Preparations for use
4
When carrying out any work, carefully observe the information provided in Chapter "Safety
4.1
Notes for system integrators
4.1.1
Requirements for the circuit breaker provided by the customer
To ensure adequate protection for converters, the circuit breaker provided by the customer
must fulfill the following conditions:
● The tripping time of the circuit-breaker must not exceed 80 ms.
● The circuit-breaker must be equipped with an undervoltage release. The undervoltage
release (undervoltage release coil) is controlled via the release circuit, into which the
"undervoltage release" output of the converter must be integrated as well. The auxiliary
voltage from the switchgear (this is a reliable supply) is used as the supply.
Note
In power converters, the undervoltage release is not normally supplied from voltage
transformers that are connected to the main supply network. As a consequence, an
undervoltage condition in the main line supply does not result in shutdown/trip by the
switchgear or the voltage transformer.
● Avoid additional delay times when controlling the circuit breaker. All commands from the
converter to the circuit breaker must act directly without intervention of coupling relays.
● There must be a checkback signal for each of the the circuit breaker statuses CLOSED and
OPEN. The checkback signals must occur promptly, typically within a second.
● Provide time-overcurrent protection.
● Under no circumstances may the circuit breaker be electrically or mechanically externally
closed. A mechanical interlock of the manual ON command at the circuit breaker prevents
destruction of the converter as a result of an uncoordinated switch-on operation.
SINAMICS SL150 6SL39616RC100AA02
Operating Instructions Rev.201910281458 EXAMPLE
39
