Tripping Of The Circuit-Breaker In Case Of Undervoltage; Dc-Link Short-Circuiter - Siemens SINAMICS SM150 Operating And Installation Instructions

The insulation resistance can be > 20 MΏ in new or small IT systems. To suppress the
message, disable the connection monitoring in Setup2. The A-Isometer monitors the insulation
resistance of the drive.
8.4.3.2

Tripping of the circuit-breaker in case of undervoltage

If a serious fault occurs (e.g. overload in the DC link), the drive is immediately disconnected
from the power supply by means of the safety shutdown function.
Residual voltages
This function cannot ensure that the drive stops immediately, nor can it ensure that residual
voltages do not still exist at the output terminals and within the unit.
High voltages can cause death or serious injury if the safety rules are not observed or if the
equipment is handled incorrectly.
Always carefully observe the "five safety rules (Page 17)".
The shutdown of the circuit-breaker is triggered by a safety contactor combination.
The plant-side circuit-breaker must be equipped with an undervoltage trip to ensure the wire-
break protection for the circuit-breaker OFF command. If a circuit-breaker OFF command is
issued as a result of an overvoltage trip, the circuit-breaker is switched off so that it is fail-safe.
8.4.3.3

DC-link short-circuiter

The short-circuiter is triggered if an overvoltage occurs due to a serious fault and it cannot be
brought under control by opening the circuit-breaker and unlocking the pulse block of the
machine.
When the short-circuiter thyristors are triggered, the circuit-breaker is always deactivated.
Once the thyristors have been triggered, an acknowledgement signal is output to the closed-
loop control system. Fiber-optic conductors are used to control gating of the thyristors and the
acknowledgement signals.
The short-circuiter is triggered by the Power Stack Adapter.
SINAMICS SM150 6SL3845-7NN46-7AA0
Operating Instructions 04/2017
WARNING
Operation
8.4 Functions
143