for your
application:
Motor is connected in the star or delta configuration
With SIEMENS motors, you will see a
diagram of both connection methods on
the inside of the cover of the terminal
box:
• Star connection (Y)
• Delta connection (Δ)
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Converter with CU230P-2 Control Units
Operating Instructions, 04/2015, FW V4.7 SP3, A5E34257946B AB