Siemens SINAMICS G130 Engineering Manual page 166

General Engineering Information for SINAMICS
Engineering Information
•
SIMOVERT A converters are generally designed for 4Q operation, i.e. without modification or upgrading.
When SINAMICS is chosen as a replacement converter, it is therefore necessary to clarify whether the
unit is required to operate in regenerative mode for the application in question so that the correct unit for
either 1Q or 4Q mode is selected.
•
Due to their pulse width modulation technique, converters like SINAMICS generate higher noise levels in
the motor than SIMOVERT A units. An increase in motor noise of about 5 dB(A) to 7 dB(A) must therefore
be expected when a SIMOVERT A converter is replaced by a SINAMICS converter.
It is also important to note the potential problems affecting the motors:
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Voltage stress on the motor winding
•
Bearing currents in the motor bearings.
Solutions to counter these problems are available. For example, motor reactors or motor filters can be installed at the
SINAMICS converter output, or the motor can be retrofitted with an insulated bearing in an approved service
workshop.
1. Measures recommended when replacing a 6SC23 SIMOVERT A converter for a line supply voltage of 500 V
1.1 Operation with 1LA6 motors:
•
Use a motor reactor on the SINAMICS converter to reduce the voltage rate of rise dv/dt and retrofit an
insulated bearing to the non-drive end of the motor
or
•
Use a dv/dt filter plus VPL on the SINAMICS converter, but do not modify the motor
1.2 Operation with 1LA1 motors with 6-pulse winding:
•
No measures required
2. Measures recommended when replacing a 6SC23 SIMOVERT A converter for a line supply voltage of 690 V
2.1 Operation with 1LA6 motors:
•
Use a dv/dt filter plus VPL on the SINAMICS converter, but do not modify the motor
2.2 Operation with 1LA1 motors with 6-pulse winding:
•
No measures required
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Notice! If the motor is retrofitted with an insulated non-drive end bearing and also has a speed encoder, the
encoder must also be insulated or replaced by an encoder with insulated bearings.
SINAMICS Engineering Manual – May 2008
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© Siemens AG
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