Siemens SINAMICS GL150 Operating And Installation Instructions page 52

Preparations for use
4.1 Notes for system integrators
● In the event of external tripping of the circuit breaker, prevent the converter from shutting
● Many circuit breakers do not have a mechanically leading contact. You can implement the
52
down with unattributable follow-up messages. Therefore, ensure that the converter is
definitively switched to current-free with a "leading contact". This must happen before the
main contacts of the circuit breaker open. A corresponding message is also generated by
the converter open-loop controller ("external tripping of circuit breaker").
contact in various ways:
– If you are using a digital over-current relay, you must use it to detect all shutdown
conditions of the circuit breaker internally and externally (e.g. Buchholz fault). You must
program two tripping contacts with equivalent functions. One tripping contact is wired
to the "leading contact" input of the converter. The second tripping contact is wired to
the undervoltage release of the circuit breaker.
– The voltage at the undervoltage coil is queried via an optocoupler. The output of the
optocoupler is wired to the "leading contact" input of the converter. We recommend
using a Phoenix ST-OE 3 optocoupler with 24 V short-circuit-proof DC voltage output.
The exact type will depend on the auxiliary voltage of the switchgear (input data of the
optocoupler).
NOTICE
Lack of intrinsic device protection for the circuit breaker
If the fuseless version of the converter is being used and the circuit breaker does not
have any additional intrinsic device protection, this can result in damage to the power
unit.
Ensure that the circuit breaker has additional intrinsic device protection. The intrinsic
device protection must be switched off within 100 ms of a short-circuit current at the
latest.
SINAMICS GL150 6SL38503UM114PA0Z
Operating Instructions 04/2017