Starting Mode: Direct On-Line; Starting Mode: Motor Heating - Siemens Sirius 3RW44 System Manual

Device functions

6.2.5 Starting mode: direct on-line

Run-up recognition

6.2.6 Starting mode: motor heating

Typical applications for motor heating
6-10
If direct on-line starting mode is set, the motor voltage is immediately increased
to line voltage when it receives the start command. This resembles the starting
behavior with a contactor, i.e. the starting current and start torque are not
limited.
Notice
Due to the high starting current of the motor, the error "current limit exceeded"
may occur in direct on-line starting mode. It may be necessary to select a larger
dimensioned soft starter.
The soft starter features an internal run-up recognition. If a completed motor
run-up is recognized, the internal bypass contacts will close and the thyristors
are bridged.
If IP54 motors are used outdoors, condensation occurs in the motor during
cooler periods (e.g. overnight or in winter). This may lead to leakage currents or
short circuits when the units are switched on.
A pulsating DC current is fed into the motor winding to warm it up.
If the motor heating starting mode is selected, a heating capacity can be
entered in the settings. This capacity should be chosen in such a way that the
motor will not be damaged.
Used e.g. in outdoor drives to minimize condensation inside the motor.
SIRIUS 3RW44 manual
GWA 4NEB 535 2195-02 DS 01