Siemens SINAMICS S150 - Bypass Without Synchronizer (P1260 = 3)

Functions, monitoring, and protective functions
9.4 Extended functions
Drive converter cabinet units
346 Operating Instructions, 07/07, A5E00288214A
9.4.2.3 Bypass without synchronizer (p1260 = 3)
Description
When the motor is transferred to the supply, contactor K1 is opened (following converter’s
pulse inhibit). The system then waits for the motor excitation time to elapse after which
contactor K2 is closed and the motor is run directly on the supply.
If the motor is switched on in a non-synchronized manner, when activated an equalizing
current flows and this must be taken into account when designing the protective equipment
(see diagram "Circuit bypass without synchronization").
When the motor is being transferred from the supply by the converter, initially contactor K2 is
opened and after the excitation time, contactor K1 is closed. The converter then captures the
rotating motor and the motor is operated on the converter.
Contactor K2 must be designed for switching under load.
Contactors K1 and K2 must be interlocked against closing at the same time.
The "flying restart" function must be activated (p1200 = 1).
M
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K 1 K 2
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Figure 9-12 Example circuit for bypass without synchronization
Activation
The bypass with synchronizer (p1260 = 3) can be triggered by the following signals (p1267):
● Bypass by means of control signal (p1267.0 = 1):
The bypass can be activated by means of a digital signal (p1266) (e.g. from a higher-level
automation system). If the digital signal is canceled, a changeover to converter
operations is triggered once the debypass delay time (p1263) has expired.