Operation On Motors With Switchable Windings - Siemens SIRIUS 3TK2810-0 Equipment Manual

7.2

Operation on motors with switchable windings

For motors with star-delta (wye-delta) changeover, direction reversal and pole-changing
functions, it must be ensured that the measurement input lines L1 - L2 - L3 of the standstill
monitor are always connected via the motor windings in order to detect standstill, as otherwise
the fault message "Wire break" prevents the output contacts from being enabled.
In the case of a 3-phase connection to a motor with star-delta (wye-delta) changeover, the
star (wye) contactor must be switched on, for example, after the motor has been switched
off, so that the connection of L1 - L2 - L3 via the motor windings is guaranteed.
If it is not possible or desirable to switch on the star contactor after the motor has been
switched off, the measurement inputs of the standstill monitor must be connected directly to
one of the motor windings in "1-phase circuit", i.e. terminals L2-L3 bridged to one end of the
winding and L1 to the other end of the same motor winding.
The same applies to motor connections with direction reversal or pole changing. If the motor
windings are switched over with a "3-phase" connection of the standstill monitor and the
resulting interruptions of the measuring circuit last longer than 2 s, the standstill monitor
detects a wire break fault. To prevent this fault from being stored when the changeovers are
completed, the fault storage should be deactivated by bridging the terminals X2-X3.
3TK2810-0 standstill monitor
Equipment Manual, 08/2023, A5E50307927002A/RS-AA/001
7.2 Operation on motors with switchable windings
Operator control
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